Primary neuroendocrine tumor in the presacral region: A case report

Figure 1 Magnetic resonance imaging scans. A: Sagittal view demonstrating a 57 mm × 29 mm presacral mass, with margin and separation being visible; B: T2STIR-weighted axial MRI image showing high intensity of the tumor.

Figure 2 Transanal endoscopic ultrasound revealing a non-homogeneous echo-poor area 6 cm away from the sacral coccyx and in the direction of the sacrum and hyperechoic periosteum with clear membrane. No abundant internal blood flow was observed.

Figure 3 Final pathological images of the tumor. A: The mass removed by resection; B: The tumor component tested positive for the marker Syn (×100); C: The tumor stained using H&E (×100); D: The tumor stained using H&E (×200); E: The tumor component was diffusely positive for the marker CD56 (×100); F: The tumor component was positive for CK (×100); G: The tumor’s Ki67 index was 30% (×100).

Figure 4 Two months after the resection, only the small fistula was not healed.