Recurrent Inflammatory Intratarsal Keratinous Cyst Following an Incomplete Excision: A Case Report.

Intratarsal keratinous cyst (IKC) is a rare benign lesion arising within the tarsal plate that is frequently misdiagnosed as a chalazion. An IKC's incomplete excision often leads to multiple recurrences, but cases accompanied by acute inflammation or pain remain uncommon. We report a rare case of an IKC presenting with recurrent painful inflammatory episodes following incomplete surgical removal. An 80-year-old male presented with a firm, painless mass in his left upper eyelid. Eyelid eversion revealed a whitish lesion through the palpebral conjunctiva. Under the clinical diagnosis of a chalazion, an initial incision and curettage were performed; however, the cyst wall was not completely extirpated. The histopathological examination of the specimen confirmed IKC, showing no inflammatory cell infiltration or granulation tissue. Postoperatively, the patient experienced three painful inflammatory recurrences at the same site over a two-year period, each temporarily resolving with antimicrobial therapy. To achieve a definitive cure, complete surgical excision including the entire cyst wall was performed after the third recurrence. The histopathological analysis of the completely excised recurrent lesion revealed prominent inflammatory cell infiltration and granulation tissue formation surrounding the residual cyst wall. No recurrence has been observed for more than 12 months postoperatively. An incomplete excision of an IKC can trigger secondary inflammation and subsequent intractable, painful recurrences. Clinicians should consider IKC in the differential diagnosis of recurrent chalazion-like lesions, and a prompt histopathological evaluation with complete extirpation of the cyst wall is essential for a definitive cure.