[Unexpected diagnosis of a cystic pelvic mass: benign mesothelioma of the uterus: case report].

BACKGROUND Benign mesothelioma is a rare tumour mostly found in the genital tract. CASE We report the case of 30-years old woman presenting pelvic pain. The ultrasound scan revealed a cystic pelvic mass. Laparoscopic exploration showed a uterine posterior formation. The resection of the dome was performed. Histologic exam and immnunochemistry concluded to a benign cystic mesothelioma. CONCLUSION The benign mesothelioma of the uterus is usually discovered in histology, differential diagnosis for solid forms can be made with leiomyoma or adenomyoma, whereas the cystic forms can be discussed essentially with the ovarian cysts. The presence of mesothelial immunophenotype in immunochemistry improves diagnosis. Clinical outcome is always favourable without recurrence or malignant transformation.