Conjunctival myxoid stromal tumor: Case series of a rare neoplasm

To report three cases of conjunctival stromal tumor (COST) with myxoid features and describe their microscopic characteristics and provide a review of the pertinent literature.

This case series consists of three patients who were found to have conjunctival growths consistent with conjunctival stomal tumors with myxoid features. Two patients underwent full excision without local recurrence, while one patient underwent local biopsy without post-procedure worsening of the lesion. All three cases demonstrated prominent myxoid stroma with spindle cell morphology and immunohistochemical staining with positive expression of CD34, and Factor XIIIa, and had negative immunoreactivity for S100 protein and smooth muscle antigen (SMA).

Conjunctival myxoid stromal lesions represent a rare growth affecting the bulbar conjunctiva, with less than 30 described cases since initial recognition as a distinct entity in 2012. These lesions are histologically characterized by a spindle cell morphology with variably prominent myxoid stroma and immunohistochemical positivity for CD34, factor XIIIa, and vimentin. Complete excision is the definitive treatment for these tumors, however incomplete resection or local biopsy may be reasonable given the clinically indolent behavior of these lesions and lack of recurrence or locally invasive disease as documented in the literature. Clinicians should maintain a low threshold to consider systemic evaluation given possible syndromic associations with conjunctival myxomas (CM), a lesion with markedly overlapping microscopic and immunohistochemical features with COSTs. Further characterization of these rare lesions will allow for greater diagnostic clarity and guidance regarding optimal management.