Malignant Chondroid Syringoma with Bone Invasion: A Case Report and Review of the LiteratureTakahashi, Hayato MD*; Ishiko, Akira MD*; Kobayashi, Masakazu MD*; Tanikawa, Akiko MD*; Takasu, Hiroshi MD†; MD, Masuru Tanaka*American Journal of Dermatopathology: October 2004 - Volume 26 - Issue 5 - pp 403-406 Extraordinary Case Report Abstract Author Information We describe a 27-year-old Japanese female with a recurrent nodule on the left big toe and local bone invasion. Histopathologically, the tumor consisted of nests of atypical cells with few mitotic cells, which partly formed gland-like structures. Areas of myxoid degeneration, positive for Alcian blue staining and that did not stain after they were digested with hyaluronidase, were prominent in the matrix among tumor cells. Positive staining was noted in tumor cells for cytokeratin (AE1+AE3), S-100 protein, neuron specific enolase (NSE), and glial fibrillary acidic protein (GFAP). These findings, especially positive GFAP staining were characteristic and very helpful for the diagnosis of the rare tumor—malignant chondroid syringoma. Based on the previous reports, 39% of cases were found to have metastatic lesions and 22% died of this malignant tumor. There have been no reports reporting effectiveness of chemotherapy and radiotherapy, and an early wide excision with a broad margin may be the most reliable treatment to date. From the *Department of Dermatology, Keio University School of Medicine, Tokyo, Japan and the †Department of Dermatology, Kitasato University School of Medicine, Kanagawa, Japan. Reprints: Dr. Hayato Takahashi, Department of Dermatology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan (e-mail: firstname.lastname@example.org). © 2004 Lippincott Williams & Wilkins, Inc.