Lung neoplasms

Question 1

What is a hamartoma?

Answer 1

It is a disorganized admixture of cells indiginous to that site. Includes, blood vessels, glands, cartilage, smooth muscle, inflammatory cells, fat, etc in various proportions

Question 2

Radiographically, what is a hamartoma of the lung called?

Answer 2

Coin lesion

Question 3

Describe a lung hamartoma macroscopically

Answer 3

It is a well-circumscribed spherical small mass (1-4cm). It is a discrete lesion with yellowish pale cut surface. Often has calcifications recognizable on radiography.

Question 4

What is a choristoma?

Answer 4

It is a mass composed of normal tissues but in an ectopic location. EG pancreatic islets in liver or stomach.

Question 5

Usually what causes a hamartoma?

Answer 5

It is caused by clonal expansion of cells with 6p21 or 12q14
q15 chromosomal alterations

Question 6

What is the differential diagnoses for hamartoma?

Answer 6

The differential diagnosis includes granuloma,
small primary carcinoma, solitary metastasis, or
hamartoma

Question 7

Microscopically, what does a pulmonary hamartoma look like?

Answer 7

cartilage that is jumbled with a fibrovascular stroma and scattered bronchial
glandular structures

Question 8

T/F Most lung tumors are benign. Explain

Answer 8

F they are malignant
metastatic tumors are the most common lung carcinoma seen in clinical
practice

Question 9

What is Atypical adenomatous hyperplasia (AAH)?

Answer 9

It is a small (<5mm) lesion characterised by dysplastic pneumocytes lining alveolar wall that are midly fibrotic

Question 10

What is adenocarcinoma in situ (AIS)?

Answer 10

A lesion 3cm or less composed of cells that are entirely dysplastic, growing along peexisting alveolar septa without rapturing it. Has a lepidic growth pattern

Question 11

when the AIS becomes invasive, it forms what?

Answer 11

It forms desmoplasia (fibrosis)

Question 12

What is a minimally invasive adenocarcinoma (MIA)?

Answer 12

<3cm lesion. It is a solitary adenocarcinoma with either pure lepidic growth or predominant lepidic growth with <5cm of stromal invasion

Question 13

List the 3 precursor lesions associated with adenocarcinoma

Answer 13

1. Atypical adenomatous hyperplasia (AAH)
2. Adenocarcinoma in situ (AIS)
3. Minimally invasive adenocarcinoma (MIA)

Question 14

What is a bronchoalveolar carcinoma?

Answer 14

It is a subtype of adenocarcinoma. But this type does not have any stromal, vascular, or pleural invasion. The tumor grows along thr pre-existing alveolar septa

Question 15

Broncheoalveolar carcinoma has which type of spread?

Answer 15

It has an aerogenous spread. It does not have metastatic spread

Question 16

What is the common cause of death for bronchoalveolar carcinoma?

Answer 16

Due to involvement of the airways,
the patient usually dies by suffocation

Question 17

What are the clinical features of bronchoalveolar carcinoma? (7)

Answer 17

Cough
Weight loss
Dyspnoea
Anorexia
Fatigue
Hemoptysis
Chest pain

Question 18

Describe the metastatic pattern of bronchoalveolar carcinoma

Answer 18

Metastasis of the cancer causes involvement of adrenal (most commonly) followed by liver, brain and bone.
Intrathoracic spread of the cancer causes enlargement of lymph nodes (hilar, mediastinal, bronchial and
tracheal), pleural involvement,
hoarseness (recurrent laryngeal nerve invasion),
dysphagia (esophageal obstruction),
diaphragmatic paralysis (phrenic nerve paralysis),
Horner syndrome and
superior vena cava (SVC) syndrome

Question 19

List 5 endocrinological syndromes associated with bronchogenic cancer, and their causes

Answer 19

a. Cushing syndrome (Due to ACTH)
b. Syndrome of inappropriate ADH secretion (SIADH) [Due to anti-diuretic hormone]
c. Hypercalcemia: Due to parathyroid hormone related peptide (PTH related peptide).
d. Hypocalcemia: Due to calcitonin
e. Gynecomastia: Due to gonadotropins

Question 20

Which paraneoplastic syndrome is caused by autoantibodies against neuronal calcium channel?

Answer 20

Lambert eaton syndrome

Question 21

Which paraneoplastic syndrome is causes hyperpigmentation of the axillary region?

Answer 21

Acanthosis nigrans

Question 22

Explain the pathogenesis of bronchogenic cancer

Answer 22

1.Stepwise accumulation Oncogenic driver mutations causes neoplastic transformation of epithelial cells

Question 23

What are the subdivisions of bronchogenic cancer?

Answer 23

Commonly divided into non-small cell (including adenocarcinoma, squamous cell carcinoma, other types) and small cell
carcinoma based on behaviour and prognosis.

Question 24

Pathogenesis of adenocarcinoma

Answer 24

Most common type in never-smokers, although it is also associated to a lesser extent with smoking. A third
of adenocarcinomas have oncogenic gain-of-function mutations involving growth factor receptor signalling pathways that can
be targeted by specific inhibitors e.g. tyrosine kinase receptors (EGFR, ALK, ROS1) or their downstream molecules (KRAS –
usually in smokers)

Question 25

Pathogenesis of squamous cell carcinoma

Answer 25

Highly associated with smoking and has diverse genetic aberrations. Most haveTP53 mutations, often as an early event, and may also have FGFR1 amplification

Question 26

Small cell carcinoma pathogenesis

Answer 26

: Almost always smoking-related and the highest mutational burden, with inactivation of both TP53 and RB. May also have MYC amplification* Precursor lesions: There are morphologic precursor epithelial lesions which do not necessarily all progress to cancer

Question 27

Describe Small cell carcinoma (Poorly differentiated neuroendocrine/ Oat cell

Answer 27

Aggressive, highly malignant, tumour . * Poor prognosis : due to late presentation , usually demonstrates metastasis at initial presentation Least likely to be cured by surgery * Associated with cigarette smoking 95% of patients (unlike adenocarcinoma) * Common in men

Question 28

How does small cell carcinoma present?

Answer 28

Present as hilar or perihilar mass

Question 29

Which paraneoplastic syndromes can be associated with small cell carcinoma?

Answer 29

Has ability to secrete a host of polypeptide hormones such as ACTH (adrenocorticotropic hormone) , ADH (antidiuretic hormone). * It may associated with Paraneoplastic Syndrome , Cushing syndrome , Eaton- Lambert syndrome] These phenomena are mediated by humoral factors (by hormones or cytokines) secreted by tumor cells or by an immune response against the tumor

Question 30

Explain superior vena cava syndrome

Answer 30

: invasion leads to obstruction of venous drainage which leads to dilation of veins in the upper part of the chest and neck resulting in swelling and cyanosis of the face, neck, and arms.

Question 31

What is a pancoast tumor (superior sulcus tumor)?

Answer 31

Apical (upper lobe) Bronchogenic carcinoma (could be either squamous or adenocarcinoma) neoplasms may invade the brachial sympathetic plexus to cause severe pain, numbness and weakness in the distribution of the ulnar nerve. Accompanied by destruction of the first and second ribs and thoracic vertebrae. It often coexists with Horner syndrome (ptosis + asymmetrical miosis + anhidrosis)

Question 32

What is Horner syndrome?

Answer 32

invasion of the cervical thoracic sympathetic nerves and it leads to ipsilateral enophthalmos (displacement of the eyeball within the orbit –eyes goes inside-). miosis, ptosis, and facial anhidrosis. (Anhidrosis is the inability to sweat normally –leads to dryness in –leads to dryness in facial areas-). The combination of these clinical findings is known as Pancoast syndrome.

Question 33

Where are pancoast tumors normally located?

Answer 33

primary bronchus or at the lung periphery

Question 34

Describe carcinoid tumor appearance

Answer 34

The tumour is a smooth surfaced yellow nodule. * Histologically these resemble carcinoid tumours of the appendix. A small proportion of these tumours metastasise to regional lymph nodes – all are potentially malignant

Question 35

Central tumours tend to block the bronchus in which they arise RESULTING IN....? (5)

Answer 35

Obstruction * Collapse of lung. * Pneumonia Infection * Bronchiectasis * Lung abscess

Question 36

Which tumor shows nuclear pleomorphism, mitotic activity and necrosis. Over half eventually metastasised

Answer 36

Atypical carcinoid tumors