Abstract
Background. Recent advances in cancer therapy and diagnostic technology have improved the chances of successfully treating multiple primary cancers. Case. A 64-year-old man had undergone treatment for sigmoid colon cancer and an abdominal tumor 1 year previously. Histopathologically, the cancer was diagnosed as being moderately differentiated adenocarcinoma, whereas the abdominal tumor was diagnosed as to be metastatic neuroendocrine carcinoma of unknown origin. Six months after treatment, chest computed tomography revealed the presence of a small nodule in the right upper lobe of the lung. Another 5 months later, the nodule had increased in size and the patient presented with a swollen lower paratracheal lymph node. A high accumulation of fluorodeoxyglucose was observed in the nodule and lymph node on positron emission tomography. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) from the lower paratracheal lymph node confirmed metastatic lung adenocarcinoma. We performed a right upper lobectomy along with the dissection of the systematic lymph node, following which a histopathological diagnosis of lung adenocarcinoma, pT2aN2M0 stage IIIA was reached. Conclusion. The findings of this study demonstrate the importance of histopathologically diagnosing a newly arising tumor after previous cancer treatment, particularly in cancers of unknown origin. EBUS-TBNA is a safe and useful diagnostic procedure for multiple primary cancers.
