Papillary carcinoma thyroid as a second malignant neoplasm following radiotherapy for medulloblastoma in childhood: A rare case report

Abstract

Second malignant neoplasm is a rare but dreaded late sequelae of the treated primary childhood malignancies. Surgical excision combined with radiochemotherapy represents the gold standard of therapy for medulloblastoma. The effectiveness of such a combined treatment has encouraged the use of radiotherapy even in young pediatric patients, in spite of the increased risk of a second radio-induced malignancy. Irradiation is the well-known risk factor for the development of benign and malignant thyroid tumors. Children are more exposed to this risk because their thyroid gland is more sensitive to the carcinogenic effect of ionizing radiation. We report the case of a 20-year-old male who initially presented at the age of 2 years with a medulloblastoma and was treated with surgery and radiotherapy. The patient again presented 18 years after radiotherapy with bilateral neck masses which proved to be lymphadenopathy secondary to papillary carcinoma of the thyroid. The patient also had multiple bilateral metastatic pulmonary nodules. Radio-induced thyroid tumors are well-recognized nosographic entities due to the particular sensitivity of this gland to ionizing radiations. However, only a few papers on radio-induced thyroid neoplasms after the central nervous system (CNS) irradiation have been published in the literature. We report an additional case of thyroid neoplasm following childhood CNS irradiation for the treatment of posterior fossa medulloblastoma and emphasize that clinicians should judiciously use the radiotherapy for treatment of childhood malignancies and also radiologists should be familiar with the long-term complications of antineoplastic therapies to facilitate early diagnosis and treatment.

Keywords

• Computed tomography
• medulloblastoma
• radiation therapy
• second malignant neoplasm