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

Figure 1 Colonoscopy findings. Colonoscopy revealed a 2.0 cm × 3.0 cm elevated lesion with surface ulceration located 10 cm from the anal verge.

Figure 2 Imaging examination findings. A: Pelvic magnetic resonance imaging showed focal thickening of the upper rectal wall with a nodular mass protruding into the lumen; B: Contrast-enhanced abdominal computed tomography confirmed localized rectal wall thickening with mild enhancement.

Figure 3 Pathological examination findings. A: Pathological examination revealed infiltration of thyroid tissue within the mucosa and muscularis propria of the rectal wall, with features of malignancy, consistent with metastatic follicular thyroid carcinoma; B: Fine-needle aspiration cytology of the right thyroid lobe indicated a Bethesda II benign nodule.