Rapid growth of a retroperitoneal rhabdomyosarcoma following right hemicolectomy for ascending colon cancer: report of a case.

We report herein the case of a 69-year-old man in whom rapid growth of a retroperitoneal rhabdomyosarcoma occurred following hemicolectomy for ascending colon cancer. On his first admission for surgery, a small lesion, 1.5 cm in diameter, was detected adjacent to the inner side of the left kidney by abdominal axial computed tomography (CT), which was initially suspected to be a benign lesion; however, a postoperative follow-up CT scan done 5 months later revealed that the lesion had enlarged remarkably to 8 cm in diameter. Thus, total resection was performed under the presumed diagnosis of a malignant retroperitoneal tumor. The tumor was found to be adjacent to the inner portion of the left kidney and covered by Gerota's fascia. As it involved the ileolumbar muscle and had a metastatic lymph node, complete resection was performed. The resected specimen was 8.5 x 6.5 x 5 cm in size and was histologically confirmed as a retroperitoneal rhabdomyosarcoma of embryonal type. Two courses of adjuvant chemotherapy with adriamycin, vincristine, and cyclophosphamide were given, and the patient has shown no signs of recurrence for 2 years since his second operation.