Case Study

Necrotizing Pancreatitis in a 10 year old FS Labrador Retriever dog

A 10-year-old FS Labrador Retriever was presented for acute onset of vomiting, anorexia, and lethargy of approximately two days. The physical exam revealed a tense right cranial abdomen and tacky mucous membranes. Initial blood work had shown elevated ALP activity, elevated amylase, elevated lipase, elevated BUN, and elevated cholesterol and hypokalemia. Blood work performed two days later showed an improvement in the amylase and lipase and normal CBC.

A 10-year-old FS Labrador Retriever was presented for acute onset of vomiting, anorexia, and lethargy of approximately two days. The physical exam revealed a tense right cranial abdomen and tacky mucous membranes. Initial blood work had shown elevated ALP activity, elevated amylase, elevated lipase, elevated BUN, and elevated cholesterol and hypokalemia. Blood work performed two days later showed an improvement in the amylase and lipase and normal CBC.

DX

Moderate, acute, suppurative, necrotizing pancreatitis.

Sonographic Differential Diagnosis

Pancreatitis with probable necrosis and sequestered tissue. Chronic active inflammation is likely given the mixed echogenicity of the tissue with irregular hyperechoic pancreatic changes suggestive for fibrosis and potential mineralization. Pancreatic neoplasia such as carcinoma cannot be ruled out and potentially suspected given signs of early mineralization (hyperechoic foci). The position of the pathology in the right limb and approaching the pancreatic base would predispose the patient to extra-hepatic common bile duct obstruction should bilirubin values begin to elevate.

Image Interpretation

Dramatic 5 x 7 cm mixed hypoechoic region of the right pancreatic limb is noted with hyperechoic ill-defined surrounding tissue consistent with saponification of fat (Image 1). A trace of free fluid is noted in the 11 O’clock position. Video of the same right pancreatic limb demonstrating the extension of the mixed hypoechoic pathology in a tubular shape that would help lead to suspect pancreatic origin (Video 1). Some small focal echogenic pinpoint changes are present at 3 O’clock that may represent early mineralization or fibrosis. Linear high resolution image of the same right pancreatic limb utilizing harmonics in order to filter interfering echoes and provide better detail to the image (Video 2). Power Doppler assessment of the right pancreatic pathology demonstrating strong central signals indicating primary blood flow to the region combined with areas devoid of Doppler signals leading to suspect regional necrosis or sequestrum (Video 3). Video demonstrating a 22-gauge US-guided fine needle aspirate (FNA) of the hypoechoic region of the pathology (Video 4). In this case the sonographer draws back on the syringe attempting to aspirate fluid in case of abscessation. Given that no coalesced fluid was present, the jab technique was then used without drawing back on the syringe in Video 5. The jab technique of the solid tissue is used to gently push the pathological cells into the needle hub; which is gently sprayed onto a slide. No aspiration actually occurs during sampling. Three days later after the cytology had been assessed, US-guided biopsy was performed to confirm the cytological interpretation and ensure no neoplasia was present (Video 6). The core biopsy needle is first seated into the pathology at the 2 O’clock position (hyperechoic focus just beneath the pancreatic capsule on the screen.) A 14-gauge 2.2 cm spring loaded core biopsy is taken of variable echogenicities within the pathology (Video 7). Note that the needle passes through both dramatically hypoechoic, mildly hypoechoic, and hyperechoic changes within the pancreatic limb in order to provide the pathologist with a variety of information (matched with the variety of sampled echogenicities) for the sample interpretation. The needle extends to a point 1cm proximal to the hyperechoic granulation bed in the far field at the 6 O’clock position to ensure that passage beyond the pancreatic capsule (buried under the hyperechoic bordering changes) does not occur. The pathology is unchanged post biopsy other than a slight interruption of the hyperechoic capsule in the near field where the biopsy needle entered the pancreas at the 12 O’clock position (Video 8). No free fluid is noted that would indicate post sampling hemorrhage immediately post biopsy nor after 5 minutes shown in Video 9. The sonographer applies direct pressure to any tissue that he samples by biopsy for approximately 3 minutes as a security measure to avoid excessive bleeding.

Outcome

The patient responded well to hospitalization and aggressive treatment for pancreatitis with pain management, plasma expansion, antibiotics and GI protectants. The patient was clinically normal at a 1-week follow-up. The amylase and lipase values normalized at a 14-day follow-up and the patient was clinically normal. 11 weeks later the patient presented with weakness and clinical signs consistent with pancreatitis/sepsis with elevated bilirubin values. The owners elected humane euthanasia at that point owing to poor quality of life from orthopedic and suspected recurrent pancreatic disease.

Comments

The elevated bilirubin in light of the position of the sampled pancreatic necrosis residing in the right pancreatic base would lead to the potential of post-hepatic obstruction as this patientвЂ™s potential final issue. This post-hepatic obstruction could not be confirmed through a recheck sonogram or postmortem examination. Technically, emerging neoplasia could have been present and not reflected in the FNA or biopsy samples. But this was not suspected given the patientвЂ™s strong clinical response and the fact that multiple regions of the pancreatic sonographic heterogeneity were sampled in both cases in order to ensure adequate areas of the pathology were reflected in the samples. Special thanks to Dr. Messina and staff at the Madison Animal Hospital, Madison, New Jersey, USA for their excellent management of this case and support of New Jersey Mobile Associates & SonoPath.com.

Clinical Differential Diagnosis

Pancreas – pancreatitis, pancreatic neoplasia. GI clinical signs- obstruction, neoplasia, intestinal perforation, infectious (viral, bacterial.)

Sampling

Cytology of fine-needle aspirates were performed and revealed active hemorrhagic pancreatitis. Biopsy of the pancreas revealed moderate, acute, suppurative, necrotizing pancreatitis.