Pathology-Respiratory System

Question 1

A 66 year old male with a history of smoking comes to see you complaining of difficulty breathing. You decide to do a pulmonary function test and analyze his results. What results would you expect to find if this patient has COPD?

Answer 1

COPD is a disease with decrease expiration.

Question 2

A patient comes to see you with an FVC of 5L and and FEV1 of 4. 20 years later he comes back to see you with COPD that has caused 50% airway obstruction from the last time you saw him. What are his FVC and FEV1 values now?

Answer 2

Last time you saw him, he had an FVC:FEV1 ratio of 80%. If his airway obstruction has increased by 50%, his FVC:FEV1 ration should now be 40%. (FEV1 = 2 and FVC = 4.5ish).

Question 3

A 30 year old patient comes to see you with a TLC of 7L. He smokes for 30 years and comes back to see you with a diagnosis of COPD. What happened to his TLC ratio during this time?

Answer 3

It increased to around 8L. As the disease progresses you get air trapping in the lungs that adds to the amount of air the lung can hold.

Question 4

A 62 year old female comes to see you with a long history of smoking. She complains that she is coughing up cups of mucus. Tissue biopsy of her airways is shown below. What does this finding indicate?

Answer 4

This patient likely has chronic bronchitis. The Reid index is the ratio of mucus glands in the submucosa and the overall thickness of the bronchial wall. Smoking causes hyperplasia of these mucus glands, causing increased mucus production and increased Reid index. Diagnosis of chronic bronchitis is strengthened by a Reid index > 50%.

Question 5

How does chronic bronchitis contribute to development of COPD?

Answer 5

Mucus that gets trapped in the airways also traps air and causes obstruction.

Question 6

A 59 year old male comes to see you complaining of a productive cough and increased respiratory infections in the past year. He is also cyanotic. What is causing this patient to be cyanotic?

Answer 6

As airways are trapped, CO2 has a harder time getting out of the lungs and takes away some of the PAO2 in the alveoli. This results in a decreased PaO2 and cyanosis.

Question 7

A 79 year old male comes to see you for his regular visit. He has a long history of COPD. You run some tests to see how he is doing and find a decreased FEV1:FVC ratio. His blood O2 saturation is 80%. How might this patient’s chronic condition affect his heart?

Answer 7

Cor pulmonale. Hypoxia causes constriction of blood vessels around bronchioles that are not ventilating well. Mass constriction in diseases of COPD where ventilation is not great anywhere results in increased right ventricular pressure and eventual right heart failure.

Question 8

How does emphysema result in obstructive pulmonary disease?

Answer 8

Destruction of the alveolar air sacs causes loss of elastic recoil in the alveoli. This makes it more difficult to expel air from the lungs. Additionally, when air is accelerated out of the bronchiole during expiration, the air pulls on the wall causing it to collapse due to absence of elastic recoil in the damaged alveoli. This causes obstruction and air trapping.

Question 9

With all of the dust that gets into a normal person’s lungs, why doesn’t everyone have emphysema due to the alveoli’s inability to produce mucus and get foreign particles out of the lung?

Answer 9

The lung produces proteases that get rid of foreign particles. These proteases are what cause inflammation and destruction of alveolar walls in people with emphysema. Healthy people don’t get emphysema because they produce antiproteases (specifically alpha-1 anti-trypsin) that balance out the destructive activity of the proteases.

Question 10

Why do smokers have a particularly high risk for emphysema?

Answer 10

They are bringing all sorts of garbage into the lungs that activate proteases. The proteases overrun the anti-proteases and destruction of alveoli occurs.

Question 11

A patient comes to see you with difficulty breathing and jaundice. His liver biopsy is shown below and he is PAS positive. What is causing his condition?

Answer 11

Alpha-1 antitrypsin mutation (PiZ allele) that causes protein misfolding and accumulation in the ER of hepatocytes and causes liver cirrhosis. This also results in increased protease activity in the lungs due to decreased expression of the anti-protease, resulting in emphysema.

Question 12

How do the two categories of emphysema differ? What do smokers most commonly get?

Answer 12

Centriacinar vs. Panacinar. The functional unit of the lung is the acinus (where the terminal bronchiole opens into the alveolar air sacs). The first place smoke hits is the central acinus and smoke rises…so smokers are at risk for centriacinar emphysema, more severe in the upper lobes. People with alpha-1 antitrypsin mutation (PiZZ) are more prone to panacinar emphysema in the lower lobes.

Question 13

What people are at a genetically increased risk for developing emphysema if they smoke, but usually don’t develop it if they don’t smoke?

Answer 13

PiMZ allele heterozygotes. The PiM/PiM is the normal phenotype and the PiZ is the most common mutation causing alpha-1 anti-trypsin deficiency.

Question 14

What is the physiological basis behind the pink puffers in emphysema? What other symptoms do patients with emphysema present with?

Answer 14

In order to prevent bronchiole collapse, they purse their lips, prolong expiration and increase the back pressure as they try to keep the airway open. They also present with dyspnea, nonproductive cough, exercise (from labored breathing) and increased AP diameter of the chest, or barrel chest.

Question 15

A patient comes to see you with a nonproductive cough, weight loss and has labored breathing. His x-ray is shown below. What is causing the findings you see in his radiograph? How might his pulmonary function test be different from someone without this condition?

Answer 15

Note the barrel chest indicative of emphysema. Normally, the collapsing tendency of the lung is in equilibrium with the expanding tendency of the chest wall (marked by the functional residual capacity (FRC)). In emphysema, the lung loses its recoil and the chest wall has greater pull…causing barrel chest and an increased FRC.

Question 16

What are late complications of emphysema?

Answer 16

Hypoxemia (paO2 < 60 due to loss of capillaries around destroyed alveoli). Cor pulmonale (right heart hypertrophy and failure due to pulmonary blood vessel constriction and pulmonary hypertension).

Question 17

What type of hypersensitivity reactions usually cause asthma in what type of people?

Answer 17

Type I (allergen) hypersensitivity reaction in people who are genetically susceptible.

Question 18

A 12 year old girl comes to the ED after having an asthma attack during gym class. This was her first ever attack. Histological analysis of her airways would show prominence of what type of inflammatory cells? How do these cells cause asthma?

Answer 18

CD4+ T cells that become TH2 helper cells. The TH2 helper cells secrete IL-4 (allow plasma cell release of IgE), IL-5 (eosinophil recruiter) and IL-10 (promotes further TH2 cell differentiation).

Question 19

A 17 year old boy comes to the ED with his third asthma attack this year. How does exposure of the allergen cause immediate symptoms in this child?

Answer 19

PHASE I: Cross linking of IgE on mast cells causes degranulation and histamine release. Mass histamine release causes vasodilation (in arterioles) and vascular permeability (in post-capillary venules). PHASE II: mast cells produce leukotrienes C4, D4 and E4 (causing vasoconstriction, BRONCHOCONSTRICTION and increased vascular permeability). PHASE III: major basic protein released by eosinophils perpetuates bronchoconstriction.

Question 20

A 13 year old female presents to the ED with dyspnea and wheezing after playing in her PE class this morning. She has a productive cough. What would you expect to find in the sputum produced by her cough?

Answer 20

Curschmann spirals and Charcot-Leyden crystals (crystaline aggregates of major basic protein).

Question 21

What is it called when asthma get so bad that the bronchoconstriction does not relent and causes death?

Answer 21

Status asthmaticus

Question 22

What are some of the nonallergic causes of asthma?

Answer 22

Exercise, viral infection, aspirin (aspirin-induced bronchospasms and NASAL POLYPS) and occupational exposures.

Question 23

What causes the condition seen the lung biopsy of the patient below?

Answer 23

Note dilates airways where they should not be dilated. Necrotizing inflammation with damage to the airway wall causes airway dilation in bronchiectasis. This happens in cystic fibrosis (mucus plug -> infection -> inflammation and damage to the airway), Kartagener syndrome (defective dynein arm of cilia), tumors/foreign bodies (obstruction -> infection), necrotizing infections and allergic bronchopulmonary aspergillosis (hypersensitivity reaction to entry of aspergillis).

Question 24

A 22 year old male patient presents with sinusitis, infertility, sinus inversus, and recurrent pulmonary infection. What is your diagnosis?

Answer 24

Kartagener syndrome. The patient has a defective dynein arm of the cilia and you see defects where ever the body normally utilizes cilia.

Question 25

A patient comes to see you complaining of cough, dyspnea and foul-smelling sputum. She has a history of recurrent pulmonary infections. Labs show a decreased paO2 and pulmonary hypertension. If you took a biopsy of the lung, deposition of what material would may be present?

Answer 25

In bronchiectasis, patients have long-standing inflammatory reactions that dilate the airways. Long-standing inflammation causes production of amyloid (SAA) which is converted to AA and deposited in the tissue.

Question 26

A 17 year old male comes to see you with sneezing, congestion and runny nose. What is the most common cause of these symptoms?

Answer 26

Adenovirus is the most common pathogen that causes inflammation of the nasal mucosa and the common cold.

Question 27

A 6 year old female comes to your clinic during the springtime complaining of seasonal allergies. She also has a previous history of asthma and eczema. If you looked at the tissue in her nose what type of cells would you see in the inflamed tissue?

Answer 27

She has allergic rhinitis, a type I hypersensitivity reaction likely to pollen. This is commonly associated with asthma and eczema, and you would see eosinophilic infiltrate.

Question 28

You saw two patients today. One, a 7 year old boy with nasal polyps. Another, a 32 year old female with nasal polyps. If you rule out polyps due to allergic rhinitis, what would you suspect in each patient?

Answer 28

Child = cystic fibrosis. Adult = Aspirin intolerant asthma (aspirin-induced bronchospasms, nasal polyps and asthma).

Question 29

A 14 year old male presents with profuse epistaxis (nose bleeds). What type of tumor may be causing this condition?

Answer 29

Angiofibroma. It is almost exclusively seen in adolescent boys and is a benign tumor of the nasal mucosa composed of blood vessels and fibrous tissue.

Question 30

A 33 year old Chinese male presents with cervical lymphadenopathy. Biopsy of the lymph nodes reveals pleomorphic keratin-positive epithelial cells scattered in a background of lymphocytes. What is your diagnosis and what other disease is commonly associated with this? What other demographic commonly has this condition?

Answer 30

Nasopharyngeal carcinoma is a malignant tumor of the nasopharyngeal epithelium. The biopsy showed keratin positive cells, indicating that the tumor was epithelial in origin. This cancer is often associated with EBV and can also be found commonly in young African children.

Question 31

A 9 year old male presents with high fever, drooling, dysphagia, a muffled voice and inspiratory stridor. Physical examination of his mouth is shown below. What is the most likely pathogen causing this patient's condition? Is this a medical emergency?

Answer 31

H. influenza type b is the most common cause of acute epiglottitis in non-immunized AND immunized children. This is a medical emergency because the patient is at risk of airway obstruction of inflammation of the epiglottis continues.

Question 32

A 38 year old female presents to your clinic with a hoarse "barking" cough and inspiratory stridor. What pathogen often causes the patient to present with these symptoms?

Answer 32

Laryngotracheobronchitis (croup) causes inflammation of the upper airway and is most often a result of parainfluenza virus infection.

Question 33

A 58 year old female comes to see you complaining of hoarseness. She works as a waitress and says that it kind of goes away on the weekends but comes back when she goes to work. Tissue biopsy is shown below. What is your diagnosis of this patient?

Answer 33

Vocal cord nodules are overuse injuries that usually occur bilaterally (as seen below). Note that the biopsy is composed of myxoid connective tissue, characteristic of vocal cord nodules.

Question 34

Two patient came to see you today. One was 6 years old and the other 36. Both patients had elevated WBC counts and were complaining of hoarseness in their voice. How might the same disease present differently in these two patients?

Answer 34

This sounds like laryngeal papilloma caused by HPV 6 and HPV 11 infection (hence the elevated WBC). Although both patients present with hoarseness, you usually have multiple lesions in children and a single lesion in adults.

Question 35

A 57 year old male presents with chronic cough and stridor. He has a long history of tobacco and alcohol use. He has been previously diagnosed with HPV 6 and 11. What is your diagnosis in this patient?

Answer 35

Laryngeal carcinoma. This is a squamous cell carcinoma arising from the epithelial lining of the vocal cord. Alcohol, tobacco and laryngeal papillomas (from HPV 6 & 11 infection) all increase your risk for this cancer.

Question 36

What factors put someone at risk for pneumonia?

Answer 36

Loss of cough reflex, loss of the muco-ciliary escalator or blockade of an airway (by mucous or diseased tissue).

Question 37

What are the typical presentations of pneumonia?

Answer 37

Fever/chills (from organisms leaking into blood), cough, yellow-green (pus) or rusty (blood) sputum, tachypnea, pleuritic chest pain (bradykinin & PGE2 presence from infection), decreased breath sounds (exudate), dullness to percussion (exudate) and an elevated WBC count.

Question 38

What diagnostic tools do we use with pneumonia?

Answer 38

CXR, Sputum gram-stain & culture, blood cultures.

Question 39

A 21 year old male comes to your clinic complaining of chills, rusty sputum, pleuritic chest pain and malaise. Physical exam reveals tachypnea, a fever, decreased breath sounds over the right lung and dullness to percussion in the middle left lung. The patient's chest radiograph is seen below. What pathogen is the most common cause of pneumonia seen in this radiograph? What would you expect tissue biopsy of the lung to look like?

Answer 39

The most common causes of lobar pneumonia (note consolidation of an entire lobe) is bacterial infection. The most common types are S. pneumoniae (95%) and Klebsiella pneumoniae. Note neutrophils and exudate filling up the entirety of the alveolar air sacs.

Question 40

What pathogen is responsible for most community-acquired pneumonia cases? What demographic is most commonly affected?

Answer 40

S. pneumoniae. Middle-aged adults and elderly.

Question 41

What pathogen is responsible for most pneumonia cases in alcoholics, diabetics and malnourished patient? What is this type of pneumonia often complicated by?

Answer 41

Kelbsiella pneumoniae. This bacteria is a part of our normal flora and patients who get it are those at increased risk for aspiration (alcoholics and elderly in nursing homes). The thick mucoid capsule of this bacteria results in thick jelly sputum that has a tendency to form abscesses.

Question 42

What are the four classic phases of lobar pneumonia?

Answer 42

1) Congestion: inflammation induced by the immune response. 2) Red hepatization: neutrophils and RBCs fill the alveolar air sacs. 3) Grey hepatization: RBCs are broken down 4) Resolution: exudate is removed and alveolar air sac lining is regenerated

Question 43

A 21 year old male comes to your clinic complaining of chills, rusty sputum, pleuritic chest pain and malaise. Physical exam reveals tachypnea and a fever. The patient's chest radiograph is seen below. What pathogens are the most common causes of pneumonia seen in this radiograph? What would you expect the gross tissue of the lung to look like?

Answer 43

This patient has bronchopneumonia. Note the patchy consolidation centered around the bronchioles multi focally and bilaterally. There are many bacteria that cause this to include: staph a., H. influenzae, Pseudomonas a., Moraxella catarrhalis and Legionella p.

Question 44

What cell in the lung is responsible for making this tissue normal again?

Answer 44

This lung exhibits red hepatization after a lobar pneumonia. Type II pneumocytes are the stem cells of the lung and are responsible for making this normal again.

Question 45

A 24 year old female comes to the urgent care clinic complaining of fever, cough, chills and yellow-green sputum. History reveals a viral infection about a week ago. What pathogen is the most common offender in cases like this? What are complications associated with this pathogen?

Answer 45

Staph aureus is the most common cause of pneumonia secondary to influenza virus infection. This is because the virus knocks out the muco-ciliary escalator and allows for seeding of the bacteria. S. aureus pneumonia is often complicated by abscess or empyema (fluid in the pleural space)

Question 46

What pathogen is the most common cause of pneumonia superimposed on COPD? What other pathogen acts in this way?

Answer 46

H. influenzae. Infection will exacerbate COPD. Moraxella is associated with community-acquired pneumonia and acts in a similar way.

Question 47

What pathogen is the most common cause of pneumonia in cystic fibrosis patients?

Answer 47

Pseudomonas aeruginosa.

Question 48

What pathogen is a common cause of pneumonia superimposed on COPD that can be visualized by a silver stain? How is this pathogen normally transmitted?

Answer 48

Legionella. It is an intracellular organism and must be visualized with silver staining. The bacteria is most often transmitted by contaminated water sources to patients in immunocompromised states.

Question 49

A 28 year old female presents with a non-productive cough, low-grade fever and generalize malaise. Her chest x-ray is shown below. What type of pneumonia does this patient have? What would you expect to see on tissue biopsy of this patient's alveoli?

Answer 49

Note the diffuse interstitial infiltrates made evident by prominent lung markings in the chest x-ray. This is interstitial (atypical) pneumonia. This type of pneumonia leaves the alveoli wide open and clear, but causes inflammation in the alveolar walls as seen below.

Question 50

What bugs are associated with atypical pneumonia?

Answer 50

M. pneumoniae. C. pneumoniae. RSV. CMV. Influenza virus. Coxiella burnetii.

Question 51

A group of young military recruits all came down with low grade fevers, non-productive coughs and generalized malaise. What is the likely pathogen causing their condition and what complications come with infection by this pathogen? Why wouldn't you analyze these kids with a sputum sample and gram stain?

Answer 51

M. pneumonia often affects young adults. Complications include autoimmune hemolytic anemia (IgM against I antigen on RBCs) and erythema multiforme. Mycoplasma pneumoniae lacks a cell wall and will not show up on a gram-stain.

Question 52

A group of young military recruits all came down with low grade fevers, non-productive coughs and generalized malaise. The military is testing screening protocols and analyzes the PCR of all of these recruits. All results came back negative for mycoplasma pneumoniae. What is the likely pathogen causing their condition?

Answer 52

Chlamydia pneumoniae. It is the second most common cause of atypical pneumonia.

Question 53

What is the most common pathogen causing pneumonia in infants? Patients on post-transplant immunosuppressive therapy?

Answer 53

Infants = RSV. Post-transplant = CMV.

Question 54

What pathogen causes atypical pneumonia in elderly, immunocompromised and in patients with pre-existing lung disease? What usually contributes to mortality in patients infected with this pathogen?

Answer 54

Influenza virus. This virus increases the risk for superimposed pneumonia by S. aureus or H. influenzae infection.

Question 55

A 62 year old farmer comes to see you complaining of a non-productive cough and general malaise. He has a very high fever. Chest x-ray reveals diffuse interstitial infiltrate and prominent vascular markings. Exposure to what pathogen is likely causing the symptoms seen in this patient?

Answer 55

Coxiella spores that have been deposited on cattle by ticks or spores that are present in cattle placentas.

Question 56

How is coxiella burnetii different from other bacteria in its class?

Answer 56

It is a rickettsial organism; however, it causes pneumonia, does not require an arthropod for transmission (heat-resistant) and does not produce a skin rash.

Question 57

A 71 year old patient comes to see you. He has a history of alcoholism. He complains of a non-productive cough and generalized malaise over the past few weeks. Chest x-ray reveals a right lower lobe abscess. What pathogens are likely causing this patient's condition?

Answer 57

Alcohol use puts the patient at risk for aspiration pneumonia. The fact that there is an abscess in the right lower lobe is the prime place for aspirated materials to land. The key pathogens in aspiration pneumonia are bactericides, fusobacterium and peptococcus.

Question 58

A 25 year old male is thinking about joining the military. When doing all of his paperwork, he decides to get his immunizations done. He cannot join because he had a positive PPD. He has a history of travel to Africa for a humanitarian project. The next day he dies in a car accident and his lung biopsy is shown below. What is your diagnosis of this patient?

Answer 58

Note formation of a subpleural Ghon complex. This is indicative of primary Tb infection. With primary, Tb patients often go asymptomatic as focal caseating necrosis takes place in the lower lobe of the lung and in the hilar lymph nodes. Calcification and fibrosis of the foci forms the Ghon complex seen in this patient.

Question 59

What are common causes of secondary Tb infection? Where does this usually occur in the lung?

Answer 59

Reactivation of primary Tb with old age or AIDS (decreased immune activity). This primarily occurs in the apex of the lung.

Question 60

A 47 year old male comes to see you with complaints of fever, night sweats, hemoptysis and weight loss. He has a past medical history of HIV. Tissue biopsy is shown below. What is in your differential with this patient? How do you narrow that down?

Answer 60

Note the central caseating necrosis surrounded by histiocytes. A patient presenting with these symptoms either has secondary Tb or a fungal infection. You can do an AFB stain and look for red acid-fast bacilli, that would indicate Tb (seen below).

Question 61

How would the gross tissue look in a patient who has had reactivation of Tb for the past ten years or so?

Answer 61

The gross tissue would show caseous necrosis, miliary pulmonary Tb or tuberculous bronchopneumonia.

Question 62

When Tb spreads systemically, where does it tend to go?

Answer 62

Meninges at the base of the brain (forms granulomas), cervical lymph nodes, kidney (most common = sterile pyuria) and lumbar vertebrae.

Question 63

What is the main problem in restrictive lung diseases? What pulmonary function test values are common in patients with this type of lung disease?

Answer 63

Filling the lung. In obstructive disease, the problem is emptying the lung.

Question 64

Why is the FEV1:FVC ratio commonly increased in patients with restrictive lung disease?

Answer 64

Fibrosis often causes restrictive lung disease. Fibrosis causes thickening of the alveolar walls, increasing elastic recoil and increasing the amount of air expired in the 1st second, increasing FEV1. FVC is decreased due to decreased compliance of the lung due to fibrosis.

Question 65

What is the most common cause of restrictive lung disease? How else can you get restrictive lung disease?

Answer 65

Interstitial fibrosis. It may also arise from chest wall abnormalities (as in obesity increasing the amount of force required to open and fill the lung).

Question 66

You had a patient with restrictive lung disease characterized by progressive shortness of breath and cough. You ruled out drugs and radiation therapy as a cause, what would your diagnosis of this patient be? How do you treat this patient?

Answer 66

Idiopathic pulmonary fibrosis. Note the extremely thickened alveolar walls. This results from cyclical lung injury, cyclical lung healing, TGF-beta released by injured pneumocytes and continued fibrosis. This patient will ultimately need a lung transplant.

Question 67

What secondary causes of restrictive lung disease must you consider before arriving at the diagnosis of idiopathic pulmonary fibrosis?

Answer 67

Bleomycin, amiodarone, and radiation therapy can also cause interstitial fibrosis.

Question 68

Where does progressive fibrosis in idiopathic pulmonary fibrosis first present on a chest CT? What is it called when it progresses to the whole lung?

Answer 68

1st = subpleural region. Whole region = honeycomb lung.

Question 69

A 77 year old male presents with increasing cough and dyspnea. He has a 40 year history of working at a coal mine. What is your diagnosis?

Answer 69

Pneumoconioses. When tiny foreign particles get into the bottom of the alveoli, the macrophages consume the foreign particle and induces fibrosis all over the lung in an effort to wall off the small foreign particle. This disease requires chronic exposure to small particles that are fibrogenic.

Question 70

What are common exposures that can cause pneumoconiosis?

Answer 70

Carbon dust from coal mining (shrunken black lung), silica in sandblasters, beryllium in aerospace workers and asbestos in construction workers, plumbers and shipyard workers.

Question 71

What is Caplan syndrome?

Answer 71

Coal miner's lung associated with rheumatoid arthritis.

Question 72

What is anthracosis?

Answer 72

Build up of carbon dust in macrophages of the lung and hylar lymph nodes due to air pollution.

Question 73

Which pneumoconiosis increases your risk for Tb? Where will you find fibrotic nodules in these patients?

Answer 73

When silica gets into the macrophage it impairs formation of the phagolysosome and thus inhibits destruction of the digested body. This increases risk for Tb and causes fibrotic nodule formation in the upper lobes of the lung.

Question 74

A 52 year old male comes to see you with increased dyspnea and cough over the last two years. He has worked for NASA his whole career. Tissue analysis reveals non-caseating granulomas in the lung, hilar lymph nodes and in other systemic organs. What is your diagnosis and what is this patient at risk for?

Answer 74

Berylliosis from beryllium exposure. He is at risk for lung cancer.

Question 75

A 63 year old construction worker comes to see you complaining of increased dyspnea and chronic cough. You determine that the patient needs a lung biopsy and it is shown below. What is your diagnosis and what is the most common serious complication associated with this condition?

Answer 75

Note the long rod-shaped particle with little brown beads from iron deposition. This confirms asbestos exposure. Patients with asbestos exposure are prone to fibrosis of the lung, fibrosis of the pleura, cancer of the lung and cancer of the pleura. Specifically, patients are more likely to get lung cancer than mesothelioma (pleural cancer).

Question 76

A 32 year old African American female presents with dyspnea and cough. On physical examination you note uveitis, cutaneous nodules, decreased salivation and dry eyes. What is your diagnosis and where is this condition most commonly found in the body.

Answer 76

Note noncaseating granuloma in the lung with giant cells internally and epitheliod histiocytes surrounding it. Note the image below forming the typical asteroid body of giant cells, typical of sarcoidosis. Though granulomas are found systemically, the lung and hilar lymph nodes are most commonly affected.

Question 77

A 44 year old female presents with increasing dyspnea, cough and she can't chew a cracker and swallow it without water. Lab results reveal elevated serum ACE levels and hypercalcemia. Why might this patient's calcium levels be elevated?

Answer 77

All of these symptoms (cough, dyspnea, dryness and elevated ACE levels) point toward sarcoidosis. The patient's calcium levels are elevated because granulomas have 1-alpha-hydroxylase activity and can activate vitamin D which will increase serum calcium levels. This finding is not specific to sarcoidosis, but to any condition with non-caseating granulomas.

Question 78

How do you usually treat sarcoidosis?

Answer 78

Sometimes steroids, but the disease often resolves on its own.

Question 79

A 21 year old male presents with an acute fever, cough and dyspnea. He has been doing missionary work in central park today and symptoms began shortly thereafter. What would happen if this patient did missionary work in central park every day? What would you see on biopsy of his lung?

Answer 79

This is hypersensitivity pneumonitis, which is a reaction to an inhaled organic antigen, such as dried pigeon feces, that results in a granulomatous reaction in the lungs. Chronic exposure to the antigen will result in interstitial fibrosis. Biopsy would reveal granulomas with eosinophil infiltrate.

Question 80

What is pulmonary hypertension defined as?

Answer 80

Pressure \> 25 mmHg

Question 81

A patient is having trouble breathing when working out and he comes to see you. On auscultation of his lungs you hear bilateral rales. Tissue biopsy of his lung is shown below. What is your diagnosis and what other histological findings would you expect to see in this patient?

Answer 81

The image indicates plexiform lesions (tuft of capillaries), which are seen in long-standing pulmonary hypertension. With pulmonary hypertension you would also expect to see smooth muscle hypertrophy of the pulmonary arteries and intimal fibrosis.

Question 82

A 20 year old female comes to see you in your clinic complaining of exertional dyspnea. Phsyical exam reveals JVD and peripheral edema. What gene mutation could be contributing to the signs of heart failure you see in this young patient?

Answer 82

She has primary pulmonary hypertension possibly from inactivation of the BMPR2 gene. This causes proliferation of vascular smooth muscle and pulmonary hypertension.

Question 83

What factors may contribute to secondary pulmonary hypertension?

Answer 83

Diffuse hypoxemia (COPD or interstitial lung disease). Increased volume in pulmonary circuit (Eisenmegger's syndrome). Chronic long-standing pulmonary embolism that causes remodeling and hypertrophy of the pulmonary arteries.

Question 84

A 46 year old male comes to see you complaining of dyspnea. Physical exam reveals cyanosis in the extremities. Tissue biopsy of his lung is shown below. What is causing this patient's condition?

Answer 84

Note the formation of hyaline membranes throughout the alveoli. This is typical of ARDS because damage to the alveolar-capillary interface allows leakage of plasma proteins into the air space. These proteins are then reorganized into hyaline as they are seen on this biopsy. This ultimately results in a thicker wall for air to pass through and hypoxia. Additionally, the thicker wall has increased surface tension, causing it to close more readily and cause cyanosis.

Question 85

A 31 year old female comes to your clinic complaining of dyspnea. Physical exam reveals cyanosis in the extremities. Her chest x-ray is seen below. What cells are being damaged in this patient's condition and how do you treat her?

Answer 85

Note the diffuse white out of the lung. This is a classic finding of ARDS. Any disease that activates neutrophils and induces protease-mediated and/or free radical damage to type I and type II pneumocytes can cause ARDS. Treatment involves treating the underlying cause of pneumocyte damage and PEEP (positive end-expiratory pressure to prevent alveolar collapse).

Question 86

Why is recovery so limited in patients with ARDS?

Answer 86

The type II pneumocytes are the stem cells in the lung. If you knock those out, the only way to recover is by scar tissue formation and you get lots of interstitial fibrosis. "Repair instead of regeneration"

Question 87

A mother gives birth to a 27 week old baby. After a few hours the baby becomes tachypnic and is using accessory muscles for respiration. Shortly thereafter the baby becomes hypoxemic and cyanotic. Chest x-ray is shown below. What is causing this baby's condition and how would you treat it?

Answer 87

Note the diffuse granularity of the lung on the x-ray. This combined with the history is classic acute neonatal respiratory distress due to decreases lung surfactant and thus increased surface tension in the lung, making it harder for the baby to breath. In most neonates, lung surfactant production is not sufficient until 34 weeks.

Question 88

A mother is 34 weeks pregnant with her child and begins to see a rise in her blood pressure. The doctors suggest that they induce the baby to be safe. What test could you do to see if the baby would be able to breath when it is born?

Answer 88

L:S ratio (Lecithin : Sphingomyelin). As the lung matures, lecithin (the key ingredient in surfactant) increases and so does the ratio. When the ratio \> 2 you know the lung has reached adequate levels of surfactant production.

Question 89

What is the main ingredient of surfactant?

Answer 89

Phosphatidylcholine (also known as lecithin)

Question 90

What factors other than premature birth put a neonate at risk for acute neonatal respiratory distress?

Answer 90

C-section (unstressful delivery = no steroid release = no extra surfactant release in alveoli). Maternal diabetes (high blood sugar spills over to baby = excess insulin production by baby = insulin inhibits surfactant production)

Question 91

What complications exist for a child who is born with acute neonatal respiratory distress?

Answer 91

Persistent patent ductus arteriosus (due to poor oxygenation of lungs). Necrotizing enterocolitis (decreased oxygen going to gut). Supplemental oxygen causes increased free radical injury to the retina (causing blindness) and lungs (causing bronchopulmonary dysplasia)

Question 92

What are risk factors for lung cancer?

Answer 92

Cigarette smoke (polycyclic aromatic hydrocarbons and arsenic), radon (uranium decay in basements) and asbestos.

Question 93

A 65 year old patient presents with a cough that has lasted over 6 months. He recently started coughing up blood. His chest x-ray shows a coin lesion. What is your next step in narrowing his diagnosis?

Answer 93

A coin lesion is representative of a solitary nodule in the lung that indicates lung cancer. You would compare the nodule with previous imaging studies. If the lesion has grown, you get a biopsy. If it hasn't it's likely benign.

Question 94

A 22 year old female from Chicago comes to see you complaining of cough. CXR reveals a single coin lesion. What is the most likely cause of this lesion.

Answer 94

Histoplasmosis is a fungus that can cause granuloma formation in the lungs. It is particularly endemic in the midwest where she is from. Coin lesions in young patients usually points to a benign lesion such as this over actual lung cancer.

Question 95

How would a bronchial hamartoma present on a patient's CXR?

Answer 95

Bronchial hamartomas are benign lesions that consist of disorganized lung tissue mixed with cartilage. They are also often calcified. It would present as a coin lesion on CXR.

Question 96

You determine that a patient has a malignant coin lesion on his CXR. You biopsy the lesion and are deciding whether or not to send the patient to surgery. How will the biopsy results affect this decision?

Answer 96

If it is a non-small cell carcinoma, you will sent the patient to surgery 1st. If it is a small cell carcinoma, you will treat the patient with chemo first because these cannot be resolved w/surgical resection.

Question 97

What are the different subtypes of non-small cell carcinoma and what do you see on biopsy of these subtypes?

Answer 97

Adenocarcinoma (glands or mucus production), squamous cell carcinoma (keratin pearls or intercellular bridges), large cell carcinoma (default if not adeno or squamous) and carcinoid tumor.

Question 98

A 55 year old male smoker presents to your clinic with suspected lung cancer. You analyze the biopsy of his tumor seen below. What is your diagnosis and what associated symptoms may present in this patient?

Answer 98

Small cell carcinoma. Note the poorly differentiated small cells that look like lymphocytes and that they are mitotically active. The tumor will be located centrally in the lung. This is common in male smokers and is associated with paraneoplastic syndromes (Eaton-Lambert muscle weakness, ADH, ACTH).

Question 99

A 55 year old male smoker presents to your clinic with suspected lung cancer. You analyze the biopsy of his tumor seen below. What is your diagnosis and what associated symptoms may present in this patient?

Answer 99

Squamous cell carcinoma is the most common tumor in male smokers. It will be located centrally in the lung. Note the keratin pearls and intercellular bridges (desomosomes). It is associated with production of PTHrP production, which causes hypercalcemia.

Question 100

A 55 year old female smoker presents to your clinic with suspected lung cancer. You analyze the biopsy of her tumor seen below. What is your diagnosis and what associated symptoms may present in this patient?

Answer 100

Adenocarcinoma. This is the most common lung tumor in female smokers and in non-smokers. Note the gland-forming, mucin producing cells in the biopsy. These tumors usually manifest in the periphery of the lung.

Question 101

A 60 year old male comes to see you in the clinic due to suspected lung cancer. He has a 35 pack year history of smoking. Biopsy of his lesion showed large cells and did not reveal any keratin pearls, intercellular bridges, glands or mucin. What is your diagnosis?

Answer 101

Large cell carcinoma. Absence of the other main lung cancers tips the scale towards this cancer.

Question 102

A 49 year old female comes to see you in clinic due to suspected lung cancer. She has no history of smoking and it appears that the lesion is on the periphery of her lungs. CXR reveals pneumonia-like consolidation. Her biopsy is shown below. What is your diagnosis?

Answer 102

Bronchioloalveolar carcinoma. This is when columnar cells from Clara cells grow along the bronchioles and alveoli. This condition has a very good prognosis.

Question 103

How does carcinoid tumor (seen below) differ from small cell carcinoma of the lung?

Answer 103

Carcinoid tumors are well-differentiated neuroendocrine tumors where small cell is poorly differentiated. They would both stain positive for chromogranin (shown below) because they are both neuroendocrine cells. Carcinoid is not related to smoking where small cell is. Small cell is located centrally where carcinoid tumors form a poly-like mass in the bronchus (seen below). Carcinoid tumors are also a low-grade malignancy.

Question 104

If you suspect someone has lung cancer, what is the most likely lesion you will observe on CXR?

Answer 104

Multiple "cannon-ball" nodules. Metastasis to the lung from the breast and colon are more common than primary lung tumors and present in this manner.

Question 105

Where is the lung's favorite place to metastasize?

Answer 105

Adrenal gland.

Question 106

Why does lung cancer have such a poor prognosis?

Answer 106

Poor screening methods and it presents at a later and more advanced stage.

Question 107

What local complications can occur with lung cancer?

Answer 107

Pleural involvement (especially adenocarcinoma), SVC obstruction (JVD, edema & cyanosis), hoarseness (recurrent laryngeal nerve), diaphragmatic paralysis (phrenic nerve), ptosis, pinpoint pupil and anhidrosis (all from compression of the sympathetic chain).

Question 108

Which way does the trachea shift in a patient who had a spontaneous pneumothorax from a congenital bleb?

Answer 108

Toward the side of the pneumothorax.

Question 109

Which way does the trachea shift in a patient who had a tension pneumothorax?

Answer 109

Away from the injury.

Question 110

How would you expect a mesothelioma to present?

Answer 110

Occupational exposure to asbestos, pleural effusions (hyperactive mesothelial cells), dyspnea and chest pain.

Question 111

How would a mesothelioma look on a gross section?

Answer 111

It encases the entire lung.