Submitted, Not Presented: Clinical Vignettes/Case Reports - Colorectal Cancer Prevention.

Abstract

Our patient is a 47-year-old male with no significant medical history who presented with progressively worsening dyspnea, decreased exercise tolerance, and bilateral lower extremity edema for the last 5 weeks. He reported diarrhea but denied any dark stools, and had a 60-pound intentional weight loss over the previous four months. He recently returned from a 4-week cruise from Florida to Denmark and his symptoms began while aboard the ship. On exam, he was afebrile with stable vital signs. He was morbidly obese with a BMI of 61 and appeared pale. A grade III/VI systolic murmur was noted at the second intercostal space and he had bibasilar crackles and 2+ bilateral lower extremity pitting edema. Initial stool guaiac testing was negative. He was found to have a profound anemia with a hemoglobin of 3.6 g/dL and a hematocrit of 13.5%. His ferritin and iron levels were also significantly decreased. His symptoms improved blood transfusions and intravenous Lasix, however, his hemoglobin continued to decrease slowly over the next several days requiring additional blood transfusions. His echocardiogram revealed no abnormalities and a repeat stool guaiac test was positive. A colonoscopy was performed revealing a large mass in the ascending colon, and histological analysis was consistent with invasive colonic adenocarcinoma. Further imaging showed metastases to the peritoneum and he was classified as having Stage IVB colon adenocarcinoma. Discussion: In the United States colorectal cancer is the third most commonly diagnosed cancer and is the second leading cause of cancer-related deaths. A common presentation of colonic adenocarcinoma is iron deficiency anemia, especially when located in the ascending colon. However, it is uncommon to remain asymptomatic from severe anemia until developing signs of heart failure. His heart failure symptoms resolved after adequate resuscitation with blood products, however he continued to require transfusions due to continual slow blood loss from the tumor. Unfortunately, he did not have any family history of gastrointestinal disorders or cancers and his first screening colonoscopy was not due for another three years. Obesity itself increases the frequency of colon cancer, and this appears to be our patient's sole identifiable risk factor. Our case illustrates the importance of recognizing early symptoms of iron deficiency anemia and correlating this with its most common cause, which is occult gastrointestinal blood loss.