Flashcards in Ch 12: Pneumoconioses and Interstitial Lung Diseases Deck (18)
Your alternate career (if BAP prevents you from becoming a physician) puts you at risk for some occupational hazards. As some of the smaller materials you are inhaling reach the acini of your respiratory tract, what restrictive process does this stimulate? What are these general disorders called?
Fibrosis, which is the key factor in the genesis of symptomatic pneumoconioses. As alveolar macrophages engulf these foreing particles, fibrosis is induced.
Your 45 year old male patient works as a sand blaster, exposing him to plenty of silica. Based on his history, you suspect him to have a restrictive lung disease. If you ordered a biopsy, what would the histological appearance appearance of his condition be? What other respiratory illness is your patient at risk for?
Histologically would see characteristic whorled appearance of fibrotic pulmonary nodules. There is a high association between silicosis and development of TB.
What are the different forms of silicosis? What would each of them look like histologically or radiographically?
Simple nodular: whorled appearance, fibrotic nodules. Can see "eggshell calcification" of hilar nodes
Progressive massive: masses greater than 2 cm in diameter on imaging. show central cavitation
Acute silicosis: uncommon, but shows diffuse fibrosis. Appearance with eosinophilic material mimcs alveolar lipoproteinosis (called silicoproteinosis)
What is the main difference (besides innocuous particle) between silicosis and anthracosilicosis? What are the different classifications of anthracosilicosis? What autoimmune disease is related to this and other pneumoconioses?
Main difference is the development of an innocuous anthracosis (coal worker's pneumoconiosis or CWP) vs a highly fibrogenic process in silicosis. Though massive exposure can lead to diffuse fibrosis (black lung)
Simple CWP: non palpable coal dust macules and palpable coal dust nodules, formed by many carbon laden macrophages. Causes minor lung impairment
Complicated CWP: progresses from simple CWP, if lesion is 2 cm or greater.
Caplan nodules: large nodules in lungs of some pneumoconioses patients that have RA
As a pathologist, you are analyzing a slide of an alveoli and notice thin golden fibers surrounded by a beaded iron protein coat. What pneumoconiosis does this finding represent? What is the pathogenesis of interstitial fibrosis in this disease? What are such patients at risk for developing?
These are "asbestos bodies," that are often engulfed by alveolar macrophages. Activated macrophages release inflammatory meidators that promote fibrogenic properties of asbestor fibers. Asbestosis patients are at risk for development of fibrosis of the lung and pleura, and cancer of the lung (carcinoma) and pleura (mesothelioma). Also at risk for rounded atelectasis
What are some gross and histological characteristics of a key finding seen in asbestosis?
Patients may also have pleural effusion, and smooth, pearly white, nodular plaques. These pleural plaques consist of acellular, dense, hyalinized fibrous tissue, in a "basket weave pattern."
Your 22 year old male patient is going through his identity crisis and can't decide what he wants to do with his life! He first ventures into aerospace engineering, and then gets bored of making spaceships and spends some time in the textile industry (and while there got into some bad habits with some bad peeps and started using heroin). What two pneumoconioses are associated with each of these two career (and recreational activity) choices? Tell me briefly about each disease?
Berylliosis is associated with workers in the aerospace, industrial ceramic, and nuclear industries. This presents with noncaseating granulomas (similar to sarcoidosis!), and is associated with increased risk for lung cancer.
Talcosis is from prolonged talc exposure from the leather, rubbber, paper, and textile industries, or with IV drug abusers who use talc as a carrier for their drug. This can vary from tiny nodules in the lung to severe fibrosis.
What is the pathogenesis of hypersensitivity pneumonitis, and what do you see histologically? What type of hypersensitivity reaction is it?
This is a caseating or noncaseating granulomatous reaction after inhalation of an unknown antigen. Histologically, most cases have serum IgG antibodies against the antigen, with a T cell response of mostly CD8+ cells.
It is a combined type III and IV hypersensitivity reaction.
(FYI, discrepancy here with pathoma. Dr. Sattar says many eosinophils present, which makes sense bc it is hypersensitivity. But Rubin's says eosinophils uncommon.)
An African American female patient is found to have noncaseasting granulomas in the lungs, with a high proportion of CD4+:CD8+ T cells. What histological finding is characteristic of this pathology and other granulomatous processes? What are laboratory identifiers to help you Dx this condition, since there is no specific lab test?
This patient has sarcoidosis, classically seen in African American females. There is no known mechanism for the pathogenesis, but increased CD4:CD8 response is thought to be involved. Asteroid bodies and schaumman bodies within the giant cells of granulomas are seen, but not specific for sarcoidosis.
ACE levels are usually elevated, as well as calcium levels (due to increased 1-alpha hydroxylase activity in granuloma histiocytes converting vitamin D to its active form)
What is the relationship between usual interstitial pneumonia (UIP) and idiopathic pulmonary fibrosis? What other conditions are IPF and UIP associated with? What is the histological hallmark of UIP?
UIP is one of the most common causes of interstitial pneumonia (hence the "usual" in the name). IPF is applied to interstitial pneumonia when the origin of the disease is unknown.
IPF is associated with genetic influences, and UIP with collagen vascular diseases (RA, lupus, etc), chronic hypersensitivity pneumonitis, drug toxicity, and autoimmune disorders.
UIP shows patchy interstitial fibrosis, with areas of normal lung adjacent to fibrosis. The fibrosis is of different ages, which is called "temporal heterogeneity."
On physical exam it is common to find late inspiratory crackles and fine "velcro" rales at the lung base
What are the two forms of nonspecific interstitial pneumonia? What is the common CT finding?
Cellular form: lymphocytic infiltrate
Fibrosing form: septa show diffuse fibrosis
CT shows bilateral lower lobe "ground glass" changes or reticulation (net forming pattern) with traction bronchiectasis.
What does the term "honeycomb lung" refer to?
This is a description of diffuse fibrosis seen in end stage disease
What is the main contrasting feature of desquamative interstitial pneumonia and respiratory bronchiolitis? What patients are usually affected?
DIP is a diffuse lung disease, whereas RB is characterized by patchy lesions. Both of these conditions are commonly seen in smokers.
DIP has prominent hyperplasia of type II pneumocytes. And PRESERVATION OF LUNG ARCHITECTURE
If a pneumonia developed polypoid plugs in the bronchiolar lumen and surrounding alveoli, therefore occluding bronchioles and alveolar ducts, what would this be called (there are a few names)?
Organizing pneumonia patter
Cryptogenic organizing pneumonia
BOOP: bronchiolitis obliterans-organizing pneumonia
patchy areas of loose organizing fibrosis occlude the smaller air spaces, created "plugs" in the lumen
Your HIV+ patient is found to have diffuse infiltration of the alveolar septa by lymphoid and inflammatory cells. What is this condition, and what others it is associated with?
This is lymphoid interstitial pneumonia, and it often occurs in the setting of autoimmune diseases. It is also seen in HIV patients.
Sarcoid like, non caseating granulomas are often seen
A biopsy shows scattered nodular infiltrates with a stellate border, extending into the surrounding pulmonary interstitium. There are also marked eosinophils present. What is this condition?
Langerhans cell histiocytosis.
FYI: Distinct characteristics of Langerhans cells:
Birbeck granules, C3, IgG-Fc receptors, CD1a, HLA-DR, S100 expression.
What interstitial lung disease is characterized by abnormal proliferation of smooth muscle? What are some common findings on CXR and biopsy? What immunostain can specifically identify these abnormal smooth muscle cells? How do you treat this disease and why do you use this treatment?
Common findings: hyperinflation of the lung and pleural effusion.
Immunostaining: HMB-45 specifically identifies LAM cells but not other lung smooth muscle cells.
Treatment: Hormonal ablation therapy, since LAM cells usually express estrogen or progesterone receptors.