Leiomyomatosis peritonealis disseminata and ovarian Brenner tumor associated with tamoxifen use

Tamoxifen is frequently administered as adjuvant therapy for breast carcino ma and produces weak estrogen agonist effects in estrogen sensitive tissues . In addition to producing a measurable increase in the risk of endometrial carcinoma, tamoxifen has also been associated with increasing size of uter ine leiomyomata as well as the development of new leiomyomata. As the indic ations for tamoxifen therapy expand, surveillance for additional potential associated adverse outcomes is warranted. A 44-year-old woman with a history of bilateral breast carcinoma presented with leiomyomatosis peritonealis disseminata and a right ovarian Brenner tu mor 18 months after beginning adjuvant tamoxifen therapy. Although a causal link cannot be proven, this case is the second reported association betwee n leiomyomatosis peritonealis disseminata, an ovarian Brenner tumor, and ta moxifen use for the treatment of breast carcinoma. Given the hormonal sensi tivity of leiomyomatosis peritonealis disseminata, both mutagenic and mitog enic effects of tamoxifen on this rare entity must be considered. In the se tting of continued hormonal treatment for breast carcinoma, the management of leiomyomatosis peritonealis disseminata presents unique clinical challen ges.