The new england journal of medicine n engl j med 383;1 nejm.org July 2, 2020 68 Clinical Problem-Solving From the Department of Medicine (C.D.O., C.R.O., J.J.), Section of Hematol- ogy (A.I.L.), and the Department of Pa- thology, Section of Digestive Diseases (D.J.), Yale School of Medicine, New Haven, CT. Address reprint requests to Dr. Odio at camila.odio@nih.gov. N Engl J Med 2020;383:68-74. DOI: 10.1056/NEJMcps1817531 Copyright © 2020 Massachusetts Medical Society. A 57-year-old man with a history of rectal adenocarcinoma for which he had under- gone colostomy presented to the emergency department with an unintentional 22.6-kg weight loss and malaise, occurring over a period of 6 months. During this time, his body-mass index (the weight in kilograms divided by the square of the height in meters) dropped from 23.9 to 16.6. Progressive weakness developed, limiting his ability to complete activities of daily living. He noted abdominal distention and leg pain. He reported no nausea, vomiting, anorexia, joint pains, fevers, or cough. He noted soft, brown, formed colostomy output without associated blood, mucus, or oiliness. Unintentional weight loss in a middle-aged man arouses concern about a possible cancer. It is critical to review this patient’s rectal-cancer treatment and surveil- lance. The differential diagnosis also should include prostate cancer and lung cancer, which are common in this age group. Alternatively, failure to thrive could result from heart failure, cirrhosis, adrenal insufficiency, diabetes mellitus, or malnutrition. Infections such as human immunodeficiency virus (HIV) infection and tuberculosis can be manifested insidiously. A detailed social history should be obtained. Furthermore, malabsorption syndromes such as celiac and inflamma- tory bowel disease are associated with altered bowel habits that may be obscured in a patient with a colostomy. Six years earlier, the patient received a diagnosis of stage IIIB (tumor–node–metas- tasis classification, T3N1aM0) rectal adenocarcinoma after undergoing a colonos- copy for hematochezia. His treatment consisted of neoadjuvant chemotherapy, external-beam radiation therapy, and an abdominoperineal resection, resulting in a colostomy. Regular surveillance colonoscopies (most recently, 3 years before the cur- rent presentation), computed tomographic (CT) imaging (9 months earlier), and carcinoembryonic antigen (CEA) measurements (6 months earlier) were negative for recurrence. The patient was a lifetime nonsmoker and reported no alcohol or recre- ational drug use. He did not have a history of homelessness, imprisonment, or known tuberculosis exposure. He reported no changes in eating habits and followed a well-balanced diet. The patient lived alone, worked as a mechanic, and had had no sexual contact in more than 2 years. The family history included stomach cancer in his mother. He was born in Puerto Rico and was of European ancestry; he moved permanently to Con- necticut at the age of 19 years and last visited Puerto Rico 8 months before the current Caren G. Solomon, M.D., M.P.H., Editor Cryptic Cachexia Camila D. Odio, M.D., Corey R. O’Brien, M.D., Jeremy Jacox, M.D., Ph.D., Dhanpat Jain, M.D., and Alfred I. Lee, M.D., Ph.D. In this Journal feature, information about a real patient is presented in stages (boldface type) to an expert clinician, who responds to the information by sharing relevant background and reasoning with the reader (regular type). The authors’ commentary follows. The New England Journal of Medicine Downloaded from nejm.org at UNIVERSITY OF EXETER on July 1, 2020. For personal use only. No other uses without permission. Copyright © 2020 Massachusetts Medical Society. All rights reserved.