Hyalinizing Clear Cell Carcinoma as a Secondary Malignancy in a Childhood Survivor of Rhabdomyosarcoma

Secondary malignancies are an infrequent but well-known phenomenon whereby radiation treatment may predispose a patient to a subsequent malignant neoplasm years after his or her initial diagnosis. The head and neck is a common site for post radiation carcinomas including salivary gland tumors such as mucoepidermoid carcinoma (MEC), acinic cell carcinoma, and even (more recently described) mammary analogue secretory carcinoma (MASC). Hyalinizing clear cell carcinoma (HCCC) is a rare, low-grade carcinoma of the minor salivary glands with characteristic histologic and molecular findings. We report a case of HCCC of the lower lip arising as a secondary malignancy in a 40-year-old woman with a history of childhood rhabdomyosarcoma for which she received radiation therapy. To our knowledge, this report represents the first instance of HCCC being presented as a secondary head and neck malignancy. This case contributes to the spectrum of post radiation carcinomas and highlights the persistent risk of subsequent malignancies in childhood cancer survivors.