Adult neuroblastoma arising in the superior mediastinum.

Adult onset neuroblastoma arising in the mediastinum, except posterior mediastinum is extremely rare. We report a case of surgically resected neuroblastoma in the superior mediastinum. A 64-year-old male was admitted to a local hospital, after an abnormal shadow had been detected on a chest radiogram on a routine medical checkup. Computed tomography (CT) examination revealed the tumor located in the superior mediastinum. Preoperatively, we suspected malignant lymphoma or lymph node metastasis from an unknown primary site. We resected the mediastinal tumor for both definitive diagnosis and local treatment. The tumor was composed of sheets of small round cells positive for CD56, NSE, chromogranin A, and vimentin, but negative for AE1/3, CK5/6, CK7, CD3, CD20, CD79a, c-kit, S-100, SMA and CD99. N-myc gene amplification was also confirmed and supported diagnosis of neuroblastoma. Chest CT seven months after surgery revealed multiple recurrences in lymph nodes.