A Case of Leukemic Phase of Mantle Cell Lymphoma Diagnosed With Scarring Conjunctivitis and Bilateral Upper Palpebral Conjunctival Tumor.

PURPOSE: Mantle cell lymphoma (MCL) is an aggressive B-cell non-Hodgkin's lymphoma. Ocular adnexal involvement is rare as the initial symptom, and conjunctival involvement is particularly rare. METHODS: An 84-year-old man was referred to our hospital with chronic conjunctivitis of the bulbar and tarsal conjunctiva with bilateral symblepharon, as well as a reddish-brown, cobblestone-like tumor. RESULTS: Suspecting malignancy, a tumor biopsy and systemic examination revealed the neoplastic lesion to be MCL. Leukocytosis and abnormal cells in peripheral blood (53%) were observed, and diffuse tumor cell infiltration was observed in the bone marrow. Both the bone marrow and tumor cells were positive for CD5, CD20, and cyclin D1, while the bone marrow tissue was negative for SOX11, confirming leukemic conversion (leukemic phase of mantle cell lymphoma). PET/CT revealed accumulation in systemic lymph nodes and extranodal organs, leading to a diagnosis of Ann Arbor stage IV disease. TP53 deletion was not detected. Following treatment with acalabrutinib in combination with bendamustine and rituximab, as reported in 2025, the conjunctivitis and eyelid tumor resolved, with no recurrence observed during follow-up. CONCLUSION: We report a case of leukemia-type MCL diagnosed with bilateral chronic cicatricial conjunctivitis and elevated lesions on the upper eyelid conjunctiva as initial findings. When encountering such findings, early pathological diagnosis and thorough systemic examination are important, with systemic malignant lymphoma in mind.