Pathology Flashcards
What is the etiology of lung cancers occurring in non smokers?
More common in women
Most adenocarcinomas
Tend of have EGFR and not KRAS mutations
What is the relationship between smoking and lung cancers?
11% of heavy smokers will develop lung cancer
Squamous and small cell carcinomas show strongest association with tobacco
Moderate association with adenocarcinoma and large cell carcinoma
What are central vs. peripheral tumors?
Central - squamous cell, small cell carcinomas
Peripheral - adenocarcinoma, large cell carcinoma
How are lung cancers divided based on histology?
Non small lung cell - 75-80% - metastases at diagnosis common - treated surgically if resectable
Small cell - almost always metastases at diagnosis, responsive to chemotherapy, RB mutations common
What gene mutations are seen in adenocarcinomas?
KRAS mutations
EGFR mutations - Asians, women, non smokers
ALK rearrangements - non smokers, signet ring morphology
Which lung neoplasms have no association with smoking?
Bronchial carcinoids
Mesotheliomas
What are the basics of squamous cell carcinoma?
Men more than women, smokers
Large lesions with central necrosis
Slower to form distant metastases than other types but can spread to hilar lymph nodes
Central tumors - close to trachea or bronchi
What is the pathology of squamous cell carcinoma?
Keratinization (squamous pearls)
Intercellular bridges
Tadpole cells with red cytoplasm
What is the pathogenesis of squamous cell carcinoma?
Preceded by metaplasia and dysplasia then carcinoma in situ
Higher frequency of p53 mutations
Precursor lesions = goblet cell hyperplasia, basal cell hyperplasia, squamous metaplasia
What is an adenocarcinoma?
Malignant epithelial tumor with glandular differentiation and/or mucin production
Distant metastasis early in course but slow growth
Acinar, papillary, or solid pattern
What is the pathogenesis of adenocarcinoma?
Atypical adenomatous hyperplasia - bronchioloalveolar carcinoma - invasive adenocarcinoma sequence
Mutations and amplifications of EGFR (mostly in women, non smokers, Chinese) - can be treated with tyrosine kinase inhibitors
KRAS mutations has resistance to TK inhibitors and worse prognosis
What is adenocarcinoma in situ (bronchioloalveolar carcinoma)?
Grows in monolayer in lepidic pattern along alveolar septa without invasion or destruction of architecture
3 cm or less in size
Nonmucinous - single nodule, amenable to surgery, excellent prognosis
Mucinous - satellite nodules, less cured by surgery
What is atypical adenomatous hyperplasia?
Pre neoplastic lesion of small (<.5 cm) focus of type 2 pneumocystis proliferation with mild cytologic atypia
What are the basic features of large cell carcinoma?
Undifferentiated malignant epithelial tumor
Large cells with vesicular nuclei, prominent nucleoli, no obvious glandular or squamous differentiation
Mostly diagnosis of exclusion - malignant and poor prognosis
What is the pathogenesis of small cell carcinoma?
P53 and RB mutations
Arises from neuroendocrine cells
No Pre invasive or carcinoma in situ phase
What is the pathology of small cell carcinoma?
Main stem bronchi with early involvement of hilar and mediastinal nodes
Small cells with scant cytoplasm, finely granular chromatin, inconspicuous nucleoli
Prominent nuclear molding and crush artifact
Azzopardi effect - Nuclear material from crushed cells cling to blood vessels and cause them to stain blue on H&E
What are bronchial carcinoids?
Rare well differentiated neuroendocrine tumors
Young and non smokes
Resectable and curable
Carcinoid syndrome - diarrhea, flushing, cyanosis - may be present
Rosette formation - uniform cells with regular nucleus, salt and pepper chromatin, are mitosis and no necrosis
Typical carcinoid - atypical carcinoid - small cell continuum
What are paraneoplastic syndromes associated with lung cancers?
Small cell carcinoma - ACTH and ADH production - Cushing’s and SIADH
Squamous cell carcinoma - PTH like hormone - hypercalcemia
Gonadotropins - gynecomastia
Serotonin and bradykinin - carcinoid syndrome
What are associated presentations of lung cancers?
Vena caval syndrome (upper lobe lesions)
Horner syndrome - ptosis, pupil constriction, anhydrosis
Pancoast syndrome - pain in distribution of ulnar nerve due to brachial or cervical sympathetic plexus invasion
What are the most frequent metastases to the lung?
Breast
Colon
Kidney
What is the most common cause for pleural effusion?
CHF - Transudative effusion
What are the most common cause of exudative effusions?
Microbial infections
Cancer
Pulm infarction
Viral pleuritis
How do pleural effusions resolve?
Transudative tend to resorb once cause alleviated
Exudative can lead to fibrinous organization and eventual scarring of pleural surfaces, sometimes calcification
What is mesothelioma?
Rare cancer of mesothelial cells arising in parietal or visceral pleura
Common association with asbestos exposure - incubation can be 25 yrs or more
Some association with SV40 DNA virus - t antigen can bind and inactivate p53 and RB
What are the different types of asbestos fibers?
Serpentine - chrysotile - flexible, more common, low oncogenicity
Amphibole - crocidolite - brittle, less prevalent, more oncogenic
Asbestos bodies = asbestos fibers coated with iron rich material found in lungs
What is the immunohistochemistry of mesothelioma?
Stain with calretinin and CK 5/6
Adenocarcinomas stain with MOC31 and CEA
What is the pathology of mesothelioma?
Lung becomes ensheathed by thick fleshy tumor
Can have pleural effusions
Epithelioid and spindle (sarcomatoid) cell types
Can form papillary, tubular, or glandular structures resembling adenocarcinoma - differentiate with immunohistochemistry
What is Samter’s triad?
Asthma
Nasal polyps
Aspirin sensitivity
All cause excess leukotrienes
What are nasal polyps?
Benign Outgrowth of nasal mucosa
Associated with chronic rhino sinusitis, asthma, allergies, CF
Intact mucosa overlying edematous and inflamed lamina propria
What is sinonasal papilloma?
Benign tumor of sinonasal mucosa - arises in squamous or columnar epithelium of sinonasal tract
3 types - exophytic/septal, endophytic/inverted (can be locally aggressive and recur, grows inward from surface, lateral walls), cylindrical
Low risk HPV types (6, 11) associated
Treatment is surgical excision
What is nasopharyngeal angiofibroma?
Benign mesenchymal, highly vascular tumor - bleeds excessively
Seen in adolescent boys - testosterone driven
Locally aggressive - may invade bone and recur
Numerous thin walled blood vessels in cellular fibrous stroma
Treatment is surgical excision
What is nasopharyngeal carcinoma?
Common in adult Chinese and pediatric African population
Strong association with EBV
3 histologic patterns - keratinizing squamous cell, non keratinizing squamous cells, undifferentiated (large epithelial cells in syncytium pattern with heavy lymphocytic infiltrate = lymphoepithelioma)
Treatment is radiotherapy with/without chemo
What are necrotizing lesions of nose and UR tract?
Acute infections - fungus esp in diabetics, tb, immunocompromised
Vasculitis - wegener
Cocaine abuse
Neoplastic
What are vocal cord nodules/polyps?
Smoking or voice abuse
Small protrusions in vocal cord
Benign squamous epithelium overlying edematous myxoid stroma
May spontaneously regress, can be surgically excised
What is laryngeal papilloma?
Benign neoplasm
Multiple and bilateral in children, adults can have single lesion
Often recur
Small raspberry like masses on true vocal cord
Squamous epithelium lined finger like projections with central fibromuscular cores
Associated with HPV 6, 11
What is carcinoma of the larynx?
More common in men over 40
Associated with smoking, alcohol, asbestos, irradiation, HPV
Most are squamous cell
Clinically presents as hoarseness
Begin as pearly plaques of SCC in situ - ultimately infiltrates, ulcerates, and fungates
Treatment is surgery, radiation or combo - prognosis better in organ confined disease, 1/3 die
What is the field effect?
Cigarette smoking exposes multiple areas to carcinogens and these patients often develop multiple SCCs in upper and lower respiratory tracts
What is the relationship between HPV and head and neck squamous carcinomas?
Over half infected with high risk HPV, esp 16
HPV tumors less likely to have p53 mutations
HPV positive patients better overall and disease specific survival
More common in sinonasal papillomas, laryngeal papillomas, squamous carcinomas
What is atelectasis and what are the three types?
Collapse of previously inflated lung
3 types - resorptive/obstructive (complete obstruction with absorption of air in distal airway, mediastinum shifts toward source, reversible), compressive (external force compresses lung, mediastinum shifts away, reversible), contraction (fibrosis prevents expansion, mediastinum shifts toward source, irreversible)
What is the hallmark of obstructive lung disease?
FEV1/FVC ratio <80%