# Sarcoma at the Site of a Transponder Implant in a Standing’s Day Gecko (Phelsuma standingi): A Case Report

## TL;DR

A gecko developed a tumor near a microchip implant, raising concerns about possible links between implants and cancer in reptiles.

## Contribution

This is the first reported case of a transponder-associated sarcoma in a reptile.

## Key findings

- A sarcoma was found surrounding a passive integrated transponder in a gecko.
- The tumor invaded muscle, fat, and bone near the implant site.
- A causal link between the transponder and the tumor could not be confirmed.

## Abstract

A 26‐year‐old female Standing’s day gecko (Phelsuma standingi) was presented for evaluation of a mass on the right caudolateral trunk and was subsequently euthanized. Necropsy revealed a neoplastic mass surrounding a passive integrated transponder at the body wall. Histopathology of the mass was consistent with a sarcoma and was characterized by whorls of fusiform neoplastic cells invading the muscle, adipose, and bone of the coelomic wall. Given its proximity to the transponder and the degree to which it encompassed the device, the sarcoma was inferred to be transponder‐associated. However, further conclusions regarding a causal relationship between the transponder implant and the neoplastic mass cannot be drawn based on this single case. This report describes the clinical presentation and pathologic findings for a microchip‐associated neoplasia in a reptile.