Ras-associated autoimmune leukoproliferative disorder: histopathological and flow cytometry findings

(A) Splenic parenchyma with marked congestion of red pulp; hematoxylin and eosin (HE) stained 200x. (B) Splenic hilar lymph node showing sinus histiocytosis; HE stained 200X. (C) Bone marrow biopsy with significant myeloid hyperplasia (myeloid-erythroid ratio 10:1), accompanied by an increase in morphologically normal eosinophils (arrows); HE stained 400X. (D) CD64+ monocyte gating (right) and assessment of CD16 expression in peripheral blood cytometry, along with corresponding distribution of monocyte subtypes (left): classical monocytes (CD14+, CD16-) accounted for 83.9% (light green); intermediate monocytes (CD14+, CD16+) comprised 15.8% (dark green); and non-classical monocytes (CD14+ weak, CD16+) represented 0.3% (purple). (E) Atypical expression of CD14 in the neutrophilic granulocyte population (green) in peripheral blood cytometry. (F) Peripheral blood cytometry gate in total lymphocytes and evaluation of circulating CD10+ B cells (blue).