A 21-year-old Japanese male presented at the outpatient department with sporadic nausea, abdominal discomfort, and worsening headache. Cysto-peritoneal (CP) and VP shunts were implanted 11 months after birth by another doctor for the treatment of hydrocephalus due to a suprasellar arachnoid cyst. His VP shunt had been replaced twice by the age of 13 years. At the time of last surgery, the CP cranial tube was removed while the extra-cranial tube was left in place because it passed through the mediastinal space rather than the subcutaneous tissue and adhered to the surrounding organs. During this course of treatment, the patient had been diagnosed with slit ventricle syndrome but had no current restrictions on daily activity except for mild mental retardation. He had no remarkable medical history to suggest systemic abnormalities or risk factors for infection and had not traveled to foreign countries.
Nausea was reported for 2 months and abdominal pain for 1 month before admission. A few days before presentation, the patient developed fever and mild consciousness disturbance. Initial physical examination revealed a fever of 38.9 C, restlessness, and significant abdominal distension but no meningeal irritation or focal signs of neurological dysfunction. White blood cell count was 10,900/mm3, and serum C-reactive protein level was 31.8 mg/dl. Chest X-ray was negative but brain and abdominal computed tomography (CT) scans revealed enlarge lateral ventricles, a huge peritoneal cyst surrounding the distal end of the peritoneal tube, and fluid in the sheath surrounding the peritoneal tube, indicating possible shunt blockage and a concomitant increase in intracranial pressure (ICP) [Figure 1]. In contrast, chest CT revealed no abnormalities in bilateral lung fields or subcutaneous tissues of the chest. The tentative diagnosis was shunt malfunction resulting from some undefined peritoneal abnormality.
Continuous external drainage was established to remove CSF from the lateral ventricles and peritoneal cyst. The CSF was clear and the fluid in the abdominal cyst was xanthochromatic. Chemical screening of CSF was negative. The cyst fluid contained 1495 cells/mm3 (69 monocytes and 1426 polycytes/mm3) and 1.4 g/dl total protein. Antibiotic therapies for abdominal infection were empirically administered and bacterial cultures analyzed, but no causative pathogen was identified.
Preoperative clinical symptoms immediately improved after surgery to insert an external drainage system. However, the cyst fluid gradually recollected and signs of mild inflammation remained despite antibiotic therapy. In the second stage of treatment, transcutaneous drainage of the cyst under CT guidance was performed; however, again cyst fluid recollected [Figure 2]. In the third stage of treatment, laparotomy was performed, which revealed no membrane surrounding the abdominal cyst (defining it as a pseudocyst), no malignancies within the omentum, and no ascites within the abdominal cavity.
Throughout the course of treatment, all cytological examinations for malignancies were negative and bacterial cultures did not reveal a causative pathogen. Two months after initial surgery, inflammation of his left knee joint became apparent. The fluid taken from the joint was xanthochromatic, similar to the pseudocyst fluid, and Mycobacterium tuberculosis was detected in a culture from the fluid. Thus, the patient was diagnosed with an abdominal pseudocyst associated with TBP and successfully treated by anti-TB agents following insertion of a ventriculo-pleural shunt [Figure 3]. At follow-up 2 years after treatment, he again presented with signs of inflammation, and the abscess around the CP shunt was strongly suspected as the cause. He was again treated with anti-TB agents, and all signs of inflammation subsided after the removal of the previous CP shunt tube by thoracoscopic surgery.
CT after insertion of the ventriculo-pleural shunt. Chest CT showing the distal part of the shunt (arrow), a small amount of cerebrospinal fluid in the thorax and the distal tube of the previous CP shunt (arrowhead) (c).