Colonic adenocarcinoma in a pediatric patient: A case report and review of literature

Abstract

BACKGROUND

Colorectal cancer (CRC) is rare in children, though incidence appears to be rising. Some cases are associated with hereditary syndromes and microsatellite instability, both of which involve defects in mismatch repair genes. Diagnosis is frequently delayed due to non-specific symptoms and low clinical suspicion, resulting in advanced-stage disease. Pediatric CRC is often aggressive, with poor outcomes and no routine screening. While the gut microbiota is implicated in adult CRC, its role in pediatric cases remains unclear, warranting further investigation.

CASE SUMMARY

This single-patient case with a matched healthy control for microbiota comparison describes a 14-year-old boy who presented with non-specific symptoms. Examination revealed abdominal tenderness, microcytic anemia, leukocytosis, and elevated inflammatory markers. Imaging showed thickening of the ascending colon, and biopsy confirmed poorly differentiated adenocarcinoma (stage pT3N2b) with lymphovascular invasion, and 13 of 61 lymph nodes were positive for metastasis. He underwent right hemicolectomy. A year later, surveillance colonoscopy revealed a rectal tubular adenoma. Then, he developed anastomosis site recurrence and peritoneal metastasis and underwent cytoreductive surgery with hyperthermic intraperitoneal chemotherapy with mitomycin. Later, a chest computed tomography scan showed pulmonary nodules, and the patient was treated with additional chemotherapy. In February 2025, a further peritoneal recurrence led to right hydroureteronephrosis. Surgery was delayed at the patient’s request. In June 2025, he presented with bowel obstruction and underwent exploratory laparotomy, venting gastrostomy, and end ileostomy. His code status was subsequently changed to comfort care.

CONCLUSION

Pediatric CRC is aggressive and rare. Integrated genomic and microbiota analyses may enhance understanding and guide future diagnostic strategies.

Keywords: Pediatric; Gut microbiota; Genomics; Early onset colorectal cancer; Case report

Core Tip: This case reports a rare diagnosis of colon cancer in a 14-year-old patient, emphasizing the challenges of delayed diagnosis in pediatric patients due to non-specific symptoms and low clinical suspicion. The report uniquely integrates genomic testing and gut microbiota profiling, revealing potential molecular and microbial contributions to pediatric colorectal cancer pathogenesis. These findings underscore the importance of comprehensive evaluation in early-onset cases and suggest a novel direction for research into the role of the gut microbiota in pediatric malignancies, with implications for diagnosis, prognosis, and management strategies.