How We Manage Patients with Plasmacytomas

Bone-Related Extramedullary Disease in Newly Diagnosed Myeloma Patients is an Independent Poor Prognostic Predictor

Background

Bone-related extramedullary disease (EMD-B) is mass of clonal plasma cells derived from adjacent bone lesions and has obvious heterogeneities in clinical outcomes. This retrospective study aims to evaluate the treatment outcomes and long-term prognosis of newly diagnosed myeloma patients with EMD-B.

Methods

This was a retrospective study conducted in Beijing Chaoyang Hospital from January 1, 2010 to December 31, 2019. Seventy-seven newly diagnosed multiple myeloma patients with EMD-B were selected. Propensity score matching (1:2) was used to match patients with and without EMD-B. After matching, 132 patients without extramedullary disease (non-EMD) were included in the study. All patients received bortezomib-based regimens as induction therapy.

Results

After matching, baseline data of the 2 groups were comparable. The Cox regression analysis of patients with EMD-B showed that age, paravertebral lesions, and immunoglobulin D (IgD) type may have adverse effects on survival. Bone-related extramedullary disease at new diagnosis was a risk predictor of survival (hazard ration [HR] = 1.80, 95% confidence interval [CI]: 1.09-2.98, P = .022). The median survival time of the EMD-B group was significantly shorter than that of the non-EMD group (52 months vs 96 months, P = .043). Induction therapy did not show any significant differences in effectiveness between the 2 groups. Autologous stem cell transplantation (ASCT) significantly increased complete remission rate of patients with EMD-B (EMD-B vs non-EMD: no ASCT 15.7% vs 31.9%, P = .035; ASCT 42.3% vs 48.8%, P = .626) and improved their median overall survival rate (EMD-B vs non-EMD: no ASCT 49 months vs 75 months, P = .003; ASCT not reached vs 96 months, P = .505).

Conclusions

This study demonstrated that newly diagnosed myeloma patients with EMD-B had poor outcomes, which could be improved by ASCT.

An Unusual Case of Multiple Myeloma with Light-Chain Cast Nephropathy Secondary to a Very Large Plasmacytoma without Bone Marrow Involvement

Here, we report a case of a patient who presented to Strong Memorial Hospital with new-onset renal failure and anemia and was found to have multiple myeloma with lambda light-chain cast nephropathy secondary to a very large (14 cm × 14 cm × 12 cm) plasmacytoma without bone marrow involvement. This case is notable as solitary plasmacytomas are almost never seen with concomitant myeloma-defining CRAB criteria or significantly elevated serum free light-chain ratios. Although solitary plasmacytomas are typically definitively treated with radiation, this case highlights that systemic treatment may be helpful in certain clinical scenarios.

Extramedullary Plasmacytoma Causing Myelopathy Resulting in Gait Imbalance

Plasmacytomas are neoplasms of plasma cells that can involve the bone marrow, the bone itself, or soft tissue without bone marrow involvement. Extramedullary plasmacytomas are most commonly found in the upper respiratory tract in a total of 80% of all cases. Extramedullary plasmacytomas have also been documented in locations such as the central nervous system. This form of plasmacytoma may be seen as a solitary entity or in patients with multiple myeloma. We present a case of a 66-year-old female with a history of multiple myeloma on maintenance therapy with lenalidomide who has been experiencing gait imbalance for the past two months. The patient had a thoracic MRI done that revealed a mass at T7-8 with associated cord compression. She was taken for surgical intervention by neurosurgery. Pathology revealed trabecular bone and cartilage infiltrated by sheets of plasma cells highlighted by immunostaining CD138, monoclonal lambda light chains, consistent with a plasma cell neoplasm (plasmacytoma). The patient’s hospital course was complicated by hypotension resulting in transient ischemic myelopathy that was addressed in the neuro-intensive care unit. The patient was then discharged to an inpatient rehabilitation center. She would follow up with her primary oncologist for localized radiation therapy.

Maximizing the Clinical Benefit of Radiotherapy in Solitary Plasmacytoma: An International Multicenter Analysis

Objective: Although local definitive radiotherapy (RT) is considered the standard of care for solitary plasmacytoma (SP), the optimal RT parameters for SP patients have not been defined. The aim of this retrospective study is to analyze the effectiveness of various RT doses, volumes, and techniques, as well as to define the relevant prognostic factors in SP. Methods: Between 2000 and 2019, 84 patients, including 54 with solitary bone plasmacytoma (SBP) and 30 with extramedullary plasmacytoma (EMP), underwent RT at six institutions. Results: The overall RT median dose was 42 Gy (range, 36.0–59.4). The median follow-up period was 46 months. Overall, the local control (LC) rate was 96%, while the complete remission (CR) rate was 46%. The 5-year local relapse-free survival (LRFS), multiple myeloma-free survival (MMFS), progression-free survival (PFS), and overall survival (OS) rates were 89%, 71%, 55%, and 93%, respectively. Using an RT dose above 40 Gy was associated with a higher complete remission (CR) rate and a lower rate of local relapse. Modern irradiation techniques were associated with a trend toward a higher LC rate (98% vs. 87% for conventional, p = 0.09) and a significantly lower local relapse rate (6% vs. 25% for conventional, p = 0.04). However, RT dose escalation and technique did not lead to a significant effect on MMFS, PFS, and OS. Univariate analyses identified several patient characteristics as potentially relevant prognostic factors. In SBP patients, systemic therapy administration was associated significantly with MMFS and PFS rates. Conclusion: Using an RT dose >40 Gy and modern RT techniques may improve the local control and reduce the rate of relapse, without a significant impact on survival rates. The addition of systemic therapies may improve the MMFS and PFS rates of SBP patients.