Clinicopathologic study of two patients with atypical carcinoid of thymus

Objective:To investigate the clinicopathological features of atypicalcarcinoid of thymus.Methods: By means of histological and immunohistochemical metheds,the clinical and pathological features of two cases of atypical carcinoid of thymus were analyzed.Results: Two patients were both male and aged 46 and 55 years.The tumors were locatedat the mediastinum.Histologically,small round epithelial cells were seen.Immunohistochemical study showed that the tumor cells expressed cytokeratin(AE1/AE3),epithelial membrane antinge,neuron specific enolase,chromogranin A,synaptophysin but not CD3,CD5,TdT,CD20.Conclusion: Atypical carcinoid is a rare maligant thymic tumor and may represent a distinct clinicopathologic entity.