HISTOPATHOLOGY

Microscopic description
- Atypical lymphoid cells (lymphoblasts) of small and intermediate size and having irregular, nucear cntours, dispersed chromatin, inconspicous nucleoli and scant cytoplasm. These cells are immunoreactive to CD3, CD5, CD10 and TdT; however, they are immunonegative to CD20, PAX5 and CD34. The proliferation index (Ki-67) is >90%.

Diagnosis
- T-cell lymphoblastic lymphoma.