Solitary fibrous tumor of the caruncle: a solitary location

A 78-year-old Caucasian male presented with diplopia and decreased vision in the left eye for 1 month, in addition to a painless fleshy lesion in the inner corner of the left eye for 3-month duration. His best-corrected visual acuity was 20/40 and 20/50. Slit lamp examination revealed a left medial conjunctival and caruncular lesion, measuring 6 mm by 4 mm. Histology of the excised mass showed a cellular submucosal spindle cell neoplasm without cytologic atypia and rare mitoses, immunohistologically diffusely positive for CD34 and STAT6, and negative for SMA. Based on these findings, solitary fibrous tumor was diagnosed. With the combined diagnostic power of light microscopy and immunohistochemistry, SFTs are diagnosed increasingly and more accurately in the orbit. With this first case report of a caruncular SFT, we believe that SFTs should remain on the differential for mesenchymal tumors of the conjunctiva and caruncle.