[Mediastinal and hilar lymph node of cancer unknown origin: 3 case reports].

We encountered three rare cases of cancer of unknown origin affecting the mediastinal and hilar lymph nodes. Patient 1 was a 63 year-old man. Chest X-ray and CT films revealed an enlarged right hilar lymph node. A right mediastinal and hilar lymphadenectomy was performed. The histological diagnosis was metastatic squamous cell carcinoma (SCC). SCC of the right upper lobe appeared 34 months after the operation, requiring a right pneumonectomy. Patient 1 was alive 43 months after his first operation. Patient 2 was a 73 year-old man in whom left mediastinal and hilar lymph node swelling had been detected. A mediastinoscopy and lymph node biopsy were performed. The histological findings resulted in a diagnosis of metastatic small cell carcinoma. Chemotherapy was initiated, and the patient was alive 5 months after the biopsy procedure, Patient 3 was a 57 year-old man in whom right mediastinal and hilar lymph node swelling had been disclosed by chest CT scans. We performed a medianosternotomy and mediastinal and right hilar lymphadenectomy. Histologically, the diagnosis was metastatic adenocarcinoma. After the operation, radiation therapy was performed on the patient's mediastinum. Patient 3 was alive 5 months after the initial operation. The patients were given diagnoses of T0N1 or T0N2 lung cancer.