Malignant Peritoneal Mesothelioma with Possible Hormone Association and Multiple Endocrine Neoplasia in a Young Female with an Indolent Clinical Course

Malignant peritoneal mesotheliomas are rare, aggressive tumors that carry an overall 5% 5-year survival rate. This case highlights a young woman with an incidentally discovered malignant peritoneal mesothelioma which grew during pregnancy and has had an indolent course despite the inherent aggressive nature and pathologic appearance of this cancer. Immunohistochemical staining did not show hormone receptors however clinically it is believed she had hormone associated disease. Follow up over the last five years has demonstrated waxing and waning abdominal CT findings that resolve with menses and have not been amenable to biopsy and the patient has remained well. Although prognosis is considered poor for malignant peritoneal mesothelioma, factors such as gender and hormone association may lead to a more indolent course. This patient has also been diagnosed with multiple endocrine neoplasia (MEN1) after being found to have primary hyperparathyroidism and an islet cell tumor. This is only the second reported case of MEN1 and malignant peritoneal mesothelioma.