Path 5 (lung Neoplasms ) Flashcards
Pathogenesis of lung cancer
-smoking
-industrial exposure and air pollution
-asbestos exposure (uranium exposure as well )
Small cell carcinogen Pathogenesis
• Rb mutations
• P53 mutations
• 3p deletions (~90%)
• Myc amplifications
Adenocarcinoma Pathogenesis
• EGFR mutations
• KRAS mutations
• ALK rearrangements
• ROS1 mutations
-Non smokers
Squamous cell carcinoma Pathogenesis
-P53 mutations
-3p deletions
-CDKN2a/p16 mutations
-FGFR1 amplifications
Pancoast tumour
• Wasting of hand muscles, pain in arms (ulnar nerve)
• Horner syndrome
• Compression of blood vessels à Edema
• Recurrent laryngeal nerve paralysis
• Esophagus involvement -dysphagia
• Thoracic duct obstruction - chylothorax
-apical neoplasm - invasion of brachial or cervical sympathetic plexus
SVC syndrome
Venous congestion and edema of the head and arm
Horner syndrome
-cervical sympathetic plexus damaged
-ipsilateral enophtalmos , ptosis , miosis , anhidrosis
Paraneoplastic syndromes
• Earliest manifestation of occult (hidden) neoplasm
Squamous cell carcinoma - paraneoplastic syndromes
-hypercalcemia (parathyroid hormone related peptide )
Small cell carcinoma - paraneoplastic syndromes
-Cushings syndrome
-syndrome of inappropriate ADH secretion
-Myasthenic like syndrome ( lambert Eaton syndrome )
Adenocarcinoma clinical features
-women and non smokers
- over 45 years of age
-more peripheral
-grow slowly
Adenocarcinoma- pre invasive lesions
-Adenocarcinoma in situ
-atypical adenomatous hyperplasia with cuboidal epithelium and mild interstitial fibrosis
-lipidic pattern
-ground glass appearance
Minimally invasive Adenocarcinoma
-Size < 3 cm
-stromal invasion < 5mm
-no pleural or lymph vascular invasion
Invasive carcinoma
-Stromal invasion
-pleural/lymphovascular invasion
-different histological types
-majority express TTF1
Squamous cell carcinoma clinical features
-central
- more in men
-smoking history
-Spreads to hilar lymph nodes
• Extra-thoracic spread is later than other histologic types
• Obstruction, atelectasis, infection
• Central necrosis - CAVITATION
• Progression: Squamous metaplasia -Squamous dysplasia -Squamous cell carcinoma in-situ-Invasive squamous cell carcinoma
Squamous cell carcinoma histo
Keratin pearls
Squamous cell differentiation
Small cell carcinoma
-central > peripheral
-smoking
Paraneoplastic syndrome
-frequent vascular invasion
-early metastasis
Small cell carcinoma histo
-round ,scant cytoplasm , finely granular chromatin ,fragile ,crush artifacts ,nuclear molding ,extensive necrosis
-azzopardj effect
-frequent mitosis
-chromagranin A dye
Large cell carcinoma
• Undifferentiated epithelial malignancy
• Lacks features of small cell
• No glandular differentiation
• No squamous differentiation
• Pleomorphic and “bizarre” cells
-poor prognosis
Carcinoid tumors
-neuroendocrine tumor of the lung
-arises from kulchitsky
Carcinoid tumor , typical variant
-centrally located
-polyploid growth
-40 y/o age range
-obstruction,cough ,hemoptysis ,infection
-localized ,but can metastize to lymph nodes
-resectable and good prognosis
Typical carcinoid histo
-regular round nuclei
-salt and pepper chromatin
-absent or rare mitosis and little pleomorphism
Atypical carcinoid
-Higher militia rate and small Foci of necrosis
-higher incidence of lymph node and distant metastasis and typical carcinodes
Carcinoid syndrome
-neuropeptides secreted into systemic circulation leading to symptoms
-serotonin , histamine ,bradykinin ,PGs
-episodic attacks :
-vasomotor disturbances (flushes and cyanosis )
-GI hypermotility
-asthma attacks
Malignant mesothelioma
-malignancy of the pleura , peritonitis or pericardium
-asbestosis risk factor
-
Malignant mesothelioma clinical features
-chest pain
-dyspnea
-cough/ fatigue
Diagnosis of malignant mesothelioma
-moderate to large unilateral pleural effusion
-nodular pleural thickening
-enhancement with PET scan
Mesothelioma histo
-biphasic
-sarcomatoid
-epitheliod
Pulmonary Hamartoma
- appears as rounded radio-opacity (coin lesion ) on chest x ray
Histo : Nodules of connective tissue (cartilage/ fibrous tissue/ fat) along with epithelial clefts.
