Subconjunctival Apocrine Hidrocystoma: A Rare Adnexal Tumor Mimicking a Parasitic Cyst

IntroductionApocrine hidrocystomas are benign cystic neoplasms arising from the secretory components of apocrine sweat glands. While commonly encountered as translucent nodules on the eyelid margin, where they originate from the glands of Moll, their presence within the subconjunctival space is exceedingly rare due to the absence of native apocrine glands in this tissue. The pathogenesis in such atypical locations is hypothesized to involve ectopic glandular tissue, post-traumatic implantation, or metaplasia [1-3].Clinically, a subconjunctival apocrine hidrocystoma can mimic a variety of more common entities, including conjunctival inclusion cysts, mucoceles, and, importantly, parasitic cysts, creating a significant diagnostic pitfall for clinicians. Definitive diagnosis relies on characteristic histopathological features—namely a bilayered epithelial lining with apical ”decapitation” secretion—which can be confirmed with a specific immunohistochemical profile [1, 4].Here, we report the case of a large, long-standing subconjunctival apocrine hidrocystoma in a young man, emphasizing the diagnostic journey from a clinical suspicion of a parasitic cyst to definitive immunohistochemical confirmation and successful management via complete surgical excision.