A rare case of acute abdomen

Abstract

Mesenteric cysts are tumoural formations which are generally benign in character, originate from the intestinal mesentery, and rarely cause abdominal tumours. They are asymptomatic unless a complication occurs, and thus may be incidentally diagnosed. Symptomatic cases may show up with findings such as abdominal pain, abdominal mass, nausea, and vomiting, and sometimes patients present with an acute abdomen. Treatment includes total excision of the cyst. We present the case of a male patient admitted to our emergency department with acute abdominal symptoms, who was subsequently found to have a mesenteric cyst measuring 30×20×9 cm.

Background

Mesenteric cysts are a rare cause of intra-abdominal masses, with an incidence in the general population of between 1/100 000 and 1/250 000.^1,2 Mesenteric cysts were first described by Benevienne, an Italian anatomist, in 1507.³ Mesenteric cysts are generally asymptomatic. The diagnosis in symptomatic cases is usually made incidentally, during laparotomies, or during radiological screening techniques performed for other reasons.⁴ Symptomatic cases may present with different clinical findings, such as abdominal pain, nausea, vomiting, abdominal swelling or mass.⁵ Mesenteric cysts may sometimes cause an acute abdomen, caused possibly by the pressure within and distension of the cyst, bleeding inside the cyst, torsion or perforation.¹ Mesenteric cysts originate from the mesentery of the small intestines (primarily from ileum, and then jejunum) in 80% of cases, and from colon mesentery in 20%. These cysts are generally benign in nature; malignancy is extremely rare.^2,6

Aetiology includes lymphatic system obstruction or ectopia, trauma and idiopathic reasons. There are a few theories about the mechanism of mesenteric cyst formation in the literature. Some of these theories are based on misplacement of the proliferated lymphatic tissue islets, which is caused by the lack of space for drainage; mechanical obstruction of the lymphatics; acceleration of the growth by trauma to lymphatics; the fusional defect of the mesenteric leaves; and the cystic development of the intestinal diverticules at the mesentery.² Omentum, retroperitoneal membrane and the total mesentery originate from the same embryological root, and these tissues include fat tissue, connective tissue, nerve, vessels, lymph and muscle tissues. The cysts that originate from these tissues are described as mesenteric cysts. Mesenteric cysts are divided into six groups. The cysts that are lymphatic or mesothelial in origin are seen mostly.^1,7 We discuss the case of a patient who presented with an acute abdomen and was treated with total excision of the cyst.

Case presentation

A 19-year-old male patient presented to our emergency department with worsening acute abdominal pain. At the initial examination, his abdomen was very sensitive and a mass was palpated that filled the right part of his abdomen. Rigidity and rebound were present at the right side of his abdomen. The vital signs were stable, and body temperature was 36.8°C. There was no air fluid level or free air evident at direct abdominal radiography, and while intestinal gas was present on the left side of the abdomen, on the right side there was no evidence of intestinal gas (fig 1). At abdominal ultrasonography, a multiloculated, 20×30 cm cyst with lobulated borders and evidence of vascularisation was detected; the cyst arose from the vicinity of the liver, extended inferiorly through the right side of the median abdominal line, and elongated into the pelvis. There was no free fluid in the abdomen. Abdominal computed tomography (CT) revealed a mass lesion, starting from the vicinity of the left liver lobe without a connection with the liver, filling the epigastric area and the lesser sac, at the location of the right Morison’s pouch, and along the right paracolic area, extending inferiorly towards the whole right abdomen. The mass measured 29×20×9 cm, and was multiloculated, hypodense, and did not show signal increase (figs 2–4). Apart from the mass, no other pathology was detected in the other intra-abdominal organs.

Figure 1.

Plain abdominal radiograph.

Figure 2.

Upper abdominal computed tomography (CT) scan.

Figure 4.

Middle abdominal CT scan.

Figure 3.

Pelvic abdominal CT scan.

Results of laboratory tests were: leucocytes 9.5×10³/μl, haemoglobin 13.2 g/dl, haematocrit 39%, platelets 217×10³/μl. C reactive protein concentration was 215 mg/l, and all biochemical parameters including amylase were within normal ranges.

The patient underwent surgery immediately. During explorative laparotomy, a large cyst measuring 30×20 cm, originating from the ascending colon’s mesentery, that started from the subhepatic region and extended to the superior region of the bladder, without a connection with the liver, and multiple cysts in the medial vicinity, ranging in size from 1–5 cm and with the same characteristics, were seen (fig 5). The ascending colon and the small intestines were moved to the left side of the abdomen, and the large cyst and the smaller ones were excised totally. No other abdominal pathology was detected. The patient was discharged from hospital at the sixth postoperative day, with no further problem. Histopathological examination revealed the cyst was a benign cystic mesothelioma.

Figure 5.

Perioperative image.

Discussion

Mesenteric cysts are rare formations that are usually asymptomatic, and can be seen at any age. Nowadays, a definitive diagnosis can be made using modern screening techniques—abdominal ultrasonography, CT or MRI are the most useful methods.⁸ The treatment of mesenteric cysts is total excision, with care taken during the procedure to prevent recurrence and possible malign transformation.⁹ Even though laparoscopic cystectomy cases have been reported in the literature, open surgery with total cystectomy is preferred mostly.⁹ This patient presented to our emergency department with acute abdominal pain, and underwent an urgent laparotomy which revealed that he had a giant mesenteric cyst originating from the right colon mesentery. The cyst was excised totally, and the patient was discharged on the sixth postoperative day. We think our patient’s acute abdominal pain was caused by capsular tension, due to fluid discharge into the cyst.

Learning points

• Mesenteric cyst is a rare cause of patients needing to undergo surgery because of an acute abdomen.

• An increase in the mesenteric cyst’s capsular tension should be remembered as a cause of an acute abdomen.

• Treatment is surgery, and the choice of operation is total excision in order to prevent recurrence and malign transformation.