THYMUS AND LUNG - Thymic germinoma

Description of Specimen
The specimen shows part of the upper lobe of the left lung invaded by a mass of tumour occupying the position of the thymus. The tumour measures some 15 x 8 cm; the cut surface shows light tan-coloured tumour tissue in which there are areas of necrosis and of cyst formation. The outer surface is lobulated. The histology of the lesion is that of a germinoma (histologically closely resembling the appearances of testicular seminoma). The tumour was established as invading the adjacent lung and pericardium and tumour tissue was present in one bronchopulmonary lymph node.
This man presented at the age of 22 with some discomfort in the left chest and had recently been under investigation and treatment for nasal allergy symptoms. Radiographically there was an opacity in the anterior mediastinum; two years before an X-ray was reported as within normal limits. The lesion was resected and he remains well.