Quiz WHAT IS YOUR DIAGNOSIS?

Patient: 37-year-old Caucasian female, white-collar worker.
Symptoms: chronic malaise, muscle weakness, recurrent headache and somnolence.
Anamnesis: smoking period of 5 years, an episode of rash as an allergy to penicillin, episodes of depression, two children (cesarean section), appendectomy. She did not lose weight. She was exposed to stress in her work environment. In some work situations she felt the sensation of stinging and crushing behind the sternum.
Physical examination: except for scars after cesarean section and after appendectomy, no abnormalities.
Computed tomography: An oval tumor sized 65 × 47 × 53 mm with smooth contours in the upper anterior mediastinum. The remaining mediastinal and lung hilum lymph nodes were not enlarged. The computed tomography image suggested thymoma.
Microscopic images: Histological examination was much more difficult due the fact that almost the entire tumor was necrotically changed. Apart from fragments of thymus and extensive karyorrhectic necrosis in inflammatory infiltrate consisted of histiocytes, plasma cells and lymphocytes. In addition, immunohistochemistry was performed: Bcl-2 (+); EMA(–); CD3(+); CD20(+); CD68(+) and Ki-67 (+) in single cells.