https://orcid.org/0000-0002-2061-1824
![A 22-year-old woman presented with fatigue and leukocytosis without organomegaly and a referral diagnosis of chronic myeloproliferative neoplasm without BCR::ABL1 translocation or JAK2 mutation. Complete blood count showed leukocytosis (white blood cell [WBC], 21.8 × 109/L), anemia (hemoglobin, 11.1 gm/dL), and thrombocytopenia (platelets, 114 × 109/L) with neutrophilia (15.9 × 109/L), eosinophilia (1.74 × 109/L), and rare circulating blasts. Bone marrow (BM) biopsy was hypercellular (∼100%) with myeloid hyperplasia, atypical megakaryocytic hyperplasia, and clusters of foamy histiocytes (panel A, ×400, hematoxylin-eosin stain) highlighted with periodic acid–Schiff stain with fast green counterstain (panel B, ×400). BM smears showed left-shifted myeloid hyperplasia with numerous pseudo-Gaucher cells/sea blue histiocytes with abundant blue and variably lamellar cytoplasm (panel C; ×1000, Wright-Giemsa). Karyotyping detected a t(5;12) (panel D), and fluorescence in situ hybridization confirmed the presence of PDGFRB (panel E) and ETV6 rearrangement in 78% of analyzed cells. The patient was treated with imatinib (400 mg daily) and achieved remission with a WBC of 8.9 × 109/L at 1-month follow-up.](https://ash.silverchair-cdn.com/ash/content_public/journal/blood/140/6/10.1182_blood.2022016602/3/m_bloodbld2022016602f1.png?Expires=1766236076&Signature=b~of8KTvok5dkA43N70izmzNYX-KviN-0UbUXSRt38HpLiW2bQcrj3hPrL3OPYaBbB0UFqtK6xuHZgs5hvm6KnaC7UuERUHRQ2ne7IMbvytEh-30UE5dEG1-qZLpdgO8jglUz-bkA~Zwa994CRw9b9yqIlTjyGXBKWVP~1FY8YuajXJhzybtErtcrTPcXwMJ-4U1iBQITCfRFoN0QmabM1~kAIn-iQaLkPvMeIR-I-FxXVNkBdewkcb3xaD-1R5kv9rGLQRsuGqgaIQwKdQqmyVp3tpCqGeU9aLQek33dJHlSkVsqew79hcEz2wJwioQkIH72BGlNjMswQxya~Whzg__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
A 22-year-old woman presented with fatigue and leukocytosis without organomegaly and a referral diagnosis of chronic myeloproliferative neoplasm without BCR::ABL1 translocation or JAK2 mutation. Complete blood count showed leukocytosis (white blood cell [WBC], 21.8 × 109/L), anemia (hemoglobin, 11.1 gm/dL), and thrombocytopenia (platelets, 114 × 109/L) with neutrophilia (15.9 × 109/L), eosinophilia (1.74 × 109/L), and rare circulating blasts. Bone marrow (BM) biopsy was hypercellular (∼100%) with myeloid hyperplasia, atypical megakaryocytic hyperplasia, and clusters of foamy histiocytes (panel A, ×400, hematoxylin-eosin stain) highlighted with periodic acid–Schiff stain with fast green counterstain (panel B, ×400). BM smears showed left-shifted myeloid hyperplasia with numerous pseudo-Gaucher cells/sea blue histiocytes with abundant blue and variably lamellar cytoplasm (panel C; ×1000, Wright-Giemsa). Karyotyping detected a t(5;12) (panel D), and fluorescence in situ hybridization confirmed the presence of PDGFRB (panel E) and ETV6 rearrangement in 78% of analyzed cells. The patient was treated with imatinib (400 mg daily) and achieved remission with a WBC of 8.9 × 109/L at 1-month follow-up.
Sea-blue histiocytes and pseudo-Gaucher cells are a hallmark of increased cell turnover and characteristically associated with chronic myeloid leukemia BCR::ABL1+. To our knowledge, this is the first report describing increased pseudo-Gaucher cells in association with a myeloid neoplasm with eosinophilia and PDGFRB rearrangement, expanding the spectrum of this morphologic finding.
A 22-year-old woman presented with fatigue and leukocytosis without organomegaly and a referral diagnosis of chronic myeloproliferative neoplasm without BCR::ABL1 translocation or JAK2 mutation. Complete blood count showed leukocytosis (white blood cell [WBC], 21.8 × 109/L), anemia (hemoglobin, 11.1 gm/dL), and thrombocytopenia (platelets, 114 × 109/L) with neutrophilia (15.9 × 109/L), eosinophilia (1.74 × 109/L), and rare circulating blasts. Bone marrow (BM) biopsy was hypercellular (∼100%) with myeloid hyperplasia, atypical megakaryocytic hyperplasia, and clusters of foamy histiocytes (panel A, ×400, hematoxylin-eosin stain) highlighted with periodic acid–Schiff stain with fast green counterstain (panel B, ×400). BM smears showed left-shifted myeloid hyperplasia with numerous pseudo-Gaucher cells/sea blue histiocytes with abundant blue and variably lamellar cytoplasm (panel C; ×1000, Wright-Giemsa). Karyotyping detected a t(5;12) (panel D), and fluorescence in situ hybridization confirmed the presence of PDGFRB (panel E) and ETV6 rearrangement in 78% of analyzed cells. The patient was treated with imatinib (400 mg daily) and achieved remission with a WBC of 8.9 × 109/L at 1-month follow-up.
Sea-blue histiocytes and pseudo-Gaucher cells are a hallmark of increased cell turnover and characteristically associated with chronic myeloid leukemia BCR::ABL1+. To our knowledge, this is the first report describing increased pseudo-Gaucher cells in association with a myeloid neoplasm with eosinophilia and PDGFRB rearrangement, expanding the spectrum of this morphologic finding.
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