Medical management of gastrinoma in a cat

Abstract

Case summaryA 7-year-old male castrated domestic short-haired cat was evaluated for a 4 week history of intermittent vomiting, ptyalism, lethargy and weight loss. Serum biochemistry revealed mild mixed hepatopathy. Abdominal ultrasonography identified multiple heterogeneous hepatic masses and a linear, hyperechoic focus with associated reverberation artifact in the wall of the stomach consistent with a gastric ulcer. Serum gastrin concentrations were markedly increased. Cytologic interpretation of a fine-needle aspirate of the hepatic masses was consistent with neuroendocrine neoplasia, and a diagnosis of gastrinoma was established. Deterioration of the cat’s condition, despite at-home acid-suppressant therapy, led to hospitalization. The cat was initially stabilized with intravenous crystalloid fluid therapy, maropitant, pantoprazole and octreotide. A continuous radiotelemetric intragastric pH monitoring system was used to monitor the response of intragastric pH to therapy. Long-term therapy was continued with omeprazole (orally q12h), octreotide (subcutaneously q8h) and thrice-weekly toceranib administered orally. Toceranib therapy led to gastrointestinal upset and was discontinued. Gastric ulceration resolved within 8 weeks, and palliation of clinical signs was achieved for approximately 5 months.Relevance and novel informationIncluding this report, only six cases of feline gastrinoma have been reported in the veterinary literature. Little is known regarding non-surgical therapy, and octreotide has not been previously reported for medical management of feline gastrinoma. Results of intragastric pH monitoring and clinical improvement suggest that medical therapy using octreotide and proton pump inhibitors represents a novel therapeutic option for cats with gastrinoma where surgical excision is not feasible.

Evaluation of Gastric pH and Serum Gastrin Concentrations in Cats with Chronic Kidney Disease

“…A pH monitoring capsule was detached from its delivery device and was administered PO with a syringe‐style pet piller as previously described and followed by PO administration of 3–5 mL of water. Before use, all pH capsules and receivers were calibrated as previously described according to the manufacturer's instructions .…”

Combined surgical and medical management of a cat with gastrinoma

“…Gastrinomas are rare neuroendocrine tumours in cats. To date, this is only the seventh case report of a feline gastrinoma in the literature, and the only cat treated with combined surgical and medical therapy consisting of toceranib and omeprazole (Middleton et al 1983, Liptak et al 2002, Diroff et al 2006, Lane et al 2016. This patient achieved the longest reported survival time in a cat at more than 35 months.…”

“…Several reports have described exclusive medical management for feline and canine gastrinoma (Middleton et al 1983, Van der Gaag et al 1988, Diroff et al 2006, Lane et al 2016. In all cases, acid suppressant therapy was used.…”

“…Somatostatin analogues, such as octreotide, have also been used in both dogs and cats (Altschul et al 1997, Lane et al 2016. A large concentration of high-affinity somatostatin receptors is present in greater than 90% of human gastrinomas.…”

“…Diagnosis of gastrinoma requires the presence of a neuroendocrine tumour (most commonly pancreatic in origin), hypergastrinaemia and gastrointestinal ulceration. Given the rarity of this disease in cats, only six feline cases have been reported in the literature (Middleton et al 1983, Liptak et al 2002, Diroff et al 2006, Lane et al 2016. Due to this, there has been no consensus with regard to the ideal treatment approach or median survival time.…”