Safety of ultrasound-guided fine-needle aspiration of the feline pancreas: a case-control study

Comparison of ultrasonographic echogenicity and outcome in cats with suspected pancreatitis

OBJECTIVES

The aim of this study was to determine whether ultrasonographic pancreatic echogenicity, especially hypoechogenicity, has an impact on the prognosis of cats with suspected pancreatitis. We hypothesised that cats with a hypoechoic pancreas have a longer duration of hospitalisation, higher treatment costs and a higher mortality rate.

METHODS

This was a retrospective study, which included cats with clinical signs of pancreatitis, a SNAP fPL test result above the reference interval and ultrasonographic abnormalities consistent with pancreatitis. Medical records and follow-up information were retrieved from the local electronic database. Cases were assigned to one of three groups based on pancreatic echogenicity: hypoechoic, hyperechoic or mixed echogenicity. Statistical analysis aimed to assess differences in outcome, ultrasonographic abnormalities, historical features, physical examination findings, laboratory results, concurrent diseases or treatment costs.

RESULTS

Thirty-six (64%) cats with a hypoechoic, seven (13%) with a hyperechoic and 13 (23%) cats with a mixed echoic pancreas were included. Cats with a hypoechoic pancreas had a significantly lower median body weight (P = 0.010) and lower median body condition score (P = 0.004) compared with the other cats. Furthermore, they were presented as being lethargic significantly more often (P = 0.014), were more likely to have a homogeneously enlarged pancreas (P <0.001) and were less likely to have concurrent abnormalities or diseases, such as ultrasonographic enteric abnormalities (P = 0.020), triaditis (P = 0.013) and diabetes mellitus (P = 0.041). However, there was no difference in treatment costs (P = 0.961), duration of hospitalisation (P = 0.898), survival of hospitalisation (P = 0.419) or survival time (P = 0.256) between groups.

CONCLUSIONS AND RELEVANCE

In this study, echogenicity was of no prognostic value in cats with suspected pancreatitis. Cats with a hypoechoic pancreas were not associated with a poorer outcome than cats with a hyperechoic or mixed echoic pancreas.

ACVIM consensus statement on pancreatitis in cats

Background

Pancreatitis in cats, although commonly diagnosed, still presents many diagnostic and management challenges.

Objective

To summarize the current literature as it relates to etiology, pathogenesis, diagnosis, and management of pancreatitis in cats and to arrive at clinically relevant suggestions for veterinary clinicians that are based on evidence, and where such evidence is lacking, based on consensus of experts in the field.

Animals

None.

Methods

A panel of 8 experts in the field (5 internists, 1 radiologist, 1 clinical pathologist, and 1 anatomic pathologist), with support from a librarian, was formed to assess and summarize evidence in the peer reviewed literature and complement it with consensus clinical recommendations.

Results

There was little literature on the etiology and pathogenesis of spontaneous pancreatitis in cats, but there was much in the literature about the disease in humans, along with some experimental evidence in cats and nonfeline species. Most evidence was in the area of diagnosis of pancreatitis in cats, which was summarized carefully. In contrast, there was little evidence on the management of pancreatitis in cats.

Conclusions and Clinical Importance

Pancreatitis is amenable to antemortem diagnosis by integrating all clinical and diagnostic information available, and recognizing that acute pancreatitis is far easier to diagnose than chronic pancreatitis. Although both forms of pancreatitis can be managed successfully in many cats, management measures are far less clearly defined for chronic pancreatitis.

Is It Being Overdiagnosed? Feline Pancreatitis

In recent years, increased awareness of feline pancreatitis by the veterinary profession and improved diagnostic modalities have led to an increased frequency of diagnosis of pancreatitis in this species. Consequently, pancreatic diseases, especially chronic pancreatitis, are considered highly prevalent, even in populations of apparently healthy individuals. This prevalence has led to the suspicion that the condition may be overdiagnosed. This article summarizes the difficulties of diagnosis of acute and chronic pancreatitis, assesses the reasons why this is a challenging disease to recognize, and considers whether these difficulties could result in either overdiagnosis or underdiagnosis.

Suspected pancreatic carcinoma needle tract seeding in a cat

Case summary

A 15-year-old male neutered domestic longhair cat was referred for investigation of a pancreatic nodule. Fine-needle aspiration of the nodule was performed on two occasions, 2 weeks apart, and cytology revealed pyogranulomatous inflammation and moderately dysplastic exocrine pancreatic epithelium, suspicious for neoplasia. Thoracic radiographs were unremarkable and a partial pancreatectomy was performed. On histopathology, the nodule was diagnosed as a moderately differentiated pancreatic adenocarcinoma. Two weeks after surgery, a firm subcutaneous nodule was detected on the left ventrolateral abdomen. Cytology of the nodule was suggestive of pancreatic carcinoma and needle tract seeding was suspected. With palliative treatment, the cat lived a further 136 days.

Relevance and novel information

To our knowledge, this represents the first report of suspected transabdominal needle tract seeding of pancreatic carcinoma following fine-needle aspiration in veterinary medicine. Veterinarians should consider this when discussing risks of pancreatic fine-needle aspiration with owners and should attempt to minimise the number of needle aspirations where possible.

Feline abdominal ultrasonography: What's normal? What's abnormal? The pancreas

PRACTICAL RELEVANCE

Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. Ultrasound examination of the pancreas is a vital part of the investigation into feline pancreatic disease.

CLINICAL CHALLENGES

Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even for the experienced ultrasonographer, differentiating between incidental findings such as nodular hyperplasia and pathological changes such as neoplasia can be challenging.

AIM

This review, part of an occasional series on feline abdominal ultrasonography, discusses the ultrasonographic examination and appearance of the normal and diseased pancreas. Aimed at general practitioners who wish to improve their knowledge of and confidence in feline abdominal ultrasound, this review is accompanied by high-resolution images and videos available online as supplementary material.

EQUIPMENT

Ultrasound facilities are readily available to most practitioners, although use of ultrasonography as a diagnostic tool is highly dependent on operator experience.

EVIDENCE BASE

Information provided in this article is drawn from the published literature and the author's own clinical experience.

Diagnosis of insulinoma in a Maine Coon cat

Case summary

A 14-year-old male neutered Maine Coon cat presented with a 6-month history of polyphagia and one recent episode of tremors and weakness. Blood work revealed profound hypoglycemia and results of a paired insulin glucose test were consistent with an insulinoma. Abdominal ultrasound revealed a solitary pancreatic mass, and results of a fine-needle aspirate (FNA) gave further support for the location of the neuroendocrine tumor. After unsuccessful medical management of the hypoglycemia, the mass was surgically removed. Immunohistochemistry confirmed that it was an insulinoma. At the time of writing, the patient had been in clinical remission for 9 months.

Relevance and novel information

Feline insulinomas are rare and there is very little information on their behavior, clinical course and histologic characteristics. This is the first reported case of an insulinoma in a Maine Coon cat and the first to describe results of an ultrasound-guided FNA of the mass. In addition, the progression of disease, histopathology and immunohistochemistry results add to the currently minimal database for feline insulinomas.

Computed tomographic angiography and ultrasonography in the diagnosis and evaluation of acute pancreatitis in dogs

Background

Acute pancreatitis in dogs is an under‐diagnosed disease. Current diagnostic methods are insufficient at identifying sequelae and lack prognostic capability. Computed tomographic angiography (CTA) is accurate for diagnosis and prognostication of pancreatitis in humans.

Objectives

In comparison to ultrasound (US), CTA will (1) better diagnose more severe pancreatitis and sequelae and (2) provide assessment of patient outcome by identification of pancreatic contrast enhancement patterns.

Animals

Twenty‐six client‐owned dogs suspected to have acute pancreatitis.

Methods

US and CTA examinations performed at time of admission were compared to determine the detection of pancreatic changes and sequelae. CTA findings also were compared to outcome indicators for prognosis of dogs with acute pancreatitis. Specific canine pancreatic lipase (cPL) samples were obtained and compared with CTA findings.

Results

Ten of 26 dogs had heterogeneous contrast enhancement of the pancreas. Compared to US, CTA better identified portal vein thrombosis (P = .003). Patients with heterogeneous contrast enhancement had longer hospitalization (P = .01), including hospital stays for >5 days (P = .02), had more relapses, and were more likely to have portal vein thrombosis (P = .002). Patients with heterogeneous contrast enhancement had increased spec cPL (P = .006).

Conclusions and Clinical Importance

In comparison to US, CTA better identified dogs with more severe acute pancreatitis and those with portal vein thrombosis, factors that may predict longer hospitalization and increased risk of relapse. The presence of heterogeneous contrast enhancement and portal vein thrombosis may change therapy for patients with acute pancreatitis.