Histology Course S V 12 Department of Pathology, University of Zurich Histology Course

S V 12 hairy cell leukemia, spleen PAS  
  ICD-10: C91.4; ICD-O: 9940/3

50-year-old male with splenomegaly and pancytopenia. Splenectomy.

- The white pulp is completely non-existent.
- There is an increase in red pulp, some pulp strands have been damaged by hair cells. Middle-sized lymphoid cells with kidney-shaped nuclei containing fine chromatin.
- Pseudosinuses and blood islets

The expansion of the red pulp and obstruction of the pulp strands by hair cells leads to increased sequestration of blood in the spleen with consequent pancytopenia.