Delayed Diagnosis of Familial Adenomatous Polyposis-Related Colon Cancer in an Adolescent with Coexisting Eating Disorder: A Case Report

This case report described a 19-year-old female with a delayed diagnosis of Familial Adenomatous Polyposis (FAP)-related colon cancer, initially misattributed to an eating disorder, anorexia nervosa. Despite presenting with long-standing iron-deficiency anemia and weight loss, her symptoms were overlooked due to their overlap with common eating disorder symptoms. Upon further examination, a mass was discovered, and genetic testing confirmed FAP. The patient underwent a successful proctocolectomy, and histology revealed mucinous adenocarcinoma. The report highlighted the rarity of colorectal cancer in individuals under 20, emphasizing the importance of considering such diagnoses in young patients, particularly females, where eating disorders are prevalent. The study underscored the need for vigilance in diagnosing colorectal cancer in young patients, regardless of age, due to its potential for late-stage discovery and poor prognosis.