IMAGING DIAGNOSIS-RADIOGRAPHIC, ULTRASONOGRAPHIC, AND COMPUTED TOMOGRAPHIC CHARACTERISTICS OF A DUODENAL DUPLICATION CYST IN A YOUNG CAT

Colonic duplication cyst with secondary septic peritonitis in a cat

Case summary

A 5-month-old male castrated domestic shorthair cat was evaluated for acute onset of emesis. Abdominal radiographs identified a suspected colonic foreign body and abdominal-focused assessment with sonography for trauma, triage and tracking (AFAST) evaluation revealed a large amount of peritoneal effusion. Cytology of the peritoneal effusion was consistent with a septic exudate. An exploratory celiotomy identified a ruptured ileocecocolic mass and a resection and anastomosis was performed. No foreign material was identified and histopathology confirmed that the ruptured mass was a colonic duplication cyst. Recurrent septic peritonitis was diagnosed based on cytologic evaluation of fluid from a silicone bulb reservoir of a closed suction drain. No abnormalities were surgically identified, the cat recovered without complication, was discharged at 7 days postoperatively and has continued to remain healthy 8 months after surgical intervention.

Relevance and novel information

To our knowledge, this is the first known instance of a histopathologically confirmed non-communicating colonic duplication cyst causing septic peritonitis in the veterinary literature.

Case report: Surgical management of ileal duplication cyst in a cat: a case report and review of the literature

A 6-year-old castrated, mixed breed cat presented with vomiting, anorexia, and lethargy. Ultrasonography and computed tomography revealed a round, well-marginated structure closely associated with the ileum proximal to the ileocolic junction. Exploratory laparotomy revealed a mass originating from the distal end of the ileum, close to the ileocolic junction. The mass did not interact with the intestinal lumen. Excisional biopsy with omentalization was performed without small intestinal resection to preserve the ileocolic junctions. Histopathological examination confirmed the presence of an enteric duplication cyst. The cat recovered uneventfully from surgery and remained asymptomatic postoperatively. No recurrence was identified 4 months after surgery. Enteric duplication cysts are uncommon congenital anomalies that originate in the gastrointestinal tract. They could either be communicating or non-communicating with the intestinal lumen. Enteric duplication cysts can be symptomatic or asymptomatic. Enteric duplication cysts associated with the esophagus, duodenum, and jejunum have also been reported in cats. However, to the best of our knowledge, this is the first reported case of an enteric duplication cyst in the feline ileum. Thus, enteric duplication should be considered a differential diagnosis in cystic masses of the ileum.

Preliminary study of CT features of intermediate- and high-grade alimentary lymphoma and adenocarcinoma in cats

CASE SERIES SUMMARY

The ultrasonographic findings of many feline intestinal tumours are similar. This study evaluated the CT features of intermediate- and high-grade alimentary lymphoma and adenocarcinoma in cats. CT was performed on six cats with adenocarcinoma and 14 cats with lymphoma. Comparisons between tumour types were conducted, focusing on CT features, including obstruction (present or absent), growth patterns of lesions (symmetry or asymmetry), layering enhancement (present or absent), location of the lesion, number of lesions (solitary or multiple), lymphadenopathy (present or absent), location of lymphadenopathy, pulmonary metastasis (present or absent) and maximum thickness (mm) of the lesion. The cats with adenocarcinoma (n = 5/6 [83%]) experienced intestinal obstruction significantly more often than cats with lymphoma (n = 0/14 [0%]; P = 0.0004). Layering enhancement was observed significantly more often in cats with adenocarcinoma (n = 6/6 [100%]) than in cats with lymphoma (n = 1/14 [7%]; P = 0.0002). Lymphadenopathy was detected significantly more often in cats with lymphoma (n = 14/14 [100%]) than in cats with adenocarcinoma (n = 2/6 [33%]) (P = 0.003). In cats with lymphoma, the intestine (12.1 ± 3.9 mm) was significantly thicker than that in cats with adenocarcinoma (6.4 ± 2.3 mm; P = 0.005).

RELEVANCE AND NOVEL INFORMATION

To the best of our knowledge, no reports have described the characteristics of feline intestinal tumours using CT. Layering enhancement was observed in cats with intestinal adenocarcinomas. No layering enhancement was observed in alimentary lymphoma in cats, but enlarged regional nodes were noted. Lesions with lymphoma were thicker than those with adenocarcinoma. These findings may help differentiate between adenocarcinomas and lymphomas.

Asymptomatic Enteric Duplication Cyst in a Geriatric Cat: Case Report and Review of the Literature

An 11 yr old female neutered domestic shorthair presented for an 8 mo history of an asymptomatic abdominal mass. Computed tomography described an irregular, cystic structure closely associated with the duodenum, and focal ultrasonography confirmed the mass shared outer layers with the intestinal wall. Coeliotomy revealed the mass was originating from, and firmly adhered to, the antimesenteric border of the duodenum but was not communicating with the intestinal lumen. En bloc mass resection with omentalization was performed without small intestinal resection. Histopathology confirmed an enteric duplication cyst. The cat made a full recovery and remained asymptomatic postoperatively with no evidence of recurrence. A review of the literature confirms the duodenum to be the most common location of enteric duplication cysts in felines and that subtotal excision is curative in most cases. This differential should be considered in cases of cystic gastrointestinal structures in juvenile and adult felines, with or without associated clinical signs. In cases of luminal involvement or malignant transformation, intestinal resection and anastomosis is more appropriate. This report describes the presentation, investigations, and treatment of an asymptomatic duodenal duplication cyst in an adult feline and summarizes and compares current knowledge of the condition between veterinary and human literature.

Feline abdominal ultrasonography: What's normal? What's abnormal? The diseased gastrointestinal tract

PRACTICAL RELEVANCE

Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. B-mode ultrasonography is likely the most widely used modality for imaging the gastrointestinal (GI) tract in cats and it can help in the diagnosis of GI masses, foreign bodies and disorders of the ileocaecocolic junction.

CLINICAL CHALLENGES

Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even differentiating between normal variations and pathological changes can be challenging for all but the most experienced. For example, while for inflammatory conditions of the feline GI tract changes are frequently identified on ultrasound, there may occasionally be no changes to the appearance of the intestine; hence a 'normal' ultrasound does not exclude the possibility of inflammatory disease.

AIM

This review, part of an occasional series on feline abdominal ultrasonography, describes the appearance of a range of conditions that affect the feline GI tract; the normal GI tract is addressed in an accompanying article in this issue of JFMS. Aimed at general practitioners who wish to improve their knowledge 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.