Chromosomal imbalances in sporadic neuroendocrine tumours of the thymus

Neuroendocrine (carcinoid) tumours of the thymus are rare neoplasms characterized by a highly malignant clinical behavior. Some of these tumors are associated with MEN1. In this study we evaluated 10 cases of sporadic thymic neuroendocrine tumours using immunohistochemistry and comparative genomic hybridization (CGH). All tumours showed a diffuse expression of neuron specific enolase (NSE) and synaptophysin. Chromosomal imbalances were detected in 8/10 cases, the most frequent gains were seen on chromosome Xp (3/10 cases), 7p, 7q, 11q, 12q, and 20q (2/10 each), losses were most frequently detected at 6q (5/10 each), 6p (3/10 each), 4q (3/10 each), 3p, 10q, 11q and 13 q (2/10 each). These CGH data show a degree of overlap with chromosomal imbalances commonly observed in advanced thymomas.