muhiple primary tumors的用法和樣例：
例句
- For instance, some patients are diagnosed with metastased tumours without the primary tumour every being found.
比如說，一些患者在沒有找到原發腫瘤就被診斷為轉移癌。 - The nasopharynx is the most common primary site in cerebral radionecrosis of extracranial malignancies, followed by the scalp and sinonasal tract.
鼻咽是最常見的原發腫瘤部位，接下來依序是頭皮以及鼻竇。
