Multicystic benign mesothelioma of the pelvic peritoneum presenting as acute abdominal pain in a young woman
A 28-year-old woman, gravida 2, para 0, abortion 2, had been experiencing progressive lower abdominal pain for almost 7 months. The pain worsened a week prior to her admittance and remained constant. She denied fever or chills. Her appetite, bowel and urinary function were normal and she had no recent weight loss. She experienced regular menstrual cycles and a long-standing history of dysmenorrhea and dyspareunia. Past medical history was unremarkable and there was no history of previous abdominal surgery or gynecologic disorders. Family history was not notable.\nOn physical examination, the abdomen was mildly rigid and moderately distended. She had a tender mass behind the uterus but the cervix and genital tract appeared normal. Complete blood screening profile, urinalysis and serum CA-125 assay were within normal limits. Ultrasonography and computed tomography of the pelvis revealed a 10 × 7 cm multicystic mass with irregular borders occupying the rectouterine pouch ().\nWe decided to perform laparoscopic surgery. Laparoscopic trochars were placed below the umbilicus and lower abdomen (×3, 12 mm, 5 mm, 5 mm). During the laparoscopy, we observed multiple grapelike clusters of cysts within the rectouterine pouch. The cysts appeared to originate from the peritoneum of the rectouterine pouch and attached to the uterus and left adnexa. Additional small cysts were found on the greater omentum and serosal surface of the right fallopian tube. Careful exploration of the whole abdomen, including appendix, liver and diaphragm, revealed no other abnormalities. Intraoperative frozen section histology of the multiple grapelike clusters of cysts were suspicious for serous type benign cysts. A decision was made to excise all macroscopically visible cysts. Excision of multiple clusters of cysts in the rectouterine pouch via laparotomy, resection of the peritoneum of the rectouterine pouch, partial greater omentectomy and electro-fulguration (argon plasma coagulator) of small cysts on the serosal surface of the right fallopian tube was performed.\nGrossly, multiple cysts were present measuring up to 2 cm. Microscopically, the cysts were lined by flattened or cuboidal cells. The lining cells were reactive immunohistochemically for Pan-CK, calretinin, D2-40 and CK5/6 but negative for CD34 (). Histological examination of the excised specimens were consistent with a MBM of the pelvic peritoneum. The postoperative course was uneventful. The patient is well at 3-month follow-up with no clinical evidence of disease recurrence.