Case Report: Coexistence of advanced systemic mastocytosis, chronic myelomonocytic Leukemia, and t(11;14)-positive plasma-cell neoplasm: a rare triple-clonal hematologic case
- 1Department of Hematology, Second People’s Hospital of Yibin City
- 2Department of Pathology, Sichuan Kingmed Center for Clinical Laboratory
- 3Hematopathy Diagnosis Center, Sichuan Kingmed Center for Clinical Laboratory
Abstract
Background: SM-AHN usually coexists with myeloid disorders, whereas plasma-cell neoplasms are rare. We report a case of advanced systemic mastocytosis, CMML, and a t(11;14)-positive monoclonal plasma-cell disorder, highlighting the diagnostic challenge of overlapping clinical, biochemical, and morphologic features.
Case presentation: A middle-aged man presented with months of watery diarrhea, recurrent abdominal discomfort, weight loss, markedly elevated alkaline phosphatase, and persistent monocytosis. Bone marrow examination showed dense aggregates of atypical mast cells involving about 50% of marrow cellularity, with aberrant CD25 expression, and KIT D816V (variant allele frequency, 12.10%), supporting advanced systemic mastocytosis. Sustained absolute monocytosis, classical-monocyte predominance up to 98%, and mutations in TET2 , SRSF2 , and RUNX1 supported concurrent CMML-1. Marrow plasma-cell infiltration, markedly elevated lambda free light chains, a low κ/λ ratio, and t(11;14) identified a third clonal process consistent with an IgG lambda plasma-cell neoplasm. Together, these findings established coexistence of advanced SM, CMML, and a plasma-cell disorder, with early symptomatic and biochemical improvement after treatment targeting the mast-cell and myeloid components.
Conclusion: This case highlights the value of integrating morphology, flow cytometry, cytogenetics, and next-generation sequencing in complex hematologic presentations. The coexistence of SM, CMML, and a t(11;14)-positive plasma-cell neoplasm is exceptionally rare, with important implications for diagnosis, risk assessment, and treatment.
Related
- Predicting the clinical course of advanced systemic mastocytosis on treatment with avapritinib or midostaurin
- Outcomes and prognostic factors in patients with systemic mastocytosis and an associated myeloid neoplasm: an international ECNM registry study
- Myeloid-derived suppressor cells in hematologic malignancies: A current state of the field
- 454 Second primary hematologic malignancies in melanoma survivors before and after the introduction of immune checkpoint inhibitors: a population-based SEER analysis
- Eco-evolutionary dynamics of sexually selected infanticide facilitate species coexistence
BibTeX
@article{yin2026case,
title = {{Case Report: Coexistence of advanced systemic mastocytosis, chronic myelomonocytic Leukemia, and t(11;14)-positive plasma-cell neoplasm: a rare triple-clonal hematologic case}},
author = {Jun Yin and Jingyuan Luo and Linlin Huang and Ling Wang and Mingwei Zhong and Maoqin Li and Shihua Huang},
journal = {Frontiers in Oncology},
year = {2026},
month = oct,
doi = {10.3389/fonc.2026.1982665},
url = {https://www.frontiersin.org/articles/10.3389/fonc.2026.1982665/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Case Report: Coexistence of advanced systemic mastocytosis, chronic myelomonocytic Leukemia, and t(11;14)-positive plasma-cell neoplasm: a rare triple-clonal hematologic case
AU - Jun Yin
AU - Jingyuan Luo
AU - Linlin Huang
AU - Ling Wang
AU - Mingwei Zhong
AU - Maoqin Li
AU - Shihua Huang
PY - 2026
DA - 2026/10/19
JO - Frontiers in Oncology
DO - 10.3389/fonc.2026.1982665
UR - https://www.frontiersin.org/articles/10.3389/fonc.2026.1982665/full
AB - Background: SM-AHN usually coexists with myeloid disorders, whereas plasma-cell neoplasms are rare. We report a case of advanced systemic mastocytosis, CMML, and a t(11;14)-positive monoclonal plasma-cell disorder, highlighting the diagnostic challenge of overlapping clinical, biochemical, and morphologic features. Case presentation: A middle-aged man presented with months of watery diarrhea, recurrent abdominal discomfort, weight loss, markedly elevated alkaline phosphatase, and persistent monocytosis. Bone marrow examination showed dense aggregates of atypical mast cells involving about 50% of marrow cellularity, with aberrant CD25 expression, and KIT D816V (variant allele frequency, 12.10%), supporting advanced systemic mastocytosis. Sustained absolute monocytosis, classical-monocyte predominance up to 98%, and mutations in TET2 , SRSF2 , and RUNX1 supported concurrent CMML-1. Marrow plasma-cell infiltration, markedly elevated lambda free light chains, a low κ/λ ratio, and t(11;14) identified a third clonal process consistent with an IgG lambda plasma-cell neoplasm. Together, these findings established coexistence of advanced SM, CMML, and a plasma-cell disorder, with early symptomatic and biochemical improvement after treatment targeting the mast-cell and myeloid components. Conclusion: This case highlights the value of integrating morphology, flow cytometry, cytogenetics, and next-generation sequencing in complex hematologic presentations. The coexistence of SM, CMML, and a t(11;14)-positive plasma-cell neoplasm is exceptionally rare, with important implications for diagnosis, risk assessment, and treatment.
SN - 2234-943X
ER -