Abstract:

Malignant mixed tumor (malignant chondroid syringoma) is an extremely rare tumor. Approximately 50 cases have been described to date. Although the majority of the tumors have developed de novo, there are some cases which appeared to arise from pre-existing benign mixed tumors. Herein we report a 41 years old African-American male with malignant mixed tumor of the scalp. He presented with an ulcerated scalp mass which existed for 6 years. He noticed the mass has been enlarging for the last year. The tumor was excised with wide local margins. Ellipse of skin measuring 10.5 x 7.5 x 7.0 cm with a centered bulging, and ulcerated mass was received. Tumor measured 5.4 x 5.8 with a central ulcer of 1.5 x 1.1 cm. Microscopic examination revealed mixed cutaneous/soft tissue neoplasm exhibiting trichilemmal, follicular, eccrine, myoepithelial, chondroid and sarcomatous differentiation. The trichofollicular component consisted of cords, ducts, and keratin-filled follicular-derived cystic structures embedded in a myxoid stroma. Occasional bone and cartilage formation was noted. The chondromatous component had a sarcomatoid appearance. The mitotic count reached up to 2 mitoses per 10 high-power-fields. Foci of necrosis representing less than 50% of the tumor volume was appreciated. Immunohistochemical studies were performed. CK5/6, AE1/AE3, CAM5.2 showed positive staining in epithelial cells, whereas S100 was positive in the areas with chondroid differentiation. Taken together with special stains this histomorphology was consistent with the malignant mixed tumor of the skin. Although rare, mixed malignant tumors of the skin exist. It is the dermatopathologists role to recognize these unusual but malignant neoplasms to guide therapy.

Financial Disclosure:
No current or relevant financial relationships exist.

Menu

Ekin Ozluk, MD