A 7-yr-old female iguana with a 1-yr history of inappetence, lethargy, heterophilia (27,600
mm3), and elevated phosphorus (>16.1 mg/dl) and uric acid (9.8 mg/dl) levels was presented for progression
of clinical signs. Laboratory results revealed a WBC of 15,000 mm3 and phosphorus, CPK, and uric acid levels of
22.6 mg/dl, 6390 I/L and 13.9 mg/dl, respectively. Radiographs were unremarkable. The animal died shortly after admission.
Gross necropsy showed enlarged pale kidneys and a mottled tan/brown liver. Sections of liver, kidney and bone marrow were
submitted for histologic evaluation.
The bone marrow contained a highly cellular infiltrative mass that had effaced normal histologic
architecture. The mass was composed of sheets of round cells that had basophilic, vesicular, usually eccentric nuclei;
scant pale basophilic cytoplasm and distinct cell borders. Mitoses (1-3/hpf) were observed. Similar neoplastic infiltrates
were effacing 90% and 75% of the kidney and liver histologic architecture, respectively. Additionally, only ghosts of
glomeruli were observed in the kidney and the scattered remaining renal tubules were dilated.
These findings are consistent with disseminated immunoblastic leukemia. Similar tumors have been
reported in a Savannah monitor,4 giant snake,1 rhinoceros viper and Eastern and California king
snakes.3,2 Intranuclear virus-like inclusions were observed in tumor cells in the California king
snakes.2 Electron microscopic examination of tumor cells in this iguana did not reveal any structures known to
be consistent with virus particles.
1. Frank W, A Schepky. 1969. Metastasizing lymphosarcoma in a giant snake, Eunectes
murinus. Pathol. Vet. 6(5):437-43.
2. Jacobson ER, JC Seely, MN Novilla. 1980. Lymphosarcoma associated with virus-like
intranuclear inclusions in a California king snake (Colubridae: Lampropeltis). J. Natl. Cancer Inst.
3. Jacobson E, MB Calderwood, TW French, W Iverson, D Page, B Raphael. 1981. Lymphosarcoma
in an Eastern king snake and a rhinoseros viper. J. Am. Vet. Med. Assoc. 179(11):1231-5.
4. Schultze AE, GL Mason, VL Clyde. 1999. Lymphosarcoma with leukemic blood profile in a
Savannah monitor lizard (Varanus exanthematicus). J. Zoo Wildl. Med. 30(1):158-64.