Abdominal Cyst in a 39-year-old Woman

A 39-year-old premenopausal woman presented with complaints of persistent pain in her lower abdomen lasting one year. She had history of exploratory laparotomy two years prior for tubercular pyoperitoneum. She completed her course of antitubercular medication and remained asymptomatic in the intervening period (around 10 months). She then developed pain, abdominal distension, and constipation. An abdominal examination revealed a midline scar. Her abdomen was soft and non-tender. It appeared distended below the umbilicus, more in the left iliac fossa than the right. An ill-defined abdominopelvic mass was palpable in the lower abdomen. Rectovaginal examination also suggested fullness in the rectouterine pouch. Ultrasonography (USG) of the abdomen demonstrated a large anechoic abdominopelvic cystic mass extending from the left lower quadrant of the abdomen deep in the pelvis into the rectouterine pouch. The left ovary appeared normal but adhered to the uterus posteriorly. The right ovary was visualized separately and was normal. Contrast-enhanced computed tomography (CECT) scan, which was performed for further characterization of the cystic mass and its relation to adjacent anatomic structures. CECT revealed displacement of bowel loops by a well-defined irregularly loculated fluid collection measuring 23 × 12 × 20 cm in the left paracolic gutter and the pelvis [Figure 1]. Both the ovaries appeared normal on CECT and transvaginal USG. Serum CA-125 was 9.2 U/mL. USG guided aspiration of the cystic mass yielded clear fluid. The fluid protein was 4.8 g%, sugar 92 mg% and fluid was negative for acid-fast bacilli on Ziehl–Neelsen staining. Adenosine deaminase activity level in the fluid was 14.0 U/L. Fluid cytology revealed a few reactive mesothelial cells