Pulmonary Arterial Hypertension Abida K. Haque Pulmonary arterial hypertension (PAH) is defined as a sustained elevation of pulmonary arterial pressure greater than 25 mm Hg at rest or greater than…

Pulmonary Capillary Hemangiomatosis Abida K. Haque Pulmonary capillary hemangiomatosis lesions are seen in association with pulmonary veno-occlusive disease and pulmonary hypertension. Histologic Features

Nodules Resembling Granulomas Some lesions may grossly or microscopically mimic granulomas and enter into their differential diagnosis. These lesions include rheumatoid nodules and nodules arising in malakoplakia. Part 1 Rheumatoid…

Foreign-Body Granulomas Foreign-body granulomas may occur in the lung in the setting of intravenous drug abuse, chronic aspiration, and mineral oil aspiration, among other situations. Part 1 Intravenous Drug Abuse…

Hematologic Malignancies Primary non-Hodgkin lymphomas (NHLs) of the lung are relatively rare, comprising fewer than 1% of primary pulmonary neoplasms and fewer than 10% of extranodal lymphomas. The most common…

Nodular Amyloidosis Timothy C. Allen Mary L. Ostrowski Nodular amyloidosis is a rare lesion that generally presents incidentally in adults as a 1- to 4-cm slow-growing nodule. The nodules are…

Sarcoidosis Abida K. Haque Sarcoidosis is a systemic disease of unknown etiology, characterized by formation of noncaseating granulomas in the lung, lymph nodes, and multiple other organs. Patients are often…

Necrotizing Sarcoid Granulomatosis Alvaro C. Laga Timothy C. Allen Abida K. Haque Necrotizing sarcoid granulomatosis (NSG) is an unusual pulmonary lesion first described by Liebow and thought to represent a…

Berylliosis Abida K. Haque Beryllium is a lightweight metal used in the aerospace and electronic industries and in the manufacture of thermal couplings, atomic reactors, and fluorescent lights. Exposure to…