Benign Cystic Peritoneal Mesothelioma: What Is It?

The well defined but rare entity of benign cystic mesothelioma is reported. The aetiology of this neoplasm remains obscure. The presenting features make a precise preoperative diagnosis difficult; information provided by computed tomography and cytology may help. A firm diagnosis can only come from electron microscopic or immunohistochemical examination of the tumour. Diagnostic accuracy and diligent follow up are essential because, although the tumour is considered benign, it does tend towards local recurrence.

Benign cystic mesothelioma (BCM) is an uncommon lesion of the peritoneum occurring predominantly in women of reproductive age. Although most patients are managed by surgical resection, a reported high incidence of cyst recurrence has led to the use of hormonal therapy in isolated cases in an attempt to control cyst size and relieve local symptoms. To date, the estrogen receptor (ER) and progesterone receptor (PR) status of BCM has not been evaluated.

Benign cystic mesothelioma is a neoplasm composed of mutiple small flluid-filled cysts. In terms of malignant potential it lies between two other neoplasms of mesthelial origin: adenomatoid tumour and malignant peritoneal mesothelioma. The most common peritoneal adenomatoid tumour is usually an incidental finding at laparotomy and rarely causes symtoms. In contrast, the malignant mesothelioma, which is known to develop after exposure to asbestos, frequently metastasises and is fatal.