Ocular Surface Fibroma: Clinical, Histopathological, and Immunohistochemical Features of 10 Cases

Abstract

Aim: To describe the clinical, histological, and immunohistochemical (IHC) features of a series of 10 cases of ocular surface fibroma (OSF) and correlate the findings with other similar histological entities. Method: The patient demographics and features of the lesions were analysed from the clinical notes. All cases in the series had routine diagnostic excisional biopsies with standard histopathological and IHC evaluation. Each case was analysed by histology and immunohistochemistry with antibodies to: CD34, Factor XIIIa, desmin, smooth muscle actin, S100, Melan-A, β-catenin, neurofilament, and Ki67. Results: OSF occurred on the bulbar, tarsal, or forniceal conjunctiva, and typically presented as a white, pink, or yellow sheet-like or nodular lesion. The most common symptom was irritation or a foreign-body sensation. Lesions ranged in size from 4 to 13 mm. Only 1/10 cases showed a recurrence after an incomplete excision. Histologically, OSF comprised bland spindle cells in a collagen stroma. The spindle cells were CD34-positive (in 10/10 cases) and a smaller subset was positive for Factor XIIIa (6/10 cases). Normal resident spindle cells in the conjunctival stroma, Tenon’s capsule, and tarsal plate were positive for CD34 and Factor XIIIa, implicating these cells in the origin of OSF. Conclusion: OSF is a benign lesion of resident CD34- and Factor XIIIa-positive spindle cells in the conjunctiva and Tenon’s capsule. We have called to attention another lesion to be included by clinicians in the differential diagnosis of benign ocular surface lesions composed of CD34- and Factor XIIIa-positive spindle cells.