Abdominal pseudocyst case reports

A 21-year-old male with hydrocephalus and bilateral VPS presented with a right-sided shunt malfunction. After a routine Abdominal ultrasonography (US), that proved to be unremarkable, the patient had a clinical and radiological improvement followed by a relapse. An abdominal computed tomography scan subsequently showed an APC around the peritoneal catheter tip. Laparoscopic intervention on the APC cured the shunt malfunction. We believe that the APC emptied during the compression involved while performing the abdominal US. The pseudocyst collapse led to missing it on the abdominal US and explains the short-lived clinical and radiological improvement. We introduce the concept of APC-related variable VPS function, discuss the possible mechanisms by which the pseudocyst deflated, and make suggestions for this diagnostic problem. Key Messages: A collapsible abdominal pseudocyst could result in a variable ventriculoperitoneal shunt function. Starting the abdominal ultrasound examination over the location of the peritoneal catheter tip may overcome the collapse. Contrasted computed tomography is superior to ultrasound in diagnosing the pseudocyst ¹⁾

A 30-year-old woman with abdominal distension, vomiting and confusion caused by her developing an abdominal CSF pseudocyst, 13 years after her last shunt revision ²⁾

In 1999, a 50-year-old woman underwent ventriculoperitoneal (VP) shunt surgery for hydrocephalus after subarachnoid hemorrhage. She was hospitalized for fever and recurrent systemic seizures in November 2006. Head computed tomography (CT) showed only old changes. The seizures and fever were controlled by medicinal therapy. However, in December, her consciousness level suddenly decreased, and she showed progressive lower abdominal distension. Head CT showed marked ventriculomegaly, and abdominal CT showed a giant cystic mass at the shunt-tube tip in the lower abdominal cavity. Because thick pus was aspirated from the intra-abdominal mass, we diagnosed the patient with acute obstructive hydrocephalus due to an infected abdominal pseudocyst. Laparotomy and direct cyst drainage were performed, and antibiotic therapy against Streptococcus, the causative pathogen, was administered. The VP shunt tube was replaced. The postoperative course was uneventful, and postoperative CT showed hydrocephalus improvement and no pseudocyst recurrence. Abdominal pseudocysts, which are rare after VP shunt surgeries, usually occur after the subacute postoperative course in younger cerebral hemorrhagic cases. The case was quite rare because the cyst developed in the chronic phase in an older patient and was caused by streptococcal infection. The cyst components should be examined before cyst drainage when choosing surgical strategies ³⁾

A 14-year-old patient, known to have a VPS as intraventricular hemorrhage treatment, presenting cephalalgia, vomiting, apathy, and an indurate abdominal mass without fever. The first abdominal CSF pseudocyst diagnosis had been established 3 months earlier. Abdominal ultrasounds confirmed a large homogeneous cyst with the shunt tip within the pseudocyst. Cerebral CT revealed an increased ventricular size. An exploratory laparotomy with cyst aspiration, lysis of adhesions, excision of cystic walls, and repositioning of the peritoneal catheter was performed.

No antibiotics were initiated given that the cultures were negative ⁴⁾.

A case of a 4-month-old girl with shunted hydrocephalus who presented with shunt failure from a suspected abdominal pseudocyst that was found to be a fetal ovarian cyst is reported ⁵⁾.

Chick JF, Chauhan NR, Mullen KM, Kamdar NV, Khurana B. Teaching NeuroImages: massive abdominal CSFoma. Neurology. 2013 Mar 26;80(13):e146. doi: 10.1212/WNL.0b013e318289705e. PubMed PMID: 23530158 ⁶⁾.

A 22-year-old man who was admitted because of diffuse abdominal distention. A VPS was placed 21 years earlier to treat hydrocephalus secondary to spina bifida. Abdominal computed tomography (CT) revealed a homogeneous low-density fluid collection adjacent to the VPS catheter tip, causing stomach obstruction. Thus a peritoneal pseudocyst around VPS was suspected and emergency laparotomy was performed. The large mass was localized in the left upper abdomen between the stomach and mesentery of the transverse colon, exactly at the omental bursa. The cystic mass was opened and 1500 ml of clear fluid was drained; the distal end of the VPS was repositioned outside the mass. Thus, an abdominal cerebrospinal fluid pseudocyst as a complication of VPS was diagnosed ⁷⁾.

A nineteen year-old female with a VP shunt who presented with only abdominal distension suggestive of a full-term pregnancy. Abdominal CT studies subsequently established a diagnosis of APC. A total of 12.7L of fluid was drained laparoscopically, and the VP shunt was eventually revised into a ventriculo-atrial shunt. Because adult patients often present years after their VP shunt procedures with only abdominal complaints, the diagnosis of APC relies on detailed history taking and a strong clinical suspicion ⁸⁾.

A 13-year-old girl with a VP shunt presented with progressive abdominal distention, pain and vomiting. The shunt was inserted at infancy for congenital hydrocephalus. A shunt infection was treated with externalization of the shunt, antibiotics and subsequent shunt replacement. At the age of four, the shunt was revised for a distal malfunction. Nine years later, abdominal CT and ultrasound demonstrated large multiseptated cysts. The shunt was externalized and 1.8 L of sterile, xanthochromic peritoneal fluid was drained. The cerebrospinal fluid was clear, colorless, acellular and sterile with normal protein and glucose levels. Two days later, the distal portion of the shunt was replaced back into the pleural cavity. Five months later a pleural effusion formed. Thoracentesis was performed and there was no evidence of infection. The shunt was subsequently converted to a ventriculoatrial system. The patient has remained well for over 3.5 years ⁹⁾.

Pernas JC, Catala J. Case 72: Pseudocyst around ventriculoperitoneal shunt. Radiology. 2004 Jul;232(1):239-43. PubMed PMID: 15220507. ¹⁰⁾.