Abstract
Malignant granular cell tumor is a rare malignant tumor of the soft tissue. A case of primary malignant granular cell tumor of the uterine body observed in a 53 year-old woman with complaints of lumbago and lower abdominal pain was reported. The case was diagnosed as having a tumor of the uterus and underwent abdominal simple hysterectomy with bilateral adnexe. Many semispherical dark red to red-brown tumors were observed at the rear wall of the removed uterus and a section of the tumor was colored pale yellow. Histological examination revealed pleomorphic tumor tissue, abundant cytoplasm with diastase resistant PAS positive granules, swollen nuclei and nucleoli, a great amount of mitosis and multinucleated giant cells, strong infiltration and proliferation in vascular canals around the tumor, which all suggested an unfavorable prognosis. Imprinted smears revealed a somewhat dirty background due to necrosis, dispersed tumor cells, irregular polygonal cells with obscure boundary, cytoplasm with granules, nuclei of irregular size, many swollen nucleoli and outstandingly large nucleoli in the multinucleated giant cells. Differential diagnosis from clear cell carcinoma or uterine sarcoma was considered to be necessary for this tumor. Many theories have been presented as to the histogenesis of this tumor but none is considered to be determinant.
