78 Primary Adrenal Gland Epithelioid Sarcoma. (11th January 2018) - Huang, Xiao
Abstract: Epithelioid sarcoma is a malignant mesenchymal neoplasm with morphologic and immunophenotypic epithelioid differentiation, which rarely arises in solid organs. We report one case of primary epithelioid sarcoma in the adrenal gland of a 31-year-old woman. The patient initially presented with nausea and rectal bleeding, and a subsequent imaging study revealed a 4.2cm left adrenal gland mass and left retroperitoneal lymphadenopathy. Clinical and radiological studies did not reveal tumor elsewhere in the patient. Histologic features were those of epithelioid sarcoma, proximal type, with epithelioid cohesive clusters tumor cells harboring frequent mitoses and areas of necrosis. Immunohistochemical study showed strong, diffuse expression of epithelial markers (pancytokeratin), CD34, and Fli-1. Partial and focal positivity with CK7 and CD31 was noted. Nuclear expression of SMARCB1 (INI-1) protein was lost. ERG is negative in this case. Due to this unusual location, adrenal cortical carcinoma was initially considered at the time of immediate assessment. However the cytomorphology and negative stains with inhibin, calretinin and Melan A ruled it out. We believe that this is the second case report of primary adrenal gland epithelioid sarcoma. Fli-1 positivity is seen in our case, and ERG is not positive as shown in recent publication for some epithelioid sarcomas. Negativity of INI-1 stain is key for the correct diagnosis.