Rare large sigmoid hamartomatous polyp in an elderly patient with atypical Peutz-Jeghers syndrome: A case report

Figure 1 Melanin pigmentation of skin and mucosa of this patient. A: The patient had a spot of melanin pigmentation in the buccal mucosa on the right side; B: The left buccal mucosa of the patient was normal without pigmentation; C: The patient's lower lip was marked with melanin pigmentation, but the color was light; D-F: Pigmentation of the patient's hands; G: Pigmentation of the patient's perineum. White circles outline areas of pigmentation.

Figure 2 Contrast-enhanced computed tomography of bilateral adrenal glands. A: Imaging of the right adrenal gland; B: Imaging of the left adrenal gland.

Figure 3 Contrast-enhanced computed tomography of the abdomen. A: The sigmoid colon mass was observed in the horizontal plane; B: The sigmoid colon mass was observed in the sagittal planes; C: The sigmoid colon mass was observed in the coronal planes; D: 3D reconstruction model of sigmoid colon mass. The orange arrow points to the sigmoid mass.

Figure 4 Colonoscopy and endoscopic forceps were used to obtain tissue pathological biopsy. A: The appendiceal fossa mucosa was smooth without dysplasia or polyps; B: The ileocecal mucosa was smooth and no ulcer or neoplasm was observed; C-E: A grape-like mass was seen in the sigmoid colon 30 cm to 35 cm from the anal verge; F: No abnormal lesions were found in the rectum; G: Pathological changes of hamartomatous polyps; H: Pathological examination showed mucosal prolapsed changes and ulcer formation in some areas.

Figure 5 Postoperative tissue sample and pathological results. A-D: The resected grape-like mass of sigmoid colon was showed and the polyp size was approximately 6 cm × 5 cm × 5 cm; E: Hematoxylin-eosin staining of the lesions. There were dendritic-like structures formed by the proliferation of muscle fibers in the muscularis mucosa, which were overlaid with intrinsic mucosa tissue and piled up into villous structures.