Bogdan Cristescu, MD, Ana Cristescu, , Tudor Cristescu, Aurora Healthcare, Green Bay, WI
Introduction: Colorectal cancers associated with ulcerative colitis (UC) are typically adenocarcinoma. By contrast, neuroendocrine carcinoma is extremely rare in patients with UC. We present a case of a patient with subtotal abdominal colectomy with ileorectal anastomosis (SAC-IRA) for UC with neuroendocrine carcinoma of the rectum 40 years after surgery.
Case Description/Methods: 82-year-old female with a long history of UC SAC-IRA 40 years ago presented with diarrhea and rectal bleeding. Colonoscopy revealed patent ileorectal anastomosis and an ulcerated distal rectal mass approximately 6 cm in size at 10 cm from the anal verge. Biopsies from the rectal mass were consistent with high-grade neuroendocrine carcinoma with 80% Ki-67 positivity and positive synaptophysin, chromogranin, INSM1 in the tumor cells. CT chest abdomen and pelvis and rectal MRI revealed a large rectal tumor extending through the muscularis into the mesorectal fat and through the peritoneum above the peritoneal reflection, involving the anal sphincter and pelvic wall musculature, abnormal lymph nodes (LN) in the right iliac chain and right iliac canal and no distant metastasis- T4N1M0, Stage IIIB. PET DOTATATE confirmed rectal malignancy and large perirectal and retroperitoneal LN with mild grade activity. Oncology recommendation was to start the patient on systemic therapy with carboplatin/etoposide and radiation therapy.
Discussion: Neuroendocrine tumors of the colon and rectum are rare accounting for 0.6% of colorectal cancers. Most colorectal carcinomas associated with UC are histologically adenocarcinoma of the sporadic type. Neuroendocrine carcinoma in patients with UC are extremely rare with a few case reports described in published literature. Continue intensive endoscopic surveillance of the rectum in patients with SAC-IRA is recommended.
Figure: Figure 1 a. Ulcerated rectal mass on colonoscopy b. CT pelvis with rectal mass c. PET DOTATATE with rectal malignancy and large perirectal and retroperitoneal lymph nodes with mild grade activity d. Rectal mass biopsy on HE stain e. Rectal mass biopsy Ki-67 stain with 80% positivity f. Rectal mass biopsy on synaptophysin stain
Disclosures:
Bogdan Cristescu indicated no relevant financial relationships.
Ana Cristescu indicated no relevant financial relationships.
Tudor Cristescu indicated no relevant financial relationships.
Bogdan Cristescu, MD, Ana Cristescu, , Tudor Cristescu, . P2709 - A Rare Case of Neuroendocrine Carcinoma in Residual Rectum After Subtotal Colectomy With Ileorectal Anastomosis for Ulcerative Colitis, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.
