# EBV-Positive Pleomorphic Variant Transformation of CD5-Negative Mantle Cell Lymphoma: A Rare Case Report and Literature Review

## TL;DR

A rare case of mantle cell lymphoma transformed into an Epstein-Barr virus-positive pleomorphic variant six years after initial diagnosis.

## Contribution

Reports a rare case of EBV-positive pleomorphic transformation of CD5-negative mantle cell lymphoma.

## Key findings

- CD5-negative mantle cell lymphoma transformed into EBV-positive pleomorphic variant after six years.
- Molecular studies confirmed the same clonal origin of the transformed lymphoma.
- Such transformation is rarely reported and has implications for diagnosis and management.

## Abstract

Mantle cell lymphoma (MCL) is a mature B-cell lymphoma associated with cyclin D family rearrangements and typically expresses CD5 and cyclin D1. Epstein–Barr virus- (EBV-) positive MCL is rare, and the role of EBV infection and its transformation in MCL remains unclear. We present a case of CD5-negative classic MCL that progressed to an EBV + pleomorphic MCL six years after the initial diagnosis. Molecular studies confirmed the same clonal origin. To the best of our knowledge, the EBV-positive transformation of CD5-negative MCL into a pleomorphic variant has rarely been reported, and its recognition is important for the diagnosis and the management of patients with MCL.