case_images: PMC10469220_01
case_images: (a-e) H&E staining showed the presence of some lymph node structures with significant hyperplasia of spindle-shaped atypical cells in the interfollicular area, and some spindle cells showed a false follicle-like structure with large amounts of eosinophil infiltration. (f) CD3 showed the residual interfollicular T cells. (g) CD20 showed the residual follicular structure. (h) LCA showed strong positive for residual follicles and weakly positive for spindle cells. (i, j) CD117 showed diffuse strong positive spindle-shaped atypical cells. (k, l) CD25 showed diffuse strong positive for spindle atypical cells. H&E: hematoxylin-eosin; LCA: leukocyte common antigen (CD45).
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case_images: Positron emission tomography-CT (PET-CT) displayed multiple enlarged lymph nodes between interportal lumen and mesenteric roots with the biggest 34.5 x 19.7 mm and SUV 4.48 (Supplemental Figure S1). Immunohistochemistry showed that the spindle-form atypical cells were CD117+ and CD25+ (Figure 1).
case_images: Flowchart showed the changes of blood routine and liver function indexes after avapritinib treatment, including (a) WBC, (b) E, (c) Hb, (d) PLT, (e) GGT, and (f) ALP.. WBC: white blood cells; E: eosinophils; Hb: hemoglobin; PLT: platelet; GGT: glutamyltransferase; ALP: alkaline phosphatase.
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case_images: Bone marrow (BM) smear showed significantly increased eosinophils (19%; Supplemental Figure S2). However, anemia still persisted because of infection and diarrhea (Figure 2).