Q & A: Pancreatic Cyst in a Cat with Diabetes Mellitus

Ultrasound revealing pancreatic cyst
in a 10-year old diabetic cat

My patient is a 10-year old male neutered DSH that was treated for several years for diabetes mellitus. He went in to remission and was doing well until this summer. He was presented after having a "weird" episode after being in a room with an undiagnosed "toxin."

Physical examination revealed a palpable abdominal fluid wave and mild muscle wasting in the hindend. Blood work at that time revealed a mild evaluation in globulins but no other significant changes. 

An abdominal ultrasound revealed a hypoechoic pancreas with a large pancreatic cyst. No other abnormalities were noted. The effusion had an elevated total protein and cytology revealed very few cells with one macrophage that was suspicious for corona virus on IFA. A feline pancreatic lipase immunoreactivity (fPLI) concentration was elevated at 36.

He was treated with supportive care and improved over the next few weeks, the ascites resolved but the pancreatic cyst remains present. He was noted to have a ravenous appetite but no other clinical signs. a recheck fPLI had decreased to 6.5, a T4 was within normal limits, as was a serum trypin-like immunoreactivity (TLI) concentration. He has put more weight on after the owner increased his food ration. Over the past few weeks he has been doing well but the owner notes that he is licking smacking excessively and has loss some hair on the ventral tail and over the tarsus. We would appreciate your input on the case and your thoughts on aspirating the cyst.

Thank you in advance for your time and expertise.

My Response:

A pancreatic cyst is a rare finding in cats (1-4). In most cats, they are a benign incidental finding. the cysts can be associated with pancreatitis. It has been hypothesized that diabetes mellitus may develop secondary to a pancreatic cyst, but this does not appear to be the case with your cat inasmuch as the diabetes had been present for several years prior to the detection of the cyst.

In general, the treatment approach to a pancreatic cyst or pseudocyst involves everything from benign neglect if the cyst is small or the cat is asymtomatic, draining the cyst using an ultrasound guided procedure, or surgical removal, especially in cases where the cyst is large and quickly refills with fluid after drainage.

References:

1. Coleman MG, Robson MC, Harvey C.  Pancreatic cyst in a cat. N Z Vet J. 2005;53:157-159.
2. Branter EM, Viviano KR.  Multiple recurrent pancreatic cysts with associated pancreatic inflammation and atrophy in a cat. J Feline Med Surg. 2010;12:822-827.
3. VanEnkevort BA, O'Brien RT, Young KM. Pancreatic pseudocysts in 4 dogs and 2 cats: ultrasonographic and clinicopathologic findings. J Vet Intern Med. 1999;13:309-313.
4. Hines BL, Salisbury SK, Jakovljevic S, et al. Pancreatic pseudocyst associated with chronic-active necrotizing pancreatitis in a cat.  J Am Anim Hosp Assoc 1996;32:147-152.