Two Cases of STAT6-Positive, Primary Conjunctival Giant Cell-Rich Solitary Fibrous Tumour (Giant Cell Angiofibroma) with Some Unusual Histological Features

An 84-year-old male presented with a history of a slowly growing lesion beneath the right lower lid. Examination showed a right-sided mass in the inferior bulbar conjunctiva, measuring approximately 10 × 6 mm. The lesion was excised and showed a giant cell-rich solitary fibrous tumour (GCR-SFT) with pseudo-vascular spaces with benign cytology, with STAT6, expressed in the spindle, ovoid, and tumour giant cells. A second case, a 26-year-old white female, presented with a 12-month history of a grad ually expanding lesion in left inferior bulbar conjunctiva. Examination showed a well-defined, dome-shaped pink fleshy mass of 10 × 7 × 2 mm, on the inferior bulbar conjunctiva and abutting the inferior fornix. Excision followed by histology showed a similar appearance to the first case except tha t the multinucleate giant cells closely resembled Touton giant cells and did not show the rather hyperchromatic crowded nuclei of the giant cells observed in the first case. No pseudo-vascular spaces were identified. The tumour cells, including the Touton-like multinucleate giant cells, displayed nu clear positivity for STAT6. An unexpected feature was the presence of a Melan A- and Sox10-positive population amongst the GCR-SFT, postulated to be a subepithelial melanocytic nevus colliding with the GCR-SFT.Ocul Oncol Pathol
Source: Ocular Oncology and Pathology - Category: Opthalmology Source Type: research