*Foot and Ankle Specialists of the Mid-Atlantic LLC, Rockville, MD.
J Am Podiatr Med Assoc. 2023 Jan-Feb;113(1). doi: 10.7547/21-064.
Malignant melanoma with osteocartilaginous differentiation is extremely rare. We report a case of periungual osteocartilaginous melanoma (OCM) on the right hallux. A 59-year-old man presented with a rapidly growing mass with drainage on his right great toe after treatment of ingrown toenail and infection 3 months earlier. Physical examination showed a 2.0×1.5×1.0-cm, malodorous, erythematous, dusky, granuloma-like mass along the fibular border of the right hallux. Pathologic evaluation of the excisional biopsy revealed diffuse epithelioid and chondroblastoma-like melanocytes with atypia and pleomorphism in the dermis with strong SOX10 immunostaining. The lesion was diagnosed as osteocartilaginous melanoma. The patient was referred to a surgical oncologist for further treatment. Osteocartilaginous melanoma is a rare variant of malignant melanoma that needs to be differentiated from chondroblastoma and other lesions. Immunostains for SOX10, H3K36M, and SATB2 are helpful for the differential diagnosis.
具有骨软骨分化的恶性黑色素瘤极为罕见。我们报告一例发生于右踇趾甲旁的骨软骨性黑色素瘤（OCM）。一位 59 岁男性，3 个月前因嵌甲和感染行治疗后，右大脚趾出现快速生长的肿块，伴分泌物。体格检查显示右踇趾腓侧缘有一个 2.0×1.5×1.0cm 的、有臭味的、红斑的、暗褐色的、类肉芽肿样肿块。切除活检的病理评估显示真皮内弥漫性上皮样和软骨母细胞瘤样黑色素细胞具有异型性和多形性，且 SOX10 免疫染色强阳性。该病变被诊断为骨软骨性黑色素瘤。患者转至外科肿瘤医生处进一步治疗。骨软骨性黑色素瘤是恶性黑色素瘤的罕见变异型，需要与软骨母细胞瘤和其他病变相鉴别。SOX10、H3K36M 和 SATB2 的免疫染色有助于鉴别诊断。
