# Lymphoma in European hedgehogs (Erinaceus europaeus): A case series

## TL;DR

This study reports five cases of lymphoma in European hedgehogs, highlighting clinical signs, tumor locations, and useful diagnostic markers.

## Contribution

The paper provides the first detailed case series of lymphoma in European hedgehogs with immunophenotyping data.

## Key findings

- Lymphoma in European hedgehogs commonly presented as skin masses in the cervical region.
- CD3, PAX5, and CD79a are reliable immunohistochemistry markers for lymphoma diagnosis in hedgehogs.
- T-cell lymphomas were identified in thymic and multicentric cases, while B-cell lymphomas were found in skin cases.

## Abstract

Neoplasia is rarely reported in European hedgehogs (Erinaceus europaeus). A retrospective search was conducted by contacting multiple veterinary diagnostic laboratories for cases of lymphoma in European hedgehogs. This resulted in 5 cases, from which clinical, gross, histologic, and immunophenotyping findings were recorded. Most animals (3/5) had skin masses involving the cervical region, 1 hedgehog had dyspnea and lethargy associated with hydrothorax, whereas another exhibited icterus and lethargy. The primary site of the lymphoma was the skin, particularly the neck or head (3/5), the thymus (1/5), and multicentric (1/5). Immunophenotyping confirmed B-cell lymphoma in 2 skin cases, a T-cell lineage for the thymic and multicentric cases, and undetermined for the remaining skin lymphoma. CD3, PAX5, and CD79a were reliable immunohistochemistry markers in formalin-fixed tissues in European hedgehogs. Although uncommon, lymphoma should be considered in the differential diagnosis for adult European hedgehogs with skin nodules, especially those seeming to originate from the neck.