Carcinoid Tumours: This is a rare benign monodermal teratoma. One third of patients present with the carcinoid syndrome (flushing, diarrhoea, cardiac murmurs and peripheral edema). The syndrome occurs in the absence of metastases because ovarian venous drainage by-passes the liver (where hormones produced by carcinoids are metabolized). Microscopically, the carcinoid tumour is typically of insular (mid gut) type. Carcinoids in the ovary may also be metastatic from the intestinal tract.