Colonic adenocarcinoma as a secondary malignancy after treatment of embryonal rhabdomyosarcoma

Survivors of childhood malignancies are known to be at an increased risk for developing a variety of secondary cancers. Primary adenocarcinoma of the colon is very rare in children and adenocarcinoma of the colon occurring as a secondary malignancy in children is much rarer.

A boy with a history of successfully treated embryonal rhabdomyosarcoma developed adenocarcinoma of the colon as a secondary cancer.

The boy presented with a solid mass of the left cheek at 3 years of age. The mass was excised and histological examination showed embryonal rhabdomyosarcoma. He was treated with multi-agent chemotherapy and local radiotherapy, which resulted in complete remission. Four years later, he presented with recurrent colicky abdominal pain and bleeding per rectum and was found to have intussusceptions. Colonoscopy revealed a tumor in the transverse colon, which was biopsied and proved to be an adenocarcinoma. The boy underwent excision followed by chemotherapy using an adult colon cancer regimen. He is currently off chemotherapy for 2 years with no evidence of the disease.

We report a rare case of colon cancer after treatment of rhabdomyosarcoma. Colorectal adenocarcinoma must be kept in mind as a secondary neoplasm following treatment for early childhood malignancies although it is extremely rare.