Retroperitoneal Malakoplakia Mimicking Metastatic Disease

Clin Nucl Med. 2025 Jan 1;50(1):75-76. doi: 10.1097/RLU.0000000000005536. Epub 2024 Oct 30.

Abstract

Malakoplakia is a rare inflammatory granulomatous disease that can produce a tumor-like appearance in nearly any organ system. Imaging findings of malakoplakia overlap with malignancy and tissue sampling are typically required for definitive diagnosis. We present a case of a 66-year-old woman with a previous history of liver adenocarcinoma status post resection that subsequently developed an intensely FDG-avid retroperitoneal mass on surveillance imaging. CT-guided biopsy of the mass demonstrated Michaelis-Gutmann bodies, supporting the diagnosis of malakoplakia. The patient underwent antibiotic treatment with complete resolution of the mass.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Diagnosis, Differential
  • Female
  • Fluorodeoxyglucose F18
  • Humans
  • Malacoplakia* / diagnostic imaging
  • Malacoplakia* / pathology
  • Neoplasm Metastasis
  • Positron Emission Tomography Computed Tomography
  • Retroperitoneal Neoplasms / diagnostic imaging
  • Retroperitoneal Neoplasms / pathology
  • Retroperitoneal Space / diagnostic imaging
  • Retroperitoneal Space / pathology
  • Tomography, X-Ray Computed

Substances

  • Fluorodeoxyglucose F18