RAPID APPEARANCE OF RHABDOMYOSARCOMA AFTER RADIATION AND CHEMOTHERAPY FOR RETINOBLASTOMA: A CLINICOPATHOLOGIC CORRELATION

Abstract

Purpose: To report a clinicopathologic correlation of rhabdomyosarcoma appearing rapidly after external beam radiotherapy (EBRT) and systemic chemotherapy for bilateral retinoblastoma (RB) and compare this case with previously reported secondary rhabdomyosarcomas in RB survivors. Methods: We studied the case of a patient with bilateral RB who developed a rhabdomyosarcoma in the field of radiation after treatment with systemic chemotherapy and EBRT. We compared the timecourse of onset of rhabdomyosarcoma in this case to data from the largest two series of radiation-related rhabdomyosarcomas in RB patients. We correlated the pathology of the rhabdomyosarcoma with the clinical findings. Results: A rhabdomyosarcoma presented in the temporalis muscle of the patient 2 years, 8 months after RB diagnosis and 2 years following EBRT. This patient had a shorter latency period after diagnosis and treatment than the patients in the two previously reported large series. Conclusion: This case report illustrates the unusually early presentation of a rhabdomyosarcoma within the radiation field in a germinal RB survivor. Clinicians should be aware that unusual secondary malignancies can present after EBRT. Patients should be screened routinely for secondary malignancies soon after treatment for the initial cancer.