Overview Non-Hodgkin lymphoma (NHL) is a heterogeneous group of diseases that accounts for 90% of lymphoma diagnoses, with the other 10% being Hodgkin lymphoma (HL). NHL arises during lymphocyte differentiation in either the humoral or cell-mediated immunity lineages of the…
Pulmonary Lymphoid Hyperplasia (Follicular Bronchiolitis) Etiology, Prevalence, and Epidemiology Pulmonary lymphoid hyperplasia, also known as follicular bronchiolitis or hyperplasia of bronchus-associated lymphoid tissue, is a benign condition characterized histologically by the presence of polyclonal lymphoid aggregates along the bifurcation of…
Etiology, Prevalence, and Epidemiology Pulmonary metastases are common—present at autopsy in 20% to 54% of patients with extrapulmonary malignancy. The most common primary sites associated with pulmonary metastases in biopsy series are the breast, colon, kidney, uterus, bladder, melanoma, and…
Etiology, Prevalence, and Epidemiology Inflammatory pseudotumor, also known as inflammatory myofibroblastic tumor, is a quasineoplastic lesion that clinically and radiologically tends to mimic a malignant neoplasm and that histologically consists of a mixture of inflammatory cells, myofibroblastic spindle cells, and…
Etiology, Prevalence, and Epidemiology Pulmonary hamartomas are benign neoplasms, probably derived from bronchial wall mesenchymal cells. Hamartomas are the most common benign pulmonary neoplasm and account for about 8% of primary lung tumors. Although they may be seen in adolescents…
Neuroendocrine Hyperplasia and Pulmonary Tumorlets Etiology, Prevalence, and Epidemiology Normal lung tissue contains scattered neuroendocrine (Kulchitsky) cells within the bronchial and bronchiolar epithelium. These cells play a role in the detection of hypoxia as well as fetal lung development and…
Schemes for Staging The most widely used scheme for staging non–small cell lung cancer (NSCLC) is the TNM classification. A variety of alterations in this scheme have been made to better group patients with similar prognosis and treatment options. The…
Etiology Lung cancer arises when cells lining the bronchi or peripheral airways undergo neoplastic change in response to an inciting agent or agents. The most common and well-recognized cause of lung cancer is cigarette smoking, which has been unequivocally linked…
Background Lung cancer is the third most common cancer and the leading cause of cancer-related death in the United States. The most important risk factor for lung cancer is smoking, which results in approximately 85% of all US lung cancer…
Etiology Since the recognition of human immunodeficiency virus (HIV) infection as the cause of acquired immune deficiency syndrome (AIDS) in the 1980s, many changes have occurred in the demographics, complications, and treatment of this disease. AIDS is the most advanced…