Pathology of Lung Tumors

1. Pathology of Lung Tumors Margaret M. Grimes, M.D. Dept. of Pathology

2. Tumors of Lung and Pleura Carcinoma Carcinoid tumor Metastatic tumor Hamartoma Mesothelioma

3. Carcinoma of Lung(Bronchogenic Carcinoma) Most common visceral malignancy worldwide Second most common visceral ca in U.S. men and women Leading cause of cancer deaths in U.S.

7. Tobacco Use and Cancer Risk Majority of pts. are smokers Smokers at greater risk than non-smokers Prevalence parallels cigarette use Correlation between cancer rates and smoking habit Risk drops with cessation of smoking Tobacco smoke contains carcinogens Atypical cytologic changes are more frequent in smokers

9. Other Risk Factors in Lung Cancer Genetic factors Occupational dust exposure nickel, chromates, arsenic, beryllium, asbestos Radiation accidental, occupational, environmental (radon) Scarring

10. Histologic Types of Lung Carcinoma Squamous cell carcinoma Adenocarcinoma Bronchioloalveolar carcinoma Large cell undifferentiated carcinoma Small cell carcinoma

11. Squamous Cell Carcinoma Strong association with smoking Keratinization and/or intercellular bridging Mostly central May be large, cavitate May be associated with hypercalcemia

14. Adenocarcinoma Most common type in women and non-smokers Gland formation and/or mucin production Mostly in peripheral lung; may be scar-associated Distinguish from metastatic carcinoma

16. Bronchioloalveolar Carcinoma(subtype of adenocarcinoma) Tumor cells grow �in situ� along pre-existing alveolar septa Solitary mass, multiple nodules or diffuse process May be associated with abundant mucus production

20. Small Cell Carcinoma Strong association with smoking High nuclear/cytoplasmic ratio; �oat cell� Mostly central Has usually already metastasized at dx Neuroendocrine tumor;ectopic hormone production

22. Large Cell Undifferentiated Carcinoma No obvious histologic differentiation Not small cell May be central or peripheral

28. Superior Vena Cava Syndrome Compression of s.v.c. by tumor, less often by benign pathology Venous congestion, dusky cyanosis of head/neck/upper extremities

31. Pancoast�s tumor Carcinoma in lung apex with invasion of apical chest wall Invasion of sympathetic ganglia, brachial plexus Horner�s syndrome, arm pain

34. Paraneoplastic syndromes Peripheral neuropathy, Lambert-Eaton syndrome Hypertrophic osteoarthropathy Myopathy; skin lesions

35. Ectopic hormone production ACTH ADH Calcitonin Gonadotropins PTH Small cell carcinomas most frequently associated (hypercalcemia most often associated with squamous cell carcinoma)

36. Pathogenesis: As in other carcinomas, activation of oncogenes and/or loss of tumor suppressor genes K-Ras p53 Rb

37. Prognosis depends on clinical stage, histology Overall 5-year survival = 10-15% 65% present as Stage III Stage I tumors: 50% 5-year survival Small cell carcinoma has worst prognosis

39. Carcinoid Tumor Neuroendocrine tumor 1-5% of all lung tumors M=F No known risk factors

40. Carcinoid Tumor Usually presents as a nodule on chest x-ray, either central or peripheral

44. Bronchial Carcinoid Tumor Low grade malignant neoplasm 90-95% 5-year survival 5-10% metastasize to regional lymph nodes

45. Metastatic Tumors Variety of primary sites Patterns of metastasis: Multiple nodules Solitary nodule (e.g. kidney, colon, thyroid) Diffuse infiltrate (lymphangitic ca)

48. Metastatic Carcinoma Histology usually resembles that of primary tumor Most are adenocarcinomas (must differentiate from primary lung adenocarcinoma)

49. Hamartoma Benign neoplasm Usually found incidentally as a nodule on chest x-ray Occasionally causes bronchial obstruction Excision is curative Histology: mixture of cartilage, adipose and fibrous tissue