F 49, anterial mediastinal mass with myasthenia gravis

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F 49, anterial mediastinal mass with myasthenia
gravis
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Normal Thymus
Fibrous septa
Tumor border
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Type B2 Thymoma
Epithelial tumor cells and background immature T
lymphocytes
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Type B2 Thymoma
Epithelial tumor cells (arrows)
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large, polygonal tumour cells that are arranged
in a loose network
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Type B2 Thymoma

• Definition Type B2 thymoma is an organotypical
  thymic epithelial neoplasm composed of large,
  polygonal tumour cells that are arranged in a
  loose network and exhibit large vesicular nuclei,
  closely resembling the predominant epithelial
  cells of the normal thymic cortex. A background
  population of immature T cells is always present
  and usually outnumbers the neoplastic epithelial
  cells
• Synonyms Cortical thymomaLymphocytic thymoma
  (obsolete)Mixed lymphocytic and epithelial
  thymoma (obsolete)