Iatrogenic implantation of malignant meningioma to the abdominal wall

We report a case of malignant meningioma that occurred in the abdominal operation scar of a 71-year-old woman. This tumor was a 13 x 8 cm gray-tan soft tumor, consisting of multiple nodules. Histologically, tumor cells proliferated in the subcutaneous tissue, displaying mostly a storiform pattern and a focal whorl formation with high mitotic figures. The immunohistochemical positivity for epithelial membrane antigen and negativity for CD34 enabled us to differentiate this tumor from a dermatofibroma protuberance or hemangiopericytoma. The patient had a history of operation for a recurrent orbital lesion of a malignant meningioma that initially developed in the frontal skull base. The present case probably resulted from iatrogenic transplantation of the orbital malignant meningioma to the lower abdominal wall, which had served as a donor site for adipose tissue used to pack the orbital defect.