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Angiomyolipoma with epithelial cysts of the kidney in a man

Shuji Mikami1, Mototsugu Oya, Makio Mukai

  • 1Division of Diagnostic Pathology, Keio University Hospital, Tokyo, Japan. mikami-s@sc.itc.keio.ac.jp

Pathology International
|September 20, 2008
PubMed

Insights

A rare renal tumor, angiomyolipoma with epithelial cysts (AMLEC), was identified in a Japanese man. This case highlights AMLEC as a crucial consideration in adult renal neoplasm diagnosis.

Area of Science:

  • Urology
  • Pathology
  • Oncology

Background:

  • Angiomyolipoma (AML) is a benign tumor comprising vascular, smooth muscle, and adipose tissue.
  • Angiomyolipoma with epithelial cysts (AMLEC) is a recently described cystic variant of AML.

Observation:

  • A 55-year-old man presented with microhematuria, leading to the discovery of a left renal tumor.
  • Histological examination revealed a tumor with epithelial cysts, compact subepithelial stroma, and muscle-predominant AML.
  • Immunohistochemical analysis showed specific markers (HMB-45, ER, PR, CD10, SMA, desmin) in the stromal and AML components, distinct from the epithelial cysts.

Findings:

  • The renal tumor was diagnosed as AMLEC, supported by HMB-45 positivity in the subepithelial stroma and muscle-predominant AML.
  • The patient remained disease-free for 2 years post-partial nephrectomy.

Implications:

  • This case report is the first documented instance of AMLEC in Japan.
  • The findings suggest AMLEC should be included in the differential diagnosis for adult renal neoplasms.
  • This case contributes to the understanding of rare renal tumor variants.

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