[Bone tumours in lizards and snakes. A rare clinical finding]

This article presents the pathological findings of 13 bone and cartilage tumours in lizards (n=8) and snakes (n=5) within the clinical context.

Within a 12-year period (2001-2013), 13 cases of bone tumours in reptiles were diagnosed from 358 submitted tumour specimens. Pathological examination was performed on eight excisions, two biopsies, two amputates and four carcasses. Macroscopically, the samples displayed a light-coloured surface when cut and had a generally solid consistency. For the histological examination, representative specimens were decalcified when necessary, embedded in paraffin and stained using haematoxylin and eosin. Diagnosis was made based on the World Health Organisation classification for veterinary and human medicine.

Benign proliferations of the bone (ossifying fibroma [n=2], fibrous dysplasia [n=1]) as well as malignant cartilage (chondrosarcoma [n=2]) and bone tumours (fibroblastic osteosarcoma [n=2], small cell osteosarcoma [n=1]) were found on the head (n=5) and limbs (n=3) of various lizard species. In snakes only malignant cartilage neoplasms (chondrosarcoma [n=2], dedifferentiated chondrosarcoma [n=3]) of the spine were diagnosed. The histological appearance of the malignant tumours ranged from low to highly malignant differentiated aggregations of tumour cells, that produced varying amounts of osteoid or a hyaline matrix. Curative therapy was achieved in one ossifying fibroma by complete surgical removal and in two chondrosarcomas through amputation. No metastasis was observed in any of the four necropsies.

Primary neoplasias of the bone are rare tumours in reptiles. Considering the information on therapeutic procedures and clinical course, the therapy of choice in lizards is complete surgical removal whereas in snakes reductive surgery may prolong the survival time.