Simultaneous rectal neuroendocrine tumors and pituitary adenoma: A case report and review of literature

Figure 1 Images. A and B: ¹⁸F-ALF-NOTATATE positron emission tomography-computed tomography (PET/CT) images and corresponding ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/CT images in a patient with rectal neuroendocrine tumors in our hospital; C and D: ⁶⁸Ga-DOTANOC PET/CT and ¹⁸F-FDG PET/CT images in the First Affiliated Hospital of Sun Yat-sen University.

Figure 2 Two lesions. A: The one lesion at the lower rectum under colonoscopy; B: The second lesion at the lower rectum under colonoscopy.

Figure 3 Hematoxylin-eosin staining and immunohistochemical staining. A and B: Hematoxylin-eosin staining shows the pathological features of rectal neuroendocrine tumors in the larger and smaller tumor tissue specimens (20 ×); C-E: Immunohistochemical staining of neuroendocrine markers CD56, Syn, and CgA in representative tumor tissue selected by the physician (4 ×); F: Ki-67 expression in the neuroendocrine tumor at the rectum by immunohistochemistry (10 ×). Brown nuclear stain highlights Ki-67-positive tumor cells.

Figure 4 Tumor metastasis was observed in the peri-intestinal lymph nodes (4/15). A and B: Laparoscopic low anterior resection with total mesorectal excision was performed 5 mo after diagnosis of the rectal lesions. Central lymph nodes were selected from the lesion for hematoxylin–eosin staining to evaluate the metastasis of neuroendocrine cells (A: 100 ×, B: 400 ×); C-E: Immunohistochemical detection to evaluate the expression and distribution of neuroendocrine markers SSTR2, syn, and CgA in central lymph nodes (400 ×); F: Ki-67 expression in central lymph nodes by immunohistochemistry (400 ×).

Figure 5 Magnetic resonance imaging for pituitary adenoma. A: Pretreatment with long-acting octreotide (20 mg); B: Pretreatment with long-acting octreotide (20 mg) for 28 d.