Abstract

An adult male beaded lizard (Heloderma horridum exasperatum) was examined because of anorexia and lethargy of 1-week duration. Diagnostic testing included a physical examination, complete blood count, plasma biochemistry panel, whole body radiographs, and coelomic ultrasonography. A large palpable mass in the mid-coelom was confirmed by radiographs, and a smaller mass in the right lung was identified. Blood values were within reference ranges. The sonogram revealed a homogeneous mass with soft tissue echogenicity. Cytologic results from an ultrasound-guided fine needle aspirate were suggestive of a melanoma.

An exploratory coeliotomy was performed. The lizard was induced with propofol (PropoFlo, Abbott Laboratories, North Chicago, IL, USA; 5 mg/kg IV), an endotracheal tube was placed, and anesthesia was maintained with isoflurane (Isothesia, Abbott Laboratories, North Chicago, IL, USA; 2–3%). Artificial ventilation was provided at a rate of 2–3 breaths per minute. The large mass (10×5 cm diameter) originated in the right lung, with extensive adhesions to the right liver lobe. The smaller mass (2×3 cm diameter) was contained within the right lung. A right pulmonectomy and partial hepatectomy were performed to excise the tumors. Anesthetic recovery was uneventful. The lizard was prescribed butorphanol (Torbugesic, Fort Dodge Animal Health, Fort Dodge, IA, USA; 0.5 mg/kg IM SID for 7 days) and ceftazidime (Fortaz, Glaxo SmithKline, Research Triangle Park, NC, USA; 20 mg/kg IM every 72 h for five treatments).

Histopathologic evaluation of the mass confirmed the diagnosis of melanoma, and there was no evidence of neoplastic cells at the hepatectomy margin.