title: Angiomyolipoma with epithelial cysts of the kidney in a man.
abstract: Angiomyolipoma (AML) is a well-characterized tumor composed of vascular, smooth muscle and adipose elements. Recently, AML with epithelial cysts (AMLEC) has been described as a cystic variant of AML. Herein is reported an AMLEC in a 55-year-old man, and to the authors' knowledge this is the first case report of AMLEC in Japan. He was referred to hospital because of microhematuria. A left renal tumor was noted and partial nephrectomy was performed. Histology indicated that the tumor was composed of epithelial cysts, compact subepithelial stroma and muscle-predominant AML. Immunohistochemically, the subepithelial compact stroma and muscle-predominant AML were positive for HMB-45, estrogen receptor (ER), progesterone receptor (PR), CD10, smooth-muscle actin and desmin. Epithelial cysts were positive for pancytokeratin but negative for HMB-45, ER and PR. This tumor was diagnosed as AMLEC, mainly based on the immunohistochemical result that subepithelial compact stroma and muscle-predominant AML were positive for HMB-45. The patient was alive with no evidence of recurrence at 2 years postoperatively. This case was very interesting because it suggests that AMLEC should enter into the differential diagnosis of adult renal neoplasms.
authors.affiliation: Division of Diagnostic Pathology, Keio University Hospital, Tokyo, Japan. mikami-s@sc.itc.keio.ac.jp
authors.forename: Shuji
authors.initials: S
authors.lastname: Mikami
authors.forename: Mototsugu
authors.initials: M
authors.lastname: Oya
authors.forename: Makio
authors.initials: M
authors.lastname: Mukai
mesh_terms: D000199:Actins / Q000378:metabolism; D018207:Angiomyolipoma / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D000951:Antigens, Neoplasm / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D003893:Desmin / Q000378:metabolism; D018572:Disease-Free Survival; D006417:Hematuria; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D007680:Kidney Neoplasms / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D008297:Male; D058950:Melanoma-Specific Antigens; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism; D015260:Neprilysin / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism
chemical_list: D000199:Actins; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D003893:Desmin; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D015260:Neprilysin