Neoplastic lung disease

Cancer that has metastasized to the lungs is more common than primary lung cancer. That said, most primary lung cancer is has metastasized (Stage 4) by time of diagnosis.

Most primary lung cancer (~95 percent) is bronchogenic carcinoma; 5 percent is bronchial carcinoid and miscellaneous tumors.

Bronchogenic carcinoma is most frequently diagnosed cancer, and the most frequent cause of death from cancer.

Smoking is the main risk factor for small cell and squamous cell lung cancer. Polycyclic aromatic hydrocarbons cause DNA damage are are "initators" of cancer.

Mediastinal symptoms: hoarseness (recurrent laryngeal nerve injury), dysphagia (compression on esophagus), Horner's syndrome (usually squamous cell tumor at extreme apex of lung destroying the superior cervical sympathetic ganglion: ptosis, miosis, anhydrosis), SVC syndrome, hemorrhagic pericarditis.

Paraneoplastic syndromes: Small cell secrete ADH, ACTH, also associated with Eaton-Lambert syndrome; squamous secretes PTH and cause hypercalcemia; adenocarcinomas associated with hypertrophic pulmonary osteoarthropathy (associated with clubbing) and migratory thrombophlebitis (also seen in pancreatic adenocarcinoma); carcinoid tumor associated with carcinoid syndrome (excess serotonin gives flushing, diarrhea, salivation, wheezing).

Mesothelioma has Psammoma bodies and results in hemorrhagic pleural effusions and pleural thickening.

Common areas of metastasis: Sometimes Cancer Penetrates Benign Liver, Lots of Bad Stuff Kill Glia, PT Barnum Likes (lytic) Kids. Also adrenals and contralateral lung.

Small cell versus non-small cell. Small cell usually metastatic at presentation; surgery contraindicated.

SQUAMOUS CELL CARCINOMA

Preceded by squamous metaplasia, dysplasia, carcinoma in situ, finally breaks through basement membrane. Squamous, Sentral, Smoking; associated with cavitation; hilar mass arising from bronchus, keratin pearls, intracellular bridges.

ADENOCARCINOMA

Associated with women, nonsmokers. Peripheral, associated with scarring or site of previous injury or inflammation. Glandular histology (Clara cell derived, produces mucin -- blue and foamy) and papillary growth pattern.

Bronchioloalveolar carcinoma subtype: in situ growth pattern, no evidence of stromal, vascular, or pleural invasiveness. Much better prognosis.

LARGE CELL TUMOR

Peripheral. Highly anaplastic, pleomorphic tumor. Poor prognosis. Removed surgically.

CARCINOID TUMOR

Carcinoid syndrome.