Rectal duplication cyst in a 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.

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.

Successful Surgical Correction of Congenital Colonic Duplication and Anogenital Cleft in a Cat

A 17 wk old sexually intact female domestic shorthair kitten presented for an anogenital cleft and enlarged colon. The cat had experienced bacterial cystitis and constipation since weaning. Contrast referral images revealed an enlarged colon with a patent anus. Clinical examination revealed an anogenital cleft with a common anovulvar orifice. The rectum was patent upon digital rectal palpation, and fecal contamination of the vulva was present. Abdominal radiographs revealed two distinct colons, both filled with a moderate amount of formed fecal material. Contrast-enhanced computed tomography revealed segmental duplication of the descending colon with a dominant right colon and a smaller accessary left colon. The two structures conjoined at the transverse colon proximally and at the pubic brim distally. A common anogenital orifice with anovulvar communication was also noted. The anogenital cleft malformation was successfully repaired surgically. A celiotomy was performed to remove the smaller accessory colon. An ovariectomy and partial hysterectomy were also performed. The patient recovered uneventfully and showed no gross evidence of recurrent cystitis or urinary or fecal incontinence postoperatively. This is believed to be the first report of a congenital anogenital cleft and complete communicating colonic duplication in a cat.

Rectal duplication in an adult cat: a novel transanal surgical approach

CASE SUMMARY

A 3-year and 8-month-old male entire European domestic shorthair cat was presented with a history of recurrent rectal prolapse, straining and pain when defaecating. Previous non-surgical and surgical treatments had not provided a satisfactory result. Rectal prolapse had recurred within 2 weeks of treatment. Upon clinical examination, an intraluminal mass could be palpated rectally. A CT scan examination revealed the mass was of a cystic nature and the cyst was surgically excised via a transanal approach. On histological evaluation, the cyst walls consisted of three of the layers of normal rectum: mucosa, muscularis of the mucosa and submucosa. These findings led to the definite diagnosis of rectal duplication.

RELEVANCE AND NOVEL INFORMATION

Enteric duplication is among the differential diagnoses for straining and rectal prolapse in cats. This condition has previously been discussed in the veterinary literature, with a single case report describing a rectal duplication in a cat. In that particular case, the authors described a perineal surgical approach. Here we present a novel approach whereby the duplicated material was excised transanally in order to limit intra- and postoperative morbidity. The clinical outcome was excellent in our case, with complete resolution of clinical signs and no recurrence 18 months after surgery.

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.

Surgical resolution of an oesophageal duplication cyst causing regurgitation in a domestic shorthair cat

CASE SUMMARY

An 18-month-old female domestic shorthair cat was referred for investigation of a 6 month period of regurgitation. Contrast radiography indicated an intramural oesophageal structure. Ultrasound-guided fine-needle aspiration of the area retrieved viscous fluid containing high numbers of squamous epithelial cells. Computed tomography disclosed a thin-walled contrast-enhancing structure containing non-enhancing homogenous contents. Exploratory thoracotomy confirmed an intramural cystic oesophageal structure, which was resected. Histopathological analysis of the resected tissue demonstrated an intramural oesophageal duplication cyst. A 12 month follow-up period has seen complete resolution of the cat's clinical signs.

RELEVANCE AND NOVEL INFORMATION

This is the first report of successful oesophageal duplication cyst removal in a cat. Oesophageal duplication cysts should be included on the differential list for dysphagia and regurgitation in cats. Complete surgical removal in this cat carried a good long-term outcome.

Colonic cyst in a cat presenting recurrent constipation and abdominal pain

A 5-year-old domestic short-haired spayed female cat was presented for abdominal pain and suspended defecation. Abdominal radiographs confirmed constipation; abdominal ultrasonography showed a cystic oval structure attached to the colon. The structure exhibited a well-defined wall, composed of three layers. Its content was mildly echogenic and inhomogeneous. Laparotomy was performed and complete resection of the structure, and of part of the colon, was required (end-to-end anastomosis). Histopathology confirmed the structure to be a cystic formation of the colon with some areas of mucosal metaplasia. However the question whether the cystic structure was consistent with an intestinal duplication cyst - which is the most likely type of cyst in this particular case - a Meckel's diverticulum remnant, a vitelline duct cyst or a cystic diverticulum of the colon could not be resolved. Postoperatively, no further other episode of constipation occurred.

Malignant transformation of a duodenal duplication cyst in a cat

Case summary

A 15-year-old domestic shorthair cat presented for lethargy, vomiting and anorexia. Abdominal ultrasound showed a bi-lobed cystic duodenal mass. Based on ultrasonographic features, malignant transformation of a duodenal duplication cyst was suspected. A resection and anastomosis was performed. Histology of the mass was consistent with carcinoma and an intestinal mucosa was present along the inner surface of the mass, suggestive of a duplication cyst. The patient returned 3 months postsurgery with recurrence of clinical signs. Abdominal ultrasound showed a recurrent duodenal mass at the surgery site and body wall nodules. Fine-needle aspirates of these lesions showed epithelial neoplasia. Owing to the poor prognosis, the owners elected euthanasia.

Relevance and novel information

Malignant transformation of duplication cysts in cats is rare but can be detected on ultrasound. The described ultrasonographic features can aid in prioritization of malignant transformation of duplication cysts as a differential diagnosis.