World Journal of Gastrointestinal Oncology

Rectal follicular thyroid-like carcinoma: A case report and review of literature

BACKGROUND Follicular thyroid carcinoma (FTC) is the second most common subtype of thyroid malignancy, with distant metastases most often to the bones, lungs, brain, and liver, and only rarely to other sites. Rectal follicular thyroid-like carcinoma is a rare condition characterized by infiltration of FTC within the rectal wall. There are almost no literature reports. CASE SUMMARY We report a case of rectal thyroid-like follicular carcinoma in a 61-year-old woman. The patient presented with intermittent rectal bleeding, and a colonoscopy revealed a mass in the mid-rectum. She underwent laparoscopic resection of the lesion, and was diagnosed with rectal thyroid-like follicular carcinoma by postoperative pathology. After a laparoscopic partial rectal resection, she was discharged on postoperative day 7. At 6 months postoperatively, the patient was still alive. CONCLUSION Rectal follicular thyroid-like carcinoma may arise from malignant struma ovarii, highlighting the need to consider ovarian origins in atypical metastases of FTC.