A 63-year-old female patient comes to the doctor

because of worsening fatigue, and she has recently lost a lot of weight unintentionally.

She has occasional pain in her left lower back and often feels full after

eating. During physical examination, the woman is subfebrile and relatively large

splenomegaly (enlarged spleen) is present. The blood count shows marked

leukocytosis with a left shift in neutrophils, eosinophilia, basophilia as

well as thrombocytopenia and anemia. Cytogenetic examination of the bone marrow

aspirate demonstrates the presence of the Philadelphia chromosome and further

examination confirms the diagnosis of chronic myeloid leukemia, which in this

patient is associated with hypersplenism, i.e., excessive function of the

spleen, which increasingly destroys red blood cells. In which part of the

spleen does this red blood cell destruction take place?