# Case report: Neuroendocrine carcinoma of the nasal cavity in a roe deer (Capreolus capreolus)

## TL;DR

A rare nasal neuroendocrine tumor was found in a roe deer, marking the first known case of this type of cancer in this species.

## Contribution

This is the first documented case of a neuroendocrine carcinoma in the nasal cavity of a roe deer.

## Key findings

- The tumor invaded multiple skull regions and formed distinct histopathological structures.
- Immunohistochemical analysis confirmed the diagnosis of neuroendocrine carcinoma.
- No prior cases of this tumor type in roe deer were found in database searches.

## Abstract

Neuroendocrine tumors of the nasal cavity are rare in both animals and humans. This report describes the macroscopic, histopathological and immunohistochemical characteristics of a neuroendocrine tumor in a three-year-old female roe deer (Capreolus capreolus) that was shot due to a facial deformity caused by an oval, firm, exophytic lesion effacing the left frontal and parietal regions. Longitudinal sectioning of the skull revealed a nasal cavity tumor that had invaded the cribriform plate, the rostral bones of the skull, the rostral aspect of the cranial cavity and the frontal sinuses and extended through the lacrimal, sphenoid and zygomatic bones into the subcutaneous tissue. Histopathologically, the tumor consisted of neoplastic cells forming sheets, nests, trabecular and cribriform structures separated by a delicate fibrovascular stroma. Mitoses were rare. Based on the histopathological and immunohistochemical findings, a neuroendocrine carcinoma was diagnosed. Based on thorough database searches, this is the first known case of a nasal neuroendocrine carcinoma in a roe deer.