"Jelly belly" is a rare mass effect on organs clinically presenting at surgery in selected cases of pseudomyxomaperitonei (PMP) [1]. On appearance, it is a gross collection of gelatinous material with a mucinous implant on peritoneal surfaces of organs within the abdomen or pelvis. Its origin is thought to arise from a collection of mucinous cells from a ruptured mucocele of the appendix or ovary, causing a localized PMP. These cells can take the form of hyperplasia or cystadenoma, or may more rarely occur as cystadenocarcinoma. The exact nature of this disease, whether it is considered benign or malignant, mucinous or pseudomucinous is still not settled. Patients may present with abdominal pain or increased girth, and “jelly belly” may be found incidentally. The gelatinous mass may be seen on CT scan, as the mucinous material has similar density to fat and appears heterogeneous. Of all mucoceles, 23%-50% are incidental findings during surgery. Mucocele is a rare clinical entity; the reported prevalence in appendectomy specimens at surgery is 0.2-0.3% [1].

The incidence of PMP has been described as one per two million per year [2], and the intra-operative presentation of "jelly belly" is thought to be even less common, although the exact incidence remains speculative. We report the case of abdominal "jelly belly" found intra-operatively in a woman who complained of chronic abdominal pain and increased abdominal girth.

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Figure 1. Well-encapsulated cystic mass in right lower quadrate, mass effect without inflammation and curvilinear wall calcification.

A 66 year-old female, with no previous medical history, was referred to the general surgery service by her primary care physician after suffering for two months from abdominal pain and increased abdominal girth. She denied nausea, vomiting, and diarrhea. She described the pain as diffuse, although with occasional emphasis in the right lower quadrant and right flank. On physical examination, mild abdominal tenderness was observed in the right lower quadrant, with no evident peritoneal signs. Vital signs were normal, and no fever was documented throughout the two months. Laboratory results returned normal. Abdominal ultrasound was unremarkable. The gynecological exam was normal.

The patient was referred to abdominal CT that demonstrated a 3*4 cm collection of fluid in the right lower quadrant, anterior to the cecum, and in the anatomic place of the appendix (Figure 1). A structure resembling the vermiform appendix was also visualized on CT, however posterior to the cecum, and not evidently inflamed. The CT picture elucidated a likely mucocele with a non-inflamed retrocecal appendix. After careful clinical consideration of the two-month-long history of abdominal pain, combined with the radiological report, the patient was taken to the operating theater. During exploratory laparoscopy, a gelatinous collection of roughly 6 cm in diameter - resembling a jellyfish – was found adhered to the anterior cecum.

This "jelly belly" was suctioned, and the cecum was examined. In the anatomical place of the appendix, which was hitherto covered by the "jelly belly," a small hole of 4-5 mm was discovered, which resembled the stump of the vermiform appendix. No appendix was to be found, however, in or around the cecum on exploration. No other pathology was noted in the laparoscopic procedure. The appendix stump was sutured without any complication, and the suctioned gelitanous material was sent to histopathological studies.

The post-operative period was uneventful. The cytological examination of the "jelly belly" revealed inflammatory/reactive cells only. No suspicious or malignant cells were found. At three months follow-up the patient felt perfectly well, and pain free.

PMP was first described by Werth in 1884 [3]. He ascribed PMP as a result of ruptured pseudomucineus cyst of the ovary. Later on, other sources of PMP were postulated, aside from ovarian or appendiceal (i.e.: cecal diverticula, dermoid cysts and gallbladder). The sequence of events that leads to formation of PMP from mucocele of the appendix most probably is a consequence of obstruction of appendicular lumen, most commonly by an appendicolith. Once the mucocele ruptures within the peritoneal cavity, a PMP is formed. The sequence of events, however, was emphasized in the experimental trail of Naeslund and Cheng [4], by ligation of rabbits’ appendices without interruption of blood supply to the organ.

In very few PMP presentations, a “jelly belly” is seen. This phenomenon is so rare that its incidence has not been reported in the literature.

In our case, the “jelly belly” was likely a result of the aforementioned Naeslund and Cheng mechanism: mucocele formation, rupture, and PMP implantation on the appeniceal stump. Tumor markers were negative, however, as was the pathological report-ruling out malignancy. On laparoscopic exploration, a solidified mass resembling a jellyfish was found, stuck on the anterior cecum. Intra-operatively, a small hole was found in the anatomical region of the vermiform appendix stump, which likely represents the origin of the PMP. Further, this hole was covered by the “jelly belly,” which was subsequently suctioned. The hole was sutured laparoscopically, and no vermiform appendix was found on exploration.

The diagnosis of PMP is made by US and CT, where CT is the modality of choice, and gives precise information about the exact location and the calcification of the progenitor mucocele. US shows a typical "onion skin" or target appearance - a heterogeneous cystic tubular mass with layering of the content, which correlates to the concentric pattern of the dense mucinoid material within the mass [6]. In our case, US was not diagnostic, and CT showed a mucocele with a retrocecal non-inflamed vermiform appendix. It is very odd, however, that the appendix was not seen on laparoscopic exploration, and possible theories of the “vanishing appendix” include autolysis of the appendix, or migration of the appendix once the appendiceal stump was compromised by the ruptured mucocele. Either way, the laparoscopic picture was very clear: a "jelly belly" with 6 cm diameter, stuck on the appendiceal stump, which was fully ruptured.

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Figure 2. Japanese sea nettle jelly fish.

The accepted therapeutic approach to PMP is to surgically remove the affected organ. Authors Fahim and Al Salamah [7] present a case of an 80-year-old female patient presenting with PMP secondary to an appendicular tumor leading to localized infiltration, and perforation of the cecal wall her clinical picture of acute abdomen, large bowel perforation. Right hemicolectomy and extensive resection of the tumor was performed in their case, due to the malignant nature of her pathological PMP. On the contrary, our case demonstrated a female patient with very mild symptoms of right lower quadrant abdominal discomfort; on CT, a fluid collection at the cecal area was shown; on histological exam no malignant cells were found. Suction of the gelatinous material revealed a perforation of the cecum proximal to the anatomical place of the appendix with no evidence to the appendix. Suction of the “jelly belly” and suturing of the appendix stump was chosen in our case as the appropriate approach to treatment, and the patient fully recovered. It could be reasoned further, that the “jelly belly” served as a protective “cap” to the ruptured cecum, preventing a possible acute abdomen, explaining the indolent clinical presentation in our case.

In conclusion, we describe an extremely rare case of a 66-year-old woman, who presented with acute abdominal pain. After careful inspection of CT scan revealing a mucinous collection in the right lower quadrant, laparoscopic exploration was performed, and a very peculiar presentation of “jelly belly” was discovered. It was cautiously suctioned, sutured, and found to be completely non-malignant. After surveying the literature, and exploring the possible mechanisms of this "jelly belly" formation, it was found that the conservative measures taken as described above resulted in the complete resolution of her symptoms. This patient will be followed for tumor markers and other signs of malignancy. In the meantime, she remains a very curious case of benign “jelly belly.”