Neuroendocrine Cancer of Rectum Metastasizing to Ovary.

Neuroendocrine carcinomas (NECs) are rare malignancies that originate from the hormone-producing cells of the body's neuroendocrine system. Rectal high grade NEC (HG-NEC) constituting less than 1% of colorectal cancers can cause large ovarian metastasis that may be the initial presenting complaint. Ovarian Krukenberg tumor from a primary rectal HG-NEC is a very unusual and exceedingly uncommon differential diagnosis for secondary ovarian malignancy.