Etiology Langerhans cell histiocytosis (LCH) is an uncommon disease. Several synonyms, including histiocytosis X, eosinophilic granuloma, and Langerhans cell granulomatosis, have been used in the past, but the term Langerhans…
Organizing pneumonia (OP) is a histologic pattern characterized by the presence of intraluminal granulation tissue polyps within alveolar ducts and surrounding alveoli associated with chronic inflammation of the surrounding lung…
Etiology, Prevalence, and Epidemiology Idiopathic pulmonary fibrosis (IPF) has been defined as “a specific form of chronic fibrosing interstitial pneumonia limited to the lung and associated with the histologic and/or…
Etiology Systemic sclerosis (scleroderma) has three cardinal features: excessive collagen production, vascular damage, and inflammation/autoimmunity. The pathogenesis of systemic sclerosis is obscure, but there are several contributing factors, including genetic,…
Amitani and colleagues first described a unique pattern of upper lobe–predominant, idiopathic pulmonary fibrosis (IPF) in 13 patients in the Japanese literature in 1992. The currently preferred term in the…
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…
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…
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…
Etiology, Prevalence, and Epidemiology Hodgkin lymphoma (HL) is a neoplasm of B lymphocytes characterized by the presence of Reed-Sternberg cells. HL accounts for 10% of all cases of lymphoma and…
Acute interstitial pneumonia (AIP) is a severe acute disease of unknown etiology that usually occurs in a previously healthy individual and produces histologic findings of diffuse alveolar damage. The clinical,…
