Case Report
Year: 2021 | Month: January | Volume: 11 | Issue: 1 | Pages: 111-113
Radiation-Induced Sarcoma Post Radiotherapy Treatment of Nasopharyngeal Carcinoma
Sin Wee Lim1,2, Tengku Mohamed Izam Tengku Kamalden1
1Hospital Sultan Ismail, Johor Bahru, Malaysia
2Universiti Malaya Medical Centre, Kuala Lumpur, Malaysia
Corresponding Author: Sin Wee Lim
ABSTRACT
Introduction: Nasopharyngeal carcinoma (NPC) is a squamous cell carcinoma that commonly arises from the Fossa of Rosenmuller. The primary treatment for NPC is radiotherapy, which in long term is known to induce secondary malignancies. Radiation-induced sarcoma (RIS), a late complication of radiotherapy, is a rare tumour with a reported incidence of 0.03-0.8%. Prognosis is poor with a 5-year survival rate of 30%.
Report: Our case is a 65-year-old lady who has completed concurrent chemotherapy and radiotherapy 15 years ago. She presented with 1 month history of painful swelling over the right temporomandibular joint. Initially she was treated as parotitis with a differential of osteoradionecrosis based on orthopantomograph findings. Her swelling increased in size (6x8 cm) and started complaining of trismus and persistent headache. Biopsy was reported as high grade epithelioid sarcoma. CECT neck showed a large heterogeneously enhancing right masticator space mass with intracranial extension. In view of the extent of the disease, patient was counselled for palliative chemotherapy.
Conclusions: The rarity of RIS poses a diagnostic and treatment challenge to clinicians. Early clinical investigation can be difficult due to induration and fibrosis of the irradiated fields. Although new techniques of radiotherapy have been used to minimize the radiation field, outcome of studies comparing new techniques against conventional radiotherapy on incidence of secondary malignancies remains debatable. Studies have shown neither additional radiation nor chemotherapy will improve overall survival. With the improved treatment regime for NPC and variability of RIS latency period, this necessitates lifelong monitoring of NPC patients post radiotherapy.
Key words: Nasopharyngeal carcinoma, radiation-induced sarcoma, radiotherapy.