# Orbital Neurolymphomatosis in Patient with CNS Lymphoma

## TL;DR

This paper presents a rare case of orbital neurolymphomatosis in a patient with central nervous system lymphoma, highlighting the lacrimal gland as a potential biopsy site.

## Contribution

The study reports a unique case of neurolymphomatosis involving the orbit and cranial nerves in a patient with CNS lymphoma.

## Key findings

- Neurolymphomatosis was confirmed in the left orbit and cranial nerves II, III, V, and VI.
- Lacrimal gland involvement was histopathologically linked to the spread of CNS lymphoma.
- The lacrimal gland is proposed as an accessible biopsy site for suspected cranial nerve V involvement.

## Abstract

Neurolymphomatosis (NL) is a rare manifestation of hematologic malignancies, characterized by a neoplastic infiltration of the peripheral nervous system and cranial nerves (CNs). Non-Hodgkin lymphomas (NHLs) account for 90% of NL cases, while acute leukemia represents 10% of the cases. NL can occur as the first manifestation of a malignancy (primary), or as a relapse or progression of a previously treated disease (secondary). Herein, we report a unique case of NL involving the left orbit and CNs in a 74-year-old female with primary central nervous system (CNS) diffuse large B-cell lymphoma (DLBCL). Our patient developed secondary neurolymphomatosis involving the left orbit and CNs II, III, V, and VI, supported by clinical, radiologic, and histologic findings. The lacrimal gland enhancement was histopathologically proven to be caused by the direct spread of CNS DLBCL to the lacrimal nerve, a branch of CN V, identifying NL as one of the conditions that can affect this organ. The lacrimal gland could be considered as a more accessible biopsy site when the involvement of CN V is suspected.