The surgical pathology of pulmonary infarcts: diagnostic confusion with granulomatous disease, vasculitis, and neoplasia

Mod Pathol. 2009 May;22(5):679-85. doi: 10.1038/modpathol.2009.20. Epub 2009 Mar 13.

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.

MeSH terms

  • Adult
  • Aged
  • Diagnosis, Differential
  • Female
  • Granuloma, Respiratory Tract / pathology*
  • Humans
  • Lung Diseases / pathology
  • Lung Neoplasms / pathology*
  • Male
  • Middle Aged
  • Pathology, Surgical
  • Pulmonary Infarction / pathology*
  • Pulmonary Infarction / surgery
  • Risk Factors
  • Vasculitis / pathology*