1670 Simultaneous Diagnosis of Colorectal Adenocarcinoma and Non-Hodgkin Lymphoma

• Published in: The American journal of gastroenterology Vol. 114; no. 1; p. S934
• Main Authors: Ginsberg, Terrie, Powell, Leonard, Shienbaum, Alan, Truscello, David, Shah, Maulik
• Format: Journal Article
• Language: English
• Published: 01.10.2019
• ISSN: 0002-9270; 1572-0241
• DOI: 10.14309/01.ajg.0000596212.42036.ff

INTRODUCTION: This is a case of an 84-year-old female who presented to the hospital complaining of constipation secondary to a new rectosigmoid mass. Histopathologic examination revealed an invasive adenocarcinoma of the colon along with a previously undiagnosed small lymphocytic lymphoma (SLL) in the regional lymph nodes. It is highly unusual to make a simultaneous new diagnosis of two separate malignancies found from the same specimen. We aim here to enlighten readers to the likelihood of finding this presentation in affected patients. CASE DESCRIPTION/METHODS: An 84-year-old female was admitted for a 12-day hospital stay following a 2 week history of constipation. She was found to have a new rectosigmoid mass. Abdominal CT revealed new stranding of the perirectal fat with thickening of the adjacent segment of the rectosigmoid colon. Also seen was a small tissue lesion in the adjacent fat abutting the serosal surface of the rectosigmoid colon. Colonoscopy showed a near-obstructing mass lesion located within the rectosigmoid region at approximately 18 cm from the anal verge. The obstructing lesion was encompassing approximately 90% of the colonic lumen. She underwent exploratory laparotomy with lower anterior resection with end colostomy and appendectomy. Histopathologic examination demonstrated an invasive adenocarcinoma of the rectosigmoid measuring 6.5 cm in greatest dimension. The surrounding regional lymph nodes identified in the specimen were involved by a mature B-cell lymphoma most consistent with small lymphocytic lymphoma (SLL). DISCUSSION: Detailed histopathologic examination was undertaken to establish the diagnosis, prognosis, and treatment modalities. Dual diagnoses occur uncommonly and warrant a further and more detailed investigation. Histopathologic evaluation of the regional lymph nodes within the rectosigmoid resection utilizing immunohistochemical staining, showed that the lymphocytes of the lymph nodes stained positively with CD20, CD79a, CD5 (DIM), CD23, and BCL-2. This staining pattern supports the diagnosis of a mature B-cell lymphoma most consistent with small lymphocytic lymphoma. Simultaneous diagnosis of SLL and colorectal adenocarcinoma is largely coincidental. This simultaneous development may be the result of long-term immunosuppresion secondary to the previously undiagnosed small lymphocytic lymphoma (SLL). Such a finding warrants further investigation of potential mechanisms which may lead to the development of these two separate malignancies presenting simultaneously.