Resident Physician Nassau University Medical Center East Meadow, NY
Kevin J. Yeroushalmi, MD, Bobby Jacob, MD, Kaleem Rizvon, MD, FACG; Nassau University Medical Center, East Meadow, NY
Introduction: Neuroendocrine Tumors (NETs) are of neural crest origin arising from the enterochromaffin cells. Rectal NETs are the second most common NET. The incidence of rectal NETs has risen more than tenfold over the past forty years likely due to the improvement in colorectal cancer prevention screening. The optimal management for treating low-grade rectal NETs remains controversial with multiple curative approaches available, including endoscopic submucosal dissection, endoscopic mucosal resection, and transanal excision. We present a case of a middle-aged Hispanic female with grade 1 NET that was cured with transanal endoscopic microsurgery.
Methods: A 60-year-old Hispanic female was referred to gastroenterology clinic for colorectal cancer screening after having a positive fecal occult blood test result. Review of systems was negative for constipation, change in stool caliber, weight loss, or hematochezia. A colonoscopy was subsequently performed revealing a 4mm submucosal lesion in the rectum. Immunohistochemical staining revealed that the lesion was positive for pan-cytokeratin (AE1/AE3) and synaptophysin [See Figure 1]. The proliferative index was less than 2%. The patient was subsequently referred to colorectal surgery for transanal excision of the lesion and pathology revealed a well differentiated neuroendocrine tumor, grade 1, 0.35cm in size, with invasion into the submucosa [See Figure 2]. Multiphase CT Abdomen/Pelvis as well as CT thorax for staging purposes were both unremarkable. Endorectal ultrasound and pelvic MRI that was performed six months and one year postoperatively, respectively, showed no evidence of residual tumor. Octreotide scan that was performed approximately 18 months postoperatively was similarly unremarkable. Lastly, the patient underwent video capsule endoscopy to rule-out any small bowel carcinoid tumor and this test was unremarkable as well. Discussion: The optimal therapeutic approach for rectal NET remains controversial but usually depends on the grade and stage of the tumor as well as the expertise of the facility. Our patient was treated successfully with transanal excision and she remains asymptomatic nearly four years post-operatively. There are currently no established guidelines as to the appropriate surveillance interval for repeat colonoscopy. A risk-benefit analysis to develop appropriate surveillance guidelines is essential to avoid aggressive surveillance in low risk patients.
Figure 1. Cytoplasmic staining demonstrating positivity for synaptophysin.
Figure 2. Nodule composed of neuroendocrine neoplastic cells.
Disclosures: Kevin Yeroushalmi indicated no relevant financial relationships. Bobby Jacob indicated no relevant financial relationships. Kaleem Rizvon indicated no relevant financial relationships.