Case Report: A rare and recurrent case of primary corneal keratosis: diagnostic and therapeutic challenges.

Background: Ocular surface keratosis typically presents as a focal, hyperkeratotic lesion. While commonly associated with actinic damage on the eyelid margin or conjunctiva, primary corneal involvement is exceptionally rare. Case presentation: A 32-year-old Asian female presented with a 10-year history of a recurrent white mass on the right cornea. Slit-lamp examination revealed a 3 × 3 × 4 mm, irregular, broad-based keratotic lesion at the nasal limbus, extending 1 mm onto the clear cornea. Anterior segment optical coherence tomography (OCT) confirmed superficial stromal infiltration. The patient had undergone prior surgical excision at an external hospital, followed by multiple recurrences. At our institution, conservative management with repeated mechanical debridement under slit-lamp guidance was performed. Histopathological analysis of the debrided material showed compact hyperkeratosis without cellular atypia, consistent with a benign keratotic lesion. Despite these interventions, the lesion demonstrated a consistent and rapid recurrence pattern, regrowing within 2-3 weeks after each debridement over a 12-month follow-up period. Conclusion: This case describes a rare presentation of primary recurrent corneal keratosis with benign histopathological features but clinically aggressive behavior. The rapid and persistent recurrence despite conservative management highlights the limitations of superficial debridement and suggests the presence of subclinical disease within the lesion base. This report underscores the need for long-term surveillance and consideration of more definitive treatment strategies for similar recurrent keratotic lesions on the cornea.