A case of angiosarcoma that developed 10 years after postoperative radiotherapy for tongue cancer

Angiosarcoma is a rare disease that accounts for about l%-2% of all soft-tissue sarcomas and is a highly malignant tumor with a poor prognosis. Albeit not very common, in some cases, angiosarcomas can be induced by irradiation. In this study, we report the case of a patient who developed angiosarcoma at the site of previous postoperative radiotherapy for tongue cancer. The patient was a 63-year-old woman who had undergone surgery for tongue cancer (T4aN2cM0) and received irradiation (50 Gy in total) to the cervical region. The postoperative course had been uneventful, without recurrence. However, 10 years after the surgery, she began to develop a dark-red tumor in the right lower jaw, which was diagnosed as angiosarcoma by biopsy. Because imaging revealed evidence of neither lymph node metastasis nor distant metastasis, tumorectomy with reconstructive surgery using a pectoralis major myocutaneous flap was performed. She then received postoperative adjuvant chemotherapy. Thereafter, she has had an uneventful course, without any evidence of recurrence until date. This case serves to underscore the fact that exposure to radiation can result in new malignant tumor formation. Therefore, such patients need to be explained about the possibility of development of radiation-induced tumor and about the need for long-term follow-up after radiotherapy; they should also receive instructions to visit a medical facility in case they notice any abnormality at the site of previous irradiation. In the event a patient develops any abnormality, such as redness and/or swelling, at the site of previous irradiation, he/she a patient should immediately be worked up under the assumption of not only recurrence of the primary disease, but also possible radiation-induced tumor. The diagnosis must be established by methods such as biopsy.