Solitary fibrous tumour of the conjunctiva: a rare presentation

A man in his early 50s presented with complaints of a painless, slow-growing mass in his right eye (OD) for 4 months. Examination of OD showed a well-demarcated, firm, subepithelial lesion on the temporal bulbar conjunctiva. Anterior segment optical coherence tomography (AS-OCT) revealed a compact-appearing, mildly reflective subepithelial lesion with back shadowing. Clinical differentials of benign reactive lymphoid hyperplasia and conjunctival lymphoma were considered and an excisional biopsy was performed. Histopathology revealed a cellular stromal tumour comprising spindle cells arranged in short fascicles. The Ki-67 index was 6%. Immunohistochemistry with signal transducer and activator of transcription 6 (STAT-6) showed moderate nuclear expression in lesional cells and giant cells. Correlating the histomorphology and STAT-6 positivity, a final diagnosis of conjunctival solitary fibrous tumour was made. Subsequent Ru-106 plaque radiotherapy was administered at a dose of 50 Gy to the site of the lesion. The patient was doing well with no signs of tumour recurrence at the 18-month follow-up. The novelty of this report lies in the illustration of AS-OCT findings, CD34-negative phenotype and the use of adjuvant Ru-106 plaque brachytherapy.