Pulmonary Pathology 5 Flashcards
carcinogen exposure may be mitigated by genetic variation such as what?
P450 polymorphisms and genes responsible for DNA repair
what is the most common type of lung cancer?
adenocarcinoma
what is the second most common type of lung cancer?
squamous cell carcinoma
what cells do squamous cell carcinomas arise from?
basal cells
what cells do small-cell carcinomas arise from?
neuroendocrine cells
what cell does adenocarcinomas arise from?
type II alveolar cells
which types of lung cancer are heavily linked with smoking?
squamous cell carcinoma and small cell carcinomas
how does a neuroendocrine cell become small cell carcinoma?
p53 inactivations
which type of cancer is most likely to be found in non-smokers?
adenocarcinoma
how does adenocarcinoma develop?
normal–> atypical adenoma hyperplasia–> adenoma in situ–> adenocarcinoma
how is atypical adenomatous hyperplasia (AAH) defined?
less than 5mm (if it gets any bigger then it is considered to be AIS); dysplastic pneumocytes present along alveoli with some interstitial fibrosis
how is adenocarcinoma in situ defined?
less than 3 cm (must be under 3 cms); dysplastic pneumocytes confluently growing along the alveoli
how does pulmonary adenocarcinoma arise?
either from precursors or it develops de novo
what does histology of pulmonary adenocarcinoma show?
malignant glands invading the lung tissue
what is a test used for pulmonary adenocarcinoma?
TTF staining (thyroid-transcription fator-1)
what is mucinous adenocarcinoma?
a variant of pulmonary adenocarcinoma; it is not in situ because it extends to far, but it is not invading; very deadly
what does the progression of normal bronchial epithelium require in order to progress to squamous carcinoma?
metaplasia
what is the progression of normal bronchial epithelium to squamous carcinoma?
normal–> squamous metaplasia–> squamous carcinoma in situ (dysplasia)–> invasive squamous carcinoma
how do you recognize squamous carcinoma on histology?
keratin pearls
how do you recognize squamous carcinoma on cytology?
orange cytoplasm= keratin
what are the characteristic features of squamous carcinoma?
more common in men, strong association with smoking, often occurs centrally
which lung cancer is almost always associated with smoking?
small cell neuroendocrine carcinoma
how does small cell neuroendocrine carcinoma appear histologically?
small cells with fine blue nuclear chromatin, scant cytoplasm, nuclear “molding”, and characteristic necrosis
how do you treat adenocarcinomas?
on the basis of molecular testing: EGFR, ALK, or PDL-1
so when you know that an adenocarcinoma shows EGFR over expression, what do you do?
you know that that EGFR is driving the malignant function- so block it with erlotinib
what is there is inversion of that area chromosome 2p where we find our ALK gene?
there may be a fusion protein there that sends the cell cycle into over drive/ proliferation; so you block it by using crizotinib
what is the general flow chart for adenocarcinoma therapy?
look for an EGFR mutation, if it is positive you treat it with an EGFR TKI; if it is negative you look for an ALK rearrangement; if that is positive you treat with crizotinib
what should you not use when treating squamous carcinoma?
VEGF inhibitors (these tumors are very sensitive to bleeding)
what paraneoplastic syndrome is associated with squamous carcinoma?
PTH-rP hypercalcemia
what paraneoplastic syndrome is associated with small cell carcinoma?
SIADH (syndrome of inappropriate ADH secretion) and Cushing’s syndrome (secretion of ACTH)
what may be the primary manifestation of the paraneoplastic syndromes?
electrolyte disturbances and/or mental status changes
what makes up Horner’s syndrome?
enophthalmos (sunken eyeball), ptosis, miosis (small pupil), anhidrosis; aka oculosympathetic palsy
horner’s syndrome can occur at many sites along the sympathetic pathway; how can you localize it to the thoracic outlet?
if the patient is present with brachial plexus symptoms–> wasting, pain, paresthesias, and paresis of arm and hand
what are the stages of neuroendocrine tumors?
DIPNECH, carcinoid tumor, atypical carcinoid tumor, small cell neuroendocrine carcinoma
what does DIPNECH stand for and what is it?
diffuse interstitial pulmonary neuroendocrine cell hyperplasia; very small (less than 5 mm) hyperplasia; basically a precursor lesion
how do you tell apart DIPNECH and carcinoid tumors?
DIPNECH are less than 5 mm and carcinoid tumors are 5 mm or larger
what are carcinoid tumors?
5 mm or larger, they can metastasize, neuroendocrine carcinoma grade 1
what is atypical carcinoid tumors?
neuroendocrine carcinoma grade 2
how do you tell apart carcinoid tumors and atypical carcinoid tumors?
atypical carcinoid tumors have increased mitotic activity, NECROSIS, and disordered growth; increased rates of metastasis
what is carcinoid syndrome?
flushing, diarrhea, cyanosis
which neuroendocrine tumor has the greatest 5 year survival rate?
carcinoid tumors, then atypical carcinoid tumors, then small cell carcinoma
if a young man is presenting with SOB and hemoptysis and you find metastatic cancer, what two things should you be thinking about?
testicular cancer or melanoma
