Recurrent Hepatoblastoma and early-onset colorectal cancer in a child with familial adenomatous polyposis: a case report

Introduction: Familial adenomatous polyposis (FAP) is the most common hereditary polyposis syndromes in pediatric population. This hereditary cancer predisposition syndrome characterized by colonic adenomatous polyposis. Without prophylactic intervention, the risk of progression to colorectal cancer (CRC) approaches 100% by the fourth decade of life. Meanwhile, there is also risk of multiple childhood malignancies including hepatoblastoma (HB). Case presentation: We describe an 11-year-old male with a history of HB treated at ages 1 and 8, who presented with recurrent episodes of incomplete intestinal obstruction. Although postoperative adhesions or HB recurrence was considered according to imaging. Emergency laparotomy revealed an obstructing ascending colon mass and the distal bowel was carpeted with innumerable polyps. Frozen biopsy suggested adenocarcinoma, and a radical right hemicolectomy with lymphadenectomy was performed. Histology confirmed a poorly differentiated adenocarcinoma with extensive lymph node metastasis and the polyps were tubular adenomas with diffuse adenomatous polyposis. Further evaluation identified a paternal germline adenomatous polyposis coli (APC) mutation, confirming FAP. The patient is currently receiving palliative chemotherapy with 5-fluorouracil, leucovorin and oxaliplatin (FOLFOX) and bevacizumab. Conclusion: Screening for HB is warranted for children with a family history of FAP. Furthermore, the occurrence of HB in infancy should be regarded as a sentinel marker for aggressive FAP phenotypes, necessitating an intensified and individualized colorectal surveillance strategy initiated at an earlier age.