13 July 2026
: Case report 
Coexistence of Multiple Myeloma, Mast Cell Hyperplasia, and Low-Level Myeloid Blastocytosis: A Report of a Rare Case
Challenging differential diagnosis, Unusual or unexpected effect of treatment, Diagnostic / therapeutic accidents, Rare disease
Meng Yang BEF 1, Qian Wang D 1, Jian Zhang D 1, Hong Jiang E 1, Hongzhi Xu A 1, Kang Lu G 1, Yujie Jiang AG 1*DOI: 10.12659/AJCR.952005
Am J Case Rep 2026; 27:e952005
Table 2 Comparison of laboratory tests between 2021 (initial presentation) and 2024 (re-evaluation) for this patient.
| Initial presentation (2021) | Re-evaluation (2024) | |
|---|---|---|
| Routine blood examination | Elevated WBC and platelet counts, decreased RBC count | Pancytopenia |
| Renal function | Normal | Creatinine 144.4 μmol/L, eGFR 31.0 mL/min |
| BMA/BMB | Plasma cells accounted for 9% | Plasma cells accounted for 10.5%, and mast cells accounted for 10% |
| Flow cytometry | Abnormal plasma cells: CD38 (+), CD56 (+), CD138 (+). | Abnormal plasma cells: were positive for CD38 (+), CD56 (+), and CD138 (+). Myeloid blasts: CD38 (+), CD13 (+), CD45 (+). Mast cells: CD117 (+), CD2 (−), CD30 (−). |
| Mast cell-specific studies | Not tested | Serum tryptase: 19.1 ng/mL KIT D816V mutation: negative |
| Diagnosis | MGUS | MM, mastocytosis, and myeloid blasts |
| WBC: White Blood Cells. RBC: Red Blood Cells. eGFR: estimated Glomerular Filtration Rate. BMA: Bone Marrow Aspirate. BMB: Bone Marrow Biopsy. MGUS: Monoclonal Gammopathy of Undetermined Significance. MM: Multiple Myeloma. | ||