Lung Pathology

Question 1

What gene encodes p16

Answer 1

CDKN2A

Question 2

Is lung SqCC or adenocarcinoma most strongly associated with cigarette smoking

Answer 2

Squamous cell

Question 3

What percentage of lung adenocarcinoma in caucasians are EGFR mutant. What group is higher than this

Answer 3

10-15%
Asian women

Question 4

What percentage of lung adenocarcinoma have KRAS mutation

Answer 4

30%

Question 5

How commonly is small cell lung cancer smoking associated

Answer 5

Almost always

Question 6

What major tumour suppressor proteins are almost always mutated in small cell lung cancer

Answer 6

Rb, p53.

Question 7

Where are SqCC vs adenoCa more likely to be located in the lung

Answer 7

Peripheral; adenocarcinoma
Central; SqCC

Question 8

What is a lepidocrocite pattern of spread? Which type of lung cancer shows this pattern?

Answer 8

Tumour cells appearing to crawl along normal spaces, in this case alveolar septa. Common in adenocarcinoma.

Question 9

What subtypes of lung adenocarcinoma tends to form satellite lesions

Answer 9

Mucinous adenocarcinoma. Therefore less likely cured with surgery.

Question 10

What are pathological features that are required for diagnosis of large cell lung cancer

Answer 10

Diagnosis of exclusion. Negative TTF-1, p40 (and others).

Question 11

What are common neurological consequences of pancoast tumours

Answer 11

Horners syndrome
Pain in distribution of ulnar nerve

Question 12

What are the most common sites of metastasis of lung cancer at initial diagnosis

Answer 12

Adrenal (>50%)
Liver 30-50%
Brain 20%
Bone 20%

Question 13

What does an activating mutation of KRAS mean prognostically in the absence of treatment

Answer 13

Worse prognosis

Question 14

What are the non-carcinoma neuroendocrine tumours of the lung, and how are they classified

Answer 14

Carcinoid.
-Typical: less than 2 mitosis per 10 high power field
-atypical 2-10 mitosis.

Question 15

What is the classical carcinoid syndrome

Answer 15

Intermittent:
Diarrhoea
Flushing
Cyanosis

Question 16

What are the most common anterior mediastinal tumours (6)

Answer 16

Thymoma
Teratoma
Lymphoma
Thyroid
Parathyroid
Metastatic carcinoma
Robbins pg 724

Question 17

What are the most common posterior mediastinal tumours

Answer 17

Lymphoma
Metastatic (usually lung)
Neurogenic (schwannoma, neurofibromas)
Bronchogenic cyst
Gastrointestinal hernia

Question 18

What is a commonly benign pleural tumour. What are it’s morphological features

Answer 18

Solitary fibrous tumour
-dense fibrous tissue, interspersed spindle cells resembling fibroblasts
-CD34+, STAT6+, keratin- (opposite of mesothelioma)
-rarely malignant; pleomorphism, mitotic activity, necrosis, large size >10cm

Question 19

What tumour suppressor gene is lost in 80% of mesothelioma

Answer 19

CDKN2A (p16)

Question 20

What is the lifetime risk of mesothelioma in individuals heavily exposed to aspestos

Answer 20

7-10%

Question 21

Morphologically what are the two main subtypes of mesothelioma

Answer 21

Epithelioid
Sarcomatoid

Question 22

What is the common immunohistochemistry profile for mesothelioma

Answer 22

Keratin proteins
WT-1+
Calretinin+
Cytokeratin 5/6+
Claudin4-
Sarcomatoid subtype less commonly has this profile

Question 23

Which immunotherapy drugs target PD-1

Answer 23

Pembbrolizumab
Nivolumab

Question 24

Which immunotherapy drugs target PD-L1

Answer 24

Durvalumab
Atezolizumab

Question 25

What is the difference between PD-1 and PD-L1

Answer 25

PD-L1 is what tumour cells can express to interact with PD-1 on immune T-cells to stop the immune cell killing the cancer cell

Question 26

What are the 5 histological patterns of lung adenocarcinoma, and what grade is each associated with

Answer 26

LAMPS Low: Lepidic Intermediate: papillary, acinar High: micropapillary, solid

Question 27

What is the definition of lung adenocarcinoma in situ

Answer 27

Lesion <3cm No invasion Usually lepidic pattern

Question 28

Is lung adenocarcinoma or SqCC more likely to metastasise. What are the most common sites

Answer 28

Adenocarcinoma more likely Brain>bone>liver>adrenal

Question 29

How are EGFR point mutations tested for in lung cancer

Answer 29

PCR/ NGS

Question 30

How is ALK mutation tested for in lung cancer

Answer 30

Abnormality is generally rearrangement Initial IHC for over expression Confirmation with FISH

Question 31

What are the criteria for invasion of lung adenocarcinoma

Answer 31

1) Histological pattern other than lepidic 2) desmoplastic stroma 3) pNI or LVI 4) spread through air spaces

Question 32

What is the IHC pattern of mucinous adenocarcinoma of the lung

Answer 32

CK7+ CK20 +/- TTF1 +/- CDX2 +/-

Question 33

What is the prognosis of mucinous lung adenocarcinoma in comparison to other adenocarcinoma types

Answer 33

Worse prognosis

Question 34

What is the microscopic appearance of lung mucinous adenocarcinoma

Answer 34

Goblet or columnar cells Abundant intracellular mucin Cytologically bland

Question 35

What is the parthenogenesis of lung SqCC

Answer 35

Irritant/ carcinogen exposure Hyperplasia Squamous metaplasia Squamous dysplasia SqCC in situ SqCC

Question 36

What should be stained when assessing for pleural invasion

Answer 36

Elastin (EVG)

Question 37

What are examples of mesynchymal tumours that can arise in the lung

Answer 37

Hamartoma PEComa Solitary fibrous tumour