Nodular Fasciitis of the Orbit: A Case Report Confirmed by Molecular Cytogenetic Analysis.

Nodular fasciitis is a benign fibroblastic proliferation typically found in the subcutaneous tissue or superficial fascia of the extremities that is often confused for malignancy. These lesions rarely occur on the eyelids and ocular adnexa and are seldom analyzed by ophthalmic pathologists. USP6 gene rearrangement has been recently demonstrated in nodular fasciitis and this rearrangement may lead to the formation of a fusion gene MYH9-USP6 in some cases. Herein, the authors describe a 38-year-old woman with a 6-month history of a progressively enlarging mass beneath her right medial upper eyelid. Histopathologic analysis of the excisional biopsy confirmed classic features of nodular fasciitis. Molecular cytogenetic analysis revealed a rearrangement of the USP6 locus, confirming the diagnosis of benign nodular fasciitis.