title: The surgical pathology of pulmonary infarcts: diagnostic confusion with granulomatous disease, vasculitis, and neoplasia.
abstract: Twenty-three cases of surgically resected pulmonary infarcts sent in consultation were reviewed to evaluate their morphology and to assess reasons for consultation. The morphology of these infarcts demonstrated that only a minority had the classical triangular shape at low magnification (26%) whereas the majority were either spherical (17%) or had a geographic pattern of necrosis (35%). The margin of the infarcted tissue often had a pseudogranulomatous appearance due to palisaded histiocytes, foam cells, or perpendicularly oriented proliferations of fibroblasts and myofibroblasts (74%) and occasional cholesterol- and hemosiderin-laden giant cells. Basophilic granular karyorrhectic necrosis was seen focally (52%) as was vascular inflammation (56%) raising the differential diagnosis of Wegener's granulomatosis or infectious granulomas. These nonclassical features combined with a low incidence of clinical hemoptysis, chest pain and pleurisy, and a primary radiographic diagnosis of 'nodule r/o malignancy' highlight the need to consider thromboembolic pulmonary infarcts in the differential diagnosis of necrotic lung nodules with a histiocytic and fibroproliferative rim.
authors.affiliation: Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213-2582, USA. yousemsa@upmc.edu
authors.forename: Samuel A
authors.initials: SA
authors.lastname: Yousem
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D015769:Granuloma, Respiratory Tract / Q000473:pathology*; D006801:Humans; D008171:Lung Diseases / Q000473:pathology; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010340:Pathology, Surgical; D054060:Pulmonary Infarction / Q000473:pathology* / Q000601:surgery; D012307:Risk Factors; D014657:Vasculitis / Q000473:pathology*