An unusual presentation of solitary ovarian metastasis from colorectal cancer in an elderly woman: a case report

Background: There have been cases of colorectal cancer (CRC) metastasizing into the ovary. This study reports a case involving solitary ovarian metastasis (OM) from CRC, which is very rare in the absence of other pelvic and peritoneal metastases. This atypical clinical presentation added to the complexity of the diagnosis. Case Description: We report a case of solitary OM-CRC in a 48-year-old woman. The patient underwent CRC surgery and refused follow-up after three rounds of chemotherapy. Approximately 14 months later, the patient presented with vaginal bleeding for 2 months. The magnetic resonance imaging (MRI) showed a huge solid cystic mass in the right adnexa. Intraoperatively, the right ovary was found to be enlarged and smooth without adhesions. By careful examination of the abdominal cavity, no metastatic lesions were found in the left ovary and uterus, and no seedings were found in the rest of the pelvis and abdomen. After removal of the uterus and bilateral adnexa, the histologic examination revealed metastatic adenocarcinoma of the right ovary with a considered rectal carcinoma of origin. Positive staining for multiple tumor-associated markers, which further established the primary nature of CRC. These findings support a possible diagnosis of primary CRC and ovarian metastases. The patient recovered well after the operation and no recurrence or metastasis was seen 18 months after the operation. Conclusions: Solitary ovarian metastases from CRC can be better managed and treated by increasing clinicians' vigilance for this rare condition. This helps to improve the patient's prognosis and quality of life.