Significant Osseous Metaplasia in a Chondroid Syringoma: A Case Report.

A chondroid syringoma is a rare primary benign skin adnexal tumor with distinct histomorphology. However, extensive metaplastic bone formation within the tumor can raise diagnostic concerns. Further, the eyelid is quite a rare site of involvement of this tumor. Herein, we report a case of a chondroid syringoma with metaplastic bone formation involving the right upper eyelid in a 60-year-old female patient. The Ki67 labeling index was low. On follow-up for 36 months, no recurrence was noted. Acquaintance with the diverse histomorphological and clinical presentation of this tumor can prevent major diagnostic pitfalls.