The antiestrogen tamoxifen in the treatment of recurrent benign cystic mesothelioma.

Benign cystic mesothelioma is a tumor characteristically found in women during the reproductive years. These tumors are infrequently found after castration or menopause, suggesting some degree of hormonal sensitivity. Such aspects of the tumor suggest a potential role for antiestrogens as medical management and an alternative to radical surgery. We treated a 19-year-old woman with a symptomatic pelvic mass secondary to a recurrent benign cystic mesothelioma 2 years after radical surgery with the antiestrogen tamoxifen. An initial reduction in volume and arrest of growth was followed by stabilization in size and disappearance of symptoms. Therapy was continued for 18 months with no change in the volume of the cystic structure. The patient continued to be asymptomatic. Periodic surveillance with quantitative digital radiography for bone density showed no change in bone mineral density. Serum testing for liver function studies was normal throughout treatment. This case suggests that antiestrogens may have a role in the medical management of these rare estrogen-dependent neoplasms. The initial reduction in size and arrest in growth further suggest extreme sensitivity of this tumor to manipulation of the hormonal milieu. Therapy with the antiestrogen tamoxifen in this setting may provide an option for long-term medical management in cases of symptomatic recurrent cystic mesotheliomas.