Benign Cystic Peritoneal Mesothelioma in a Young Woman as a Cause of Abdominal Pain: A Case Report

Benign cystic mesothelioma (BCM) is a reactive proliferation of mesothelial cells in the peritoneum resulting from peritoneal injury. Also known as cystic mesothelioma of the peritoneum, it is characterized by the formation of multiple multilocular cysts that can develop into large intra-abdominal masses. Its pathogenesis remains controversial and has been associated with factors such as abdominal surgeries, trauma, and endometriosis, being more common in women of reproductive age. In Mexico, there are no extensive population-based studies determining its prevalence. Cases are usually diagnosed incidentally and may present with symptoms such as abdominal pain and intestinal obstruction. We present the case of a 25-year-old female patient with a history of inguinal hernia repair who consulted for abdominal pain and distension. A transvaginal ultrasound revealed free fluid and a 33×23 mm cyst. Laparoscopy revealed multiple vesicular lesions on the peritoneum, and cyst removal confirmed the diagnosis of BCM. The patient had a favorable postoperative course with complete symptom resolution. BCM is an uncommon neoplasm with a high recurrence rate. Definitive diagnosis is made through histopathological analysis. Although surgical resection is the mainstay of treatment, other therapies have been explored. This case highlights the typical presentation of BCM and the good prognosis following resection. BCM is rare and primarily affects young women. A clear diagnosis requires histological investigation, and surgical resection is essential to eliminate symptoms and prevent recurrence. Long-term follow-up is necessary due to the uncertainty regarding its etiology and the possibility of recurrence.