Synchronous Adenocarcinoma of the Colon and Rectal Carcinoid

Abstract

Primary colonic adenocarcinoma and synchronous rectal carcinoids are rare tumors. Whenever a synchronous tumor with a nonmetastatic carcinoid component is encountered, its prognosis is determined by the associate malignancy. The discovery of an asymptomatic gastrointestinal carcinoid during the operative treatment of another malignancy will usually only require resection without additional treatment and will have little effect on the prognosis of the individual. This article reports a synchronous rectal carcinoid in a patient with hepatic flexure adenocarcinoma. We present a case of a 46-year-old Hispanic woman with a history of hypothyroidism, uterine fibroids and hypercholesterolemia presenting with a 2-week history of intermittent abdominal pain, mainly in the right upper quadrant. She had no family history of cancers. Physical examination was significant for pallor. Laboratory findings showed microcytic anemia with a hemoglobin of 6.6 g/dl. CT abdomen showed circumferential wall thickening in the ascending colon near the hepatic flexure and pulmonary nodules. Colonoscopy showed hepatic flexure mass and rectal nodule which were biopsied. Pathology showed a moderately differentiated invasive adenocarcinoma of the colon (hepatic flexure mass) and a low-grade neuroendocrine neoplasm (carcinoid of rectum). The patient underwent laparoscopic right hemicolectomy and chemotherapy. In patients diagnosed with adenocarcinoma of the colon and rectum, carcinoids could be missed due to their submucosal location, multicentricity and indolent growth pattern. Studies suggest a closer surveillance of the GI tract for noncarcinoid synchronous malignancy when a carcinoid tumor is detected and vice versa.

A rare case of metachronous neuroendocrine tumor after a colorectal adenocarcinoma: qualitative critical review of synchronous and metachronous gastrointestinal NET

“…To date, the literature in English reveals, 20 case reports (18 synchronous cases [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24], 2 metachronous cases [25,26]), 2 case series [25,27], 3 review articles [28][29][30], and about 10 retrospective studies [31][32][33][34] or population-based studies from a National Registry [35][36][37][38][39][40][41] of synchronous or metachronous NET with a second primary malignancy (SPM). A total of 31 patients in 24 articles were included in the study: 28 patients with a synchronous gastrointestinal NET and colorectal adenocarcinoma (Table 1) and 3 patients (including the present study) of 3 articles with metachronous gastrointestinal NET and colorectal adenocarcinoma ( Table 2).…”

“…Pearson and Fitzgerald were the first to report the high incidence (23%) of second primary malignancies (SPM) in patients with small intestinal NETs at autopsy [27]. A certain number of NETs were incidentally found during surgery for other [7] 1972 53 M Rectum Rectum -Lotlikar et al [25] 1981 53 M Rectum Small bowel -Lotlikar et al [25] 1981 67 F Right colon Small bowel -Lotlikar et al [25] 1981 60 F Sigmoid colon Small bowel -Sacchi et al [8] 1988 57 M Right colon Small bowel -Tse et al [9] 1997 72 M Hepatic flexure Small bowel -Habal et al [28] 2000 52 M Sigmoid colon Rectum Cioffi et al [10] 2005 64 F Ileum Small bowel -Klucinski et al [11] 2006 72 F Transverse colon Small bowel -Chemli et al [12] 2007 63 F Right colon Small bowel -Aslam et al [13] 2009 67 F Sigmoid colon Small bowel G1 Boland et al [14] 2009 77 F Left colon Meckel's diverticulum -McHugh et al [15] 2009 74 F Rectum Small bowel -Wohadlo et al [29] 2011 53 M Splenic-hepatic flexure Small bowel -Gurzu et al [16] 2012 78 F Sigmoid colon Small bowel G3 Pozzato et al [17] 2012 61 M Right colon Duodenum G1 Katalinic 2014 et al [18] 2014 63 M Right colon Meckel's diverticulum G1 Zhu et al [19] 2015 64 F Rectum Rectum G1 Almajano et al [20] 2016 66 M Right colon Small bowel G1 Mohapatra et al [21] 2016 83 M Sigmoid colon Left colon G3 Nejatollahi et al [22] 2016 83 M Sigmoid colon Small bowel G1 Vootla et al [23] 2016 46 F Hepatic flexure Rectum G1 Winn et al [30] 2017 40 M Sigmoid colon Rectum G1 Winn et al [30] 2017 70 M Sigmoid colon Rectum G1 Napolitano et al [24] 2017 72 M Right colon Small bowel G1-G2 cancers. The estimated rate of SPM associated with other malignancies was 2.3% in surgical cases and 8.1% in autopsy cases [42].…”