Ultrasound-aided diagnosis of an insulinoma in a cat

Abstract

A 15-year old, neutered female, domestic shorthaired cat was presented for evaluation of a 3-month history of paroxysmal falling over and trembling. In laboratory work the cat displayed a mild hypoglycemia. Ultrasound revealed a nodule in the left pancreatic lobe and surgical excision was performed. The histological diagnosis was an insulinoma. To the authors knowledge this is the first ultrasound description of an insulinoma in a cat. Up to date the cat has a survival time of 32 months without recurrence of symptoms.

Retrospective study of 20 cats surgically treated for insulinoma

“…No predilection for age, sex, breed, or body weight was statistically significant in our population. The majority were older domestic cats presenting with neurologic signs (all hypoglycemic and 92.3% had inappropriate serum insulin concentrations), consistent with prior INS case reports 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 and canine INS publications. 10 , 21 , 22 Metastasis was noted as an important factor influencing DFI and DRD.…”

“…19 All of the previous case reports were cats with stage I disease. 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 Similar findings were noted in 2 larger canine studies in which pathologic stage was a predictor of survival time. 10 , 22 The authors of a recent report on the outcome of 48 dogs surgically treated for INS concluded that stage I disease MST was 652 days (range: 2‐1680) and stage II/III disease MST was 320 days (range: 1‐1260).…”

“… 17 In 1974, 2 more cases of primary FICT were identified using the Veterinary Medical Database (VMD). 18 Since then, there have been 8 published case reports of INS, 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 and 2 online institutional case submissions. 19 , 20 The 20 cats reported in this study include 1 of these case reports 7 and online case submissions.…”

“… 1 There remains a paucity of information in the veterinary literature regarding feline INS, with 8 cats reported from 1985 to 2020. 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 Of these 8 cases, ages ranged from 12 to 17 years, 6 were castrated males and 2 spayed females, 4 domestic shorthairs, 3 Siamese, and 1 Maine coon.…”

“…For the previous 8 case reports of INS, 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 survival times ranged from 3 days to more than 35 months. One cat was euthanized 18 months after surgical removal of the tumor and postmortem examination performed identified metastasis to the pancreatic lymph nodes and liver.…”