Imprint cytology of epithelioid angiomyolipoma in a patient with tuberous sclerosis. A case report.
BACKGROUND
Angiomyolipoma composed predominantly of epithelioid cells has been referred to as epithelioid angiomyolipoma. As this subtype shows considerable cellular atypia, it may be erroneously diagnosed as malignant epithelioid tumor, such as renal cell carcinoma and hepatocellular carcinoma. So far, only one report describing the cytologic findings of epithelioid angiomyolipoma has been documented, and epithelioid angiomyolipoma occurring in the peritoneal cavity has not been reported.


METHODS
Eleven years after resection of a renal epithelioid angiomyolipoma in a 34-year-old male with tuberous sclerosis, a tumor appeared in the peritoneal cavity and three masses in the liver. The intraoperative smears imprinted from part of the peritoneal mass revealed many large, atypical cells. The well-preserved atypical cells showed abundant, round to polyhedral, granular cytoplasm. Bizarre, giant nuclei with hyperchromasia and huge nucleoli were occasionally seen. Intranuclear cytoplasmic inclusions and mitotic figures were occasionally observed. As the epithelioid cells were markedly pleomorphic, we could not rule out hepatocellular carcinoma, cytologically and histologically, in the intraoperative consultation. In permanent sections the tumor was composed predominantly of epithelioid cells showing an alveolar pattern or sheetlike arrangement. Mitotic counts were zero to one per 10 high-power fields. Immunohistochemically, the epithelioid tumor cells were positive for vimentin, alpha-smooth muscle actin and HMB-45, consistent with epithelioid angiomyolipoma. MIB-1-labeling index was 1.6%.


CONCLUSIONS
When one sees atypical epithelioid tumor cells in a tuberous sclerosis patient during an intraoperative consultation, one must consider epithelioid angiomyolipoma.
Hino
Akiko
A
Department of Pathology, University of Tokushima School of Medicine, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan.
Hirokawa
Mitsuyoshi
M
Takamura
Kazuhito
K
Sano
Toshiaki
T
D000199:Actins / Q000032:analysis / Q000276:immunology; D000328:Adult; D018207:Angiomyolipoma / Q000737:chemistry / Q000150:complications / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000032:analysis; D006528:Carcinoma, Hepatocellular / Q000473:pathology; D002292:Carcinoma, Renal Cell / Q000473:pathology; D002466:Cell Nucleolus / Q000473:pathology; D002467:Cell Nucleus / Q000473:pathology; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000737:chemistry / Q000150:complications / Q000473:pathology*; D008297:Male; D009130:Muscle, Smooth / Q000737:chemistry; D010529:Peritoneal Cavity / Q000473:pathology; D013997:Time Factors; D014402:Tuberous Sclerosis / Q000150:complications*; D014746:Vimentin / Q000032:analysis / Q000276:immunology
D000199:Actins; D014408:Biomarkers, Tumor; D014746:Vimentin