Sporadic Mucinous Adenocarcinoma of the Colon in an Adolescent Male: A Case Report and Review of the Literature.

Colorectal cancer (CRC) is commonly seen in adult patients but makes up <1% of cancers in pediatric patients, with the largest known pediatric study having a sample size of 81 patients taken over a span of roughly 40 years. Patients typically present with nonspecific symptoms such as abdominal pain, nausea, and vomiting, which can result in the diagnosis being missed. Histopathology is typically unfavorable with signet ring colon cancer and mucinous adenocarcinoma with signet ring cell features being common. Treatment guidelines are based largely on adult protocols and include surgical resection followed by chemotherapy, with the addition of bevacizumab or cetuximab in higher-risk populations. In our case, we present a 17-year-old male with abdominal pain and weight loss who was found to have metastatic sporadic mucinous adenocarcinoma with signet ring cell features. Oncotype next-generation sequencing was found to be microsatellite stable, human epithelial growth factor receptor 2 negative, Kristen rat sarcoma viral oncogene homolog/v-raf murine sarcoma viral oncogene homolog B1/neuroblastoma reticular activating system wild type, and low tumor mutation burden with 3.7 mutations per megabase. He was treated with FOLFIRINOX at 70% dosing without bevacizumab due to recurrent admissions for small bowel obstructions and surgeries. Unfortunately, his cancer did not respond, so he proceeded with palliative chemotherapy. He expired 12 months later. This case raises the need for research on the biology of CRC in pediatric patients, as it is different from adults. It also underlines the necessity of the development of guidelines on CRC treatment in pediatric patients by initiating pediatric clinical trials or lowering the age of adult trials to under 18 years of age.