Fiegen Anthony P, Tjarks B Joel, Jassim Ali D
University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota.
Department of Pathology, University of South Dakota, Sanford School of Medicine, Sioux Falls, South Dakota.
S D Med. 2018 Apr;71(4):164-166.
Primary cutaneous osteosarcoma is an exceedingly rare malignant mesenchymal neoplasm of the skin which produces bone, osteoid, or chondroid material and does not involve the underlying bone. The most common site for extraskeletal osteosarcoma is in the deep soft tissues of the thigh, upper extremities, and retroperitoneum; however, it may occur anywhere in the body. Involvement of the skin is rare and when it does occur it is more commonly due to metastatic disease rather than a primary malignancy. Only 16 cases of primary cutaneous osteosarcoma have been described in the literature. We report an uncommon case of primary cutaneous osteosarcoma. Our patient is an 84-year-old male with an unremarkable medical history who presented to the dermatology clinic complaining of a 0.5 x 0.4 cm pink flesh to translucent-appearing, shiny, papule on the right superior jawline which was not connected to the underlying bone. Clinically the differential diagnosis included basal cell carcinoma, trichoepithelioma, and other cutaneous adnexal tumors. An excisional biopsy was performed which demonstrated an unremarkable epidermis with a hypercellular reticular dermis with occasional large spindled cells with amphophilic cytoplasm. The deep dermis was involved by mature osteoid formation and infiltration of highly mitotically active, atypical epithelioid and spindled cells with abundant nuclear pleomorphism, amphophilic cytoplasm, and poorly defined cell borders. Occasional multinucleate forms were seen. Immunohistochemistry was performed which showed strong positive staining with vimentin. Without connection to the underlying bone, osteosarcoma of periosteal, parosteal, or osseous origin was excluded. Based on these histomorphologic findings, a diagnosis of primary cutaneous osteosarcoma was made. Our case adds to the dearth of literature regarding primary cutaneous osteosarcoma and provides primary care physicians, dermatologists, and pathologists much needed insight into this rare condition.
原发性皮肤骨肉瘤是一种极其罕见的皮肤恶性间叶性肿瘤，可产生骨、类骨质或软骨样物质，且不累及深部骨骼。骨外骨肉瘤最常见的部位是大腿、上肢和腹膜后的深部软组织；然而，它可发生于身体的任何部位。皮肤受累罕见，一旦发生，更常见的是转移性疾病而非原发性恶性肿瘤。文献中仅描述了16例原发性皮肤骨肉瘤病例。我们报告一例不常见的原发性皮肤骨肉瘤病例。我们的患者是一名84岁男性，既往病史无特殊，因右侧上颌骨缘出现一个0.5×0.4 cm大小的粉红色至半透明、有光泽的丘疹就诊于皮肤科诊所，该丘疹与深部骨骼无连接。临床上鉴别诊断包括基底细胞癌、毛发上皮瘤和其他皮肤附属器肿瘤。进行了切除活检，结果显示表皮无异常，网状真皮细胞增多，偶见大的梭形细胞，胞质嗜双色。深部真皮有成熟类骨质形成，并见有高度有丝分裂活性、非典型上皮样和梭形细胞浸润，核多形性丰富，胞质嗜双色，细胞边界不清。偶见多核细胞形态。进行了免疫组化检查，结果显示波形蛋白呈强阳性染色。由于与深部骨骼无连接，排除了骨膜、骨旁或骨源性骨肉瘤。基于这些组织形态学表现，诊断为原发性皮肤骨肉瘤。我们的病例增加了关于原发性皮肤骨肉瘤的文献稀缺性，并为初级保健医生、皮肤科医生和病理学家提供了对这种罕见疾病急需的见解。
