Bone marrow morphologic features, MyPRS, and gene mutation correlations in plasma cell myeloma

Aberrant Acquisition of T-cell Associated Markers in Plasma Cell Neoplasms: An Aggressive Disease with Extramedullary Involvement and Very Short Survival

Background

Plasma cell neoplasms can show aberrant expression of different lineage-related antigens; however, co-expression of T-cell-associated markers on malignant plasma cells is extremely rare.

Material and methods

This report describes clinicopathologic characteristics of three myeloma patients with emergent plasmablastic morphology and aberrant acquisition of T-cell-associated markers diagnosed in our center. An extensive literature search for similar cases was conducted, and the relevant pathologic, clinical, and prognostic characteristics were summarized.

Results

A total of 22 cases of plasma cell neoplasm (including the three cases reported here) showed aberrant co-expression of T-cell markers. We found an evident association between aberrant expression of T-cell markers on malignant plasma cells and extramedullary involvement, aggressive morphologic features, high proliferative index ki67 >90%, aggressive clinical course, an adverse outcome, and short survival.

Discussion & Conclusion

Due to the rarity of this aberrant phenotype and scarcity of the published data, the precise causative mechanism and its clinical implications have not yet been elucidated.

Plasma Cell Myeloma with an Aggressive Clinical Course and Anaplastic Morphology in a 22-Year-Old Patient: A Case Report and Review of Literature

BACKGROUND Plasma cell myeloma is a neoplastic plasma cell disorder that usually presents after the fifth decade of life; it is rarely described in younger population especially under 30 years of age. However, there are conflicting reports in the literature about the clinical behavior and overall survival in younger age groups. In approximately 2% of plasma cell myeloma, the morphology of the neoplastic cells is highly pleomorphic, quite anaplastic, and may resemble metastatic tumor cells. While this poses a challenge for morphological interpretation during diagnosis, it has been demonstrated that bone marrow morphologic features (including diffuse sheet growth pattern, immature cell morphology and high mitotic index) significantly correlates with high risk disease. Moreover, there is limited description available about the morphology of the neoplastic cells when correlating the age at presentation with the clinical outcome/biological behavior; hence, the need to report and collect such cases. CASE REPORT We report a case of plasma cell myeloma in a 22-year-old male who presented with non-specific clinical features and posed a diagnostic challenge during clinical, radiological, and laboratory examination. The pathology specimens showed anaplastic morphology. Unfortunately, after diagnosis, despite treatment with brotezomib, his disease had an aggressive clinical course and he passed away 4 months after diagnosis. CONCLUSIONS Although plasma cell myeloma is rare in patients younger than 30 years, it must be considered in the differential diagnosis and investigated properly especially in patients with clinical suspicion of a metastatic non-hematological tumor. The anaplastic variant in a young patient is a diagnostic challenge and is associated with bizarre morphology, aggressive presentation, adverse cytogenetics, resistance to chemotherapy, and poor, short-term, survival.