# Lymphomatoid Papulosis With DUSP22 Rearrangement in a Patient With a Historical Diagnosis of Primary Cutaneous Anaplastic Large Cell Lymphoma

## TL;DR

This paper reports a rare case of lymphomatoid papulosis with a specific genetic rearrangement in a patient previously diagnosed with a skin lymphoma.

## Contribution

The novelty lies in documenting a unique case of DUSP22-rearranged lymphomatoid papulosis in a patient with a prior diagnosis of primary cutaneous anaplastic large cell lymphoma.

## Key findings

- The patient exhibited a biphasic CD30 staining pattern typical of DUSP22-rearranged lymphomatoid papulosis.
- The case highlights the distinct clinical behavior of DUSP22-rearranged lymphomatoid papulosis compared to primary cutaneous anaplastic large cell lymphoma.
- The patient's condition showed regression without treatment, consistent with the indolent nature of this subtype.

## Abstract

Lymphomatoid papulosis (LyP) with DUSP22 rearrangement is an uncommon subtype of lymphomatoid papulosis featured histologically by two distinct patterns of epidermotropic cells, weakly CD30+ small- to medium-sized T-cells and a dermal infiltrate of strongly CD30+ medium- to large-sized T-cells. DUSP22 rearrangement is detected more frequently in anaplastic large cell lymphoma (ALCL) than in LyP. Primary cutaneous anaplastic large cell lymphoma (pcALCL) cases can also show a similar biphasic CD30 staining pattern. LyP with DUSP22 rearrangement has a more indolent clinical course than pcALCL and is more likely to regress without treatment. Herein, we report a unique case of LyP with DUSP22 rearrangement diagnosed in an 81-year-old female with a historical diagnosis of pcALCL, made 20 years prior.