Epithelioid Angiomyolipoma in a Patient With Li-Fraumeni Syndrome: Rare Pathologic Diagnosis

ABSTRACT Objective: Li-Fraumeni syndrome (LFS) is a rare familial cancer syndrome characterized by a high frequency of early onset tumors of various types, including adrenocortical carcinoma. Epithelioid angiomyolipoma (EAML) is an uncommon mesenchymal tumor that has malignant potential and typically found in the kidneys. To our knowledge, this is the first report of adrenal EAML in a patient with LFS. Methods: We report a 26-year-old Asian woman with breast cancer and left adrenal mass that was initially diagnosed as adrenocortical carcinoma and started on adjuvant mitotane therapy. The patient's family history was suggestive of LFS. The patient was referred to our institution for further evaluation. Results: Comprehensive TP53 gene sequencing revealed a missense mutation in exon 8 ([C.817 C>T [p.Arg273 Cys]). Pathologic review revealed large epithelioid tumor cells that stained positive for human melanoma black (HMB)-45, melan-A (A-103), and melanoma antigen recognized by T cells 1 (MART)-1 (Ab3) but stained negative for calretinin, cytokeratin, and S100. In addition, there were few smooth muscle cells with vacuolated cytoplasm. The morphologic features and immunohistochemical staining profile were consistent with EAML; thus, adjuvant mitotane therapy was withheld, and clinical observation was recommended. Conclusion: The differential diagnosis of adrenal masses in patients with LFS includes adrenocortical carcinoma, benign adrenal adenoma, and metastatic tumors. Despite the rarity of EAML in the adrenal gland, it can be added to the differential diagnosis of adrenal masses in patients with LFS. An experienced pathologic review and comprehensive immunohistochemical staining are needed to increase the diagnostic accuracy in adrenal tumors suspicious for adrenocortical carcinoma. Abbreviations: AML = angiomyolipoma EAML = epithelioid angiomyolipoma LFS = Li-Fraumeni syndrome PEComa = perivascular epithelioid cell neoplasm