# An Unusual Therapy for an Atypical Case of Secondary Extranodal, Non-parenchymal Central Nervous System Marginal Zone Lymphoma

## TL;DR

This paper presents a rare case of a slow-growing brain lymphoma treated successfully with high-dose chemotherapy.

## Contribution

The paper reports a novel treatment approach for a rare form of CNS lymphoma with an indolent course.

## Key findings

- Cavernous sinus involvement in marginal zone lymphoma is extremely rare.
- High-dose methotrexate and CHOP regimen effectively treated secondary CNS-MZL in this case.
- No standard treatment exists for indolent secondary CNS-MZL, highlighting the need for case-specific approaches.

## Abstract

Marginal zone lymphomas (MZL) are low-grade B-cell neoplasms with indolent clinical behavior and a favorable prognosis. Central nervous system (CNS) involvement is extremely rare in MZL, as in other low-grade lymphomas where some presented with primary CNS disease without involvement elsewhere, and only a few cases were secondary to MZL. The dura mater is the most common site of involvement, while cavernous sinus involvement is extremely rare. There are no specific treatment recommendations for patients with secondary CNS-MZL exhibiting an indolent course. Therapeutic trials and recommendations typically focus on aggressive lymphomas with a poor prognosis, where induction with intensive chemotherapy, including high-dose methotrexate and/or cytarabine, followed by autologous stem cell transplantation, is standard. We present the case of a 50-year-old man with MZL involving the cavernous sinus, who initially presented with neurological and ophthalmological symptoms and was successfully treated with high-dose methotrexate and the CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) regimen.