A conjunctival myxoid stromal tumor (COMST) mimicking phlyctenulosis: A case report and brief review of the literature

PURPOSE: This is a case report of a patient with a conjunctival myxoid stromal tumor (COMST), mimicking a phlyctenulosis. Tumors of the conjunctiva and cornea occupy a large spectrum ranging from benign lesions of myxoma to aggressive, life-threatening malignancies. Phlyctenulosis and phlyctenular keratoconjunctivitis are hypersensitivity reactions to a foreign antigen. OBSERVATIONS: A 64-year-old male presented with six-month history of non-painful lump in the conjunctiva of the left eye. It was a mobile, non-tender, non-ulcerated, non-hemorrhagic, non-pigmented lesion and was non-adherent to the sclera. The differential diagnosis of phlyctenulosis or a soft tissue tumor was considered. The lesion was completely excised. The microscopy showed an ill-defined hypocellular myxoid lesion composed of stellate and spindle-shaped cells with eosinophilic cytoplasm, containing round-ovoid and spindle-shaped nuclei with a vesicular chromatic pattern. The tumor cells were diffusely and strongly positive for vimentin and CD 34 and were negative for S100. The immunomorphological features were compatible with a conjunctival myxoid stromal tumor. Complete systemic evaluation excluded the possible association with systemic myxomas. CONCLUSIONS AND IMPORTANCE: Myxoid tumors of the conjunctiva are benign tumors, however, they can mimic other benign conditions like phlyctenulosis or more sinister lesions like malignant tumors. Therefore, it is important to do an excisional biopsy to ascertain the definitive pathology of an indeterminate conjunctival lesion. COMST may be the index presentation for the detection of previously undiagnosed myxoma syndromes. One such association is with cardiac myxomas, which can result in vascular embolic events. Therefore, it is important to do cardiac screening in all patients diagnosed with a COMST.