Malignant peripheral nerve sheath tumor with glandular differentiation. Report of a case with emphasis to the usefulness of immunohistochemistry in the differential diagnosis.

A case of malignant nerve sheath tumor with glandular differentiation in a patient with neurofibromatosis is presented. In the spindle celled areas the tumor cells reacted strongly with vimentin and S-100 protein, while the glandular epithelia reacted with EMA, cytokeratins (peptides 8, 19, and 20) and CEA, as well as a few of them also with chromogranin. Based on the results of immunohistochemical profile of the tumor cells, the differential diagnosis of this rare soft tissue tumor from biphasic synovial sarcoma with glands, as well as its distinction from any other spindle cell sarcoma with entrapped skin appendages could be greatly facilitated.