Dermatofibroma of the Eyelid: Immunohistochemical Diagnosis
A 66-year-old man developed a painless 2 mm to 3 mm recurrent nodule at the left upper eyelid margin. Excision disclosed a spindle cell lesion without frank atypia or mitotic activity growing in a twisted fascicular pattern often referred to as storiform. All the surgical margins were involved with tumor. Immunohistochemistry demonstrated that many of the constituent spindle and dendritic tumor cells were CD34−, factor XIIIa+, and CD 163+, the latter 2 being biomarkers for monocytic lineage. The lesion was diagnosed as a dermatofibroma rather than a fibrous histiocytoma, a term that should be reserved for more aggressive lesions of deeper fascial planes. Facial dermatofibromas are rarer and more likely than those of the extremities to recur and therefore deserve wider local excision at first surgery with careful and frequent clinical follow ups. Eyelid dermatofibroma has probably often been misdiagnosed as another tumor in the past. Immunohistochemistry can supply valuable biomarker criteria for diagnosis.