Synchronous Duodenal Carcinoid and Adenocarcinoma of the Colon

Carcinoid tumors are a histological subtype of well differentiated, low to intermediate grade, slow-growing neuroendocrine malignancies capable of secreting bioactive peptides, such as 5-hydroxytryptamine (5-HT, serotonin), chromogranin-A and chromogranin-C. Here we present a case of a duodenal carcinoid that simultaneously occurred with adenocarcinoma of the colon. A 59-year-old male with a past medical history of hepatitis C and hypertension presented complaining of worsening abdominal pain associated with 2 - 3 episodes per week of bright red blood per rectum for the past month. He also reported a 20 pounds weight loss in the last 6 months. Social history was significant for a 15 pack year history. Vitals on admission were within normal limits. Physical exam was significant for right upper quadrant tenderness without guarding, rebound, or organomegaly. Rectal exam revealed no blood or masses. Laboratory results showed iron deficiency anemia with hemoglobin of 9.6 K/mm³. Esophagogastroduodenoscopy revealed a 4 mm duodenal polyp. Colonoscopy was terminated early secondary to a large circumferential obstructing mass found in the descending colon. Immunohistochemistry of the duodenal biopsy was positive for synaptophysin and chromogranin-A; consistent with the diagnosis of stage I carcinoid tumor. Biopsy results of the colonic mass showed a stage I well-differentiated adenocarcinoma. The patient underwent a left colectomy and partial duodenectomy; he remains in remission after 2 year of close follow up. When the diagnosis of small bowel carcinoid is made, further screening for other primary neoplasms should be sought to prevent potential late stage diagnosis of synchronous malignancies. This is crucial because patients' demise usually result from the associate tumor and not the carcinoid component. Finally, we would like to raise clinician's awareness regarding the incidence of this entity since some of the studies suggest that it is more common than it was previously thought.