L61 Flashcards
Name the 3 main types of lung cancers
Small cell
Non-small cell:
- Squamous cell
- Adenocarcinoma (most likely to get this if a non-smoker)
What are the 2 genetic targets commonly mutated in adenocarcinoma?
EGFR
EML4-ALK
Impt to note b/c therapy targets. Other lung cancers are too diverse in the causative mutations to be targeted
What is the precursor lesion for:
Adenocarcinoma in situ
Small cell
Atypical adenomatous hyperplasia = AAH (non-invasive) -> in situ (non-invasive) -> invasive
*No in situ lesion for small cell cancers b/c too aggressive to have a precursor lesion
Adenocarcinoma
- Describe the cells
- Cell markers expressed
Neoplasic cells are glandular (acinar pattern) or mucin producing (or both)
TTF-1 = thyroid transcription factor
- Not used as treatment target, only for dx
Describe the most prevalent growth patterns of adenocarcinoma
**Peripheral
Can also be:
- Central (arising from bronchus)
- Pna-like = filling air spaces (grows along alveolar walls)
If an adenocarcinoma is invasive, what are the 5 histo patterns it can form?
Acinar - glands Papillary Mucinous Solid - since solid adenos are so uncommon, you must make sure these tumors either make mucin or are TTF 1 + Micropapillary
Adenocarcinoma in situ has no risk for mets b/c non-invasive. What is this tumor’s:
- Spread
- 2 subtypes
Lepidic spread - tumor cells like scales on alveolar septa
1. Mucinous - more likely to have invasive component
Vs
2. Non-mucinous
When you say adenocarcinoma in situ is multifocal, what does that mean?
- Aerogenous spread - mucinous subtype likely to fill alveolar spaces and look more like pna
- Field effect = pre-cancerous AAH involves a lot of the lung so multiple in situ tumors occur
What kind of tumor is a bronchioloalveolar carcinoma?
- Mucinous vs non
Adenocarcinoma in situ
- Mucinous = lepidic growth pattern
- Non-mucinous = spreads along alveolar surfaces
If you see ground glass appearance on CT in a confined lesion, which of these is on your differential:
- AAH
- Adenocarcinoma in situ
- Invasive adenocarcinoma
1 & 2 b/c confined lesion = non-invasive
Do you need to be able to tell AAH from adenocarcinoma in situ on histo?
NO
Squamous carcinoma
- Central or peripheral?
- Describe tumor characteristic
Central - might fill airway
Cavitary
3 main features of squamous carcinoma on histo
- Solid tumor - “pavement like” with cells that have lots of cytoplasm
- Keratin pearls
- Intercellular bridges = desmosomes on cancer cells
What are the squamous cell precursor lesions
**Remember, normally there is no squamous epithelium in the resp tract - so this is more often a response to injury (smoking)
Squamous metaplasia
Squamous dysplasia - some malignant characteristics
Squamous in situ - malignant except for hasn’t invaded yet: irregular nuclei, varying cell size
Invasive
A peripheral nodule is most likely what type of lung cancer?
Adenocarcinoma
How treat small cell carcinoma: surg or chemo or both?
Chemo not surg
Small cell carcinoma - peripheral or central?
Central
** Think: the smoking cancers are more likely to be central b/c that is where smoke would hit first when inhaled
4 major attributes of small cell carcinoma on histo
- Endocrine differentiation
- Neurosecretory granules: synaptophysin & chromogranin - Small cells that are mostly nucleus w/o nucleoli (why stain blue) = salt and pepper
- High mitotic rate
- Necrosis common
What are the 4 neuroendocrine tumors of the lung?
Typical carcinoid
Small cell
Atypical carcinoid
Large cell
Describe the appearance of carcinoid tumor on histo, What’s different about atypical carcinoid?
Look like small blue cell tumors but not as high grade - more likely to be benign
- Lots of cytoplasm
- Uniform nuclei
Atypical is more intermediate behavior - more mitotic figures, less likely for 10 year survival
Describe the typical carcinoid pt
Young (
Carcinoid:
- Central vs peripheral
- In what tissue layer
- Hetero or homogenous
Central but may also be peripheral
Submucosal - under resp epi
Homogenous - no necrosis or cavitation
Will carcinoid tumors stain for chromogranin or synaptophysin?
YES - neuroendocrine tumors
What is carcinoid syndrome?
Carcinoids in the gut or met to the liver increase vasoactive amines Symptoms: - Diarrhea - Flushing - Cyanosis
