Rhabdomyosarcoma in a terrestrial tortoise (Geochelone nigra) in Nigeria: A case report

Abstract

A skeletal muscle tumour (rhabdomysarcoma) was diagnosed in a 4-year-old captive female
terrestrial tortoise (Geochelone nigra) weighing 7 kg presented at the Veterinary Teaching
Hospital, University of Ibadan, Ibadan, Nigeria. The tumour was located at the anterior right
portion of the body and ventral to the carapace. The location of the tumour prevented the
tortoise from extending its head from the body. The tumour was a sessile, smooth white
mass, with a soft myxomatous consistency. The histological features that were diagnostic of
rhabdomyosarcoma included a sparse population of haphazardly arranged spindle-shaped
cells within a homogenous matrix (anisocytosis), occasional tumour giant and binucleate
cells, and some well differentiated myofibrils with cross striations within the cytoplasm. The
paucity of information on tumours in the land tortoise was the reason for this report, which
appears to be the first report of rhabdomyosarcoma in the tortoise.