Hypoglycemia in Four Dogs With Smooth Muscle Tumors

Abstract

Tumor-associated hypoglycemia has been reported in dogs with pancreatic beta-cell tumors, hepatic tumors, and, rarely, with other neoplasms. This article describes 4 dogs with marked hypoglycemia associated with smooth muscle tumors (jejunal leiomyoma, gastric leiomyoma and leiomyosarcoma, and splenic leiomyosarcoma). Presenting clinical signs included grand mal seizures, lethargy, weakness, ataxia, and, in 1 dog, polyuria/polydipsia. The serum insulin concentration was low in 1 dog and normal in the other dog evaluated. Immunohistochemical staining for insulin was negative in the 4 tumors; the 3 tumors arising from the stomach and jejunum stained diffusely positive for glucagon. Blood glucose concentrations rapidly returned to normal after complete surgical resection of the tumors, and clinical signs associated with hypoglycemia resolved. Long-term follow-up available in 3 of the 4 dogs found no recurrence of clinical signs related to hypoglycemia at 15, 31, and 38 months after surgery, respectively.

Hypoglycaemia as a Paraneoplastic Syndrome Associated with Renal Adenocarcinoma in a Dog

“…In this case, therapy with intravenous 5% glucose infusion and glucocorticoids that improve glycogenolysis and gluconeogenesis permitted complete control of the clinical signs. Survival times are excellent in dogs treated surgically when a benign tumour is present: blood glucose concentration rapidly returns to normal after complete resection of smooth-muscle tumours and a favourable long-term prognosis is described (Beaudry et al, 1995;Boari et al, 1995) in the absence of metastasis.…”

Beta-Cell Neoplasia: Insulinoma

“…Proposed mechanisms include excessive glucose utilization by the tumor, impaired hepatic glycogenolysis and gluconeogenesis as a result of tumorinduced hepatic destruction or inhibition of normal counterregulatory responses that prevent hypoglycemia, and secretion of an insulin-like molecule, specifically insulin-like growth factor-2 (IGF-2) that lowers the blood glucose concentration by enhancing glucose utilization by normal cells (Cryer and Polonsky, 1998). Serum insulin concentrations are typically undetectable or in the lower end of the reference range with non-betacell tumors, in contrast to the high-normal to increased serum insulin concentrations seen with hypoglycemia induced by a betacell tumor (Beaudry et al, 1995;Bagley et al, 1996;Bellah and Ginn, 1996). IGF-2 is structurally homologous to proinsulin, can bind to insulin receptors, and has direct insulin-like actions that result in hypoglycemia (de Groot et al, 2007).…”

Paraneoplastic Hypoglycemia Due to an Insulin‐Like Growth Factor Type‐II Secreting Hepatocellular Carcinoma in a Dog

“…In canines, paraneoplastic hypoglycemia is associated with a variety of tumors of both epithelial and mesenchymal origin with the latter being most common. [3][4][5] Leiomyosarcoma and leiomyoma of the gastrointestinal tract and liver are the most frequent mesenchymal tumors, [3][4][5] but also splenic hemangiosarcoma has been described. 3 Among the epithelial tumors, liver carcinoma is most common.…”