Lung Pathology Flashcards
What gene encodes p16
CDKN2A
Is lung SqCC or adenocarcinoma most strongly associated with cigarette smoking
Squamous cell
What percentage of lung adenocarcinoma in caucasians are EGFR mutant. What group is higher than this
10-15%
Asian women
What percentage of lung adenocarcinoma have KRAS mutation
30%
How commonly is small cell lung cancer smoking associated
Almost always
What major tumour suppressor proteins are almost always mutated in small cell lung cancer
Rb, p53.
Where are SqCC vs adenoCa more likely to be located in the lung
Peripheral; adenocarcinoma
Central; SqCC
What is a lepidocrocite pattern of spread? Which type of lung cancer shows this pattern?
Tumour cells appearing to crawl along normal spaces, in this case alveolar septa. Common in adenocarcinoma.
What subtypes of lung adenocarcinoma tends to form satellite lesions
Mucinous adenocarcinoma. Therefore less likely cured with surgery.
What are pathological features that are required for diagnosis of large cell lung cancer
Diagnosis of exclusion. Negative TTF-1, p40 (and others).
What are common neurological consequences of pancoast tumours
Horners syndrome
Pain in distribution of ulnar nerve
What are the most common sites of metastasis of lung cancer at initial diagnosis
Adrenal (>50%)
Liver 30-50%
Brain 20%
Bone 20%
What does an activating mutation of KRAS mean prognostically in the absence of treatment
Worse prognosis
What are the non-carcinoma neuroendocrine tumours of the lung, and how are they classified
Carcinoid.
-Typical: less than 2 mitosis per 10 high power field
-atypical 2-10 mitosis.
What is the classical carcinoid syndrome
Intermittent:
Diarrhoea
Flushing
Cyanosis
What are the most common anterior mediastinal tumours (6)
Thymoma
Teratoma
Lymphoma
Thyroid
Parathyroid
Metastatic carcinoma
Robbins pg 724
What are the most common posterior mediastinal tumours
Lymphoma
Metastatic (usually lung)
Neurogenic (schwannoma, neurofibromas)
Bronchogenic cyst
Gastrointestinal hernia
What is a commonly benign pleural tumour. What are it’s morphological features
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
What tumour suppressor gene is lost in 80% of mesothelioma
CDKN2A (p16)
What is the lifetime risk of mesothelioma in individuals heavily exposed to aspestos
7-10%
Morphologically what are the two main subtypes of mesothelioma
Epithelioid
Sarcomatoid
What is the common immunohistochemistry profile for mesothelioma
Keratin proteins
WT-1+
Calretinin+
Cytokeratin 5/6+
Claudin4-
Sarcomatoid subtype less commonly has this profile
Which immunotherapy drugs target PD-1
Pembbrolizumab
Nivolumab
Which immunotherapy drugs target PD-L1
Durvalumab
Atezolizumab
What is the difference between PD-1 and PD-L1
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
What are the 5 histological patterns of lung adenocarcinoma, and what grade is each associated with
LAMPS
Low: Lepidic
Intermediate: papillary, acinar
High: micropapillary, solid
What is the definition of lung adenocarcinoma in situ
Lesion <3cm
No invasion
Usually lepidic pattern
Is lung adenocarcinoma or SqCC more likely to metastasise. What are the most common sites
Adenocarcinoma more likely
Brain>bone>liver>adrenal
How are EGFR point mutations tested for in lung cancer
PCR/ NGS
How is ALK mutation tested for in lung cancer
Abnormality is generally rearrangement
Initial IHC for over expression
Confirmation with FISH
What are the criteria for invasion of lung adenocarcinoma
1) Histological pattern other than lepidic
2) desmoplastic stroma
3) pNI or LVI
4) spread through air spaces
What is the IHC pattern of mucinous adenocarcinoma of the lung
CK7+
CK20 +/-
TTF1 +/-
CDX2 +/-
What is the prognosis of mucinous lung adenocarcinoma in comparison to other adenocarcinoma types
Worse prognosis
What is the microscopic appearance of lung mucinous adenocarcinoma
Goblet or columnar cells
Abundant intracellular mucin
Cytologically bland
What is the parthenogenesis of lung SqCC
Irritant/ carcinogen exposure
Hyperplasia
Squamous metaplasia
Squamous dysplasia
SqCC in situ
SqCC
What should be stained when assessing for pleural invasion
Elastin (EVG)
What are examples of mesynchymal tumours that can arise in the lung
Hamartoma
PEComa
Solitary fibrous tumour
