Solitary plasmacytoma: 10 years’ experience at All India Institute of Medical Sciences, New Delhi

Reossification and prognosis following radiotherapy with/without surgery for spinal solitary plasmacytoma of the bone: a retrospective study of 39 patients

BACKGROUND CONTEXT

Solitary plasmacytoma of bone (SPB) can progress to multiple myeloma (MM). Little attention has been paid to the reossification findings on computed tomography (CT) and their correlation with prognosis after radiotherapy with/without surgery.

PURPOSE

To evaluate reossification after radiotherapy and prognostic factors of spinal SPB using single-center data.

STUDY DESIGN

Retrospective observational study.

PATIENT SAMPLE

Patients who had spinal SPB and received radiotherapy with/without surgery, without chemotherapy, denosumab or zoledronic acid.

OUTCOME MEASURES

MM progression rate, mortality rate, and reossification rate at 12 months.

METHODS

This retrospective clinical review included 39 patients who underwent radiotherapy as first-line treatment for SPB in the spine. External radiation was divided into 20-25 fractions with a total dose of 35-46 Gy. At the 12-month follow-up after the index radiotherapy, significant and mild reossification, defined as bone formation with ≥30% or 0%-30% increase, respectively, in bony area based on increase in CT values were documented, along with progressive disease, which was a decrease in bony area with lesion enlargement. This study was funded by AO Foundation, AOSpine (AOSDIA2019-026) (CHF45,000), Peking University Medicine Seed Fund for Interdisciplinary Research (BMU2018MX022) (¥40,000), and Peking University Third Hospital (No. Y71508-01) (¥400,000).

RESULTS

Twenty-six men and 13 women (mean age, 51.5 years) were included. Solitary plasmacytomas were located in the cervical, thoracic, and lumbar vertebrae in 16, 17, and 6 patients, respectively. The mean clinical follow-up period after treatment was 72 (range 12-216) months. Sixteen patients (41.0%) had significant reossification after radiotherapy, 21 (53.8%) showed mild reossification, and 2 (5.2%) had progressive bony destruction (after 7 and 23 months, respectively). There were no significant differences in age among the three groups (p=.127). At a mean follow-up of 37 (range 6-90) months after radiosurgery, 14 (35.8%) patients developed MM, including 9 patients who died at a mean duration of 55 (range 19-102) months. In the significant reossification group, only 1 patient (6.3%, 1 of 16) had MM progression 82 months after treatment (p=.044). In the mild reossification group, 56.5% (13 of 23) of patients had MM progression. The significant reossification rates of the radiotherapy dose groups of <40 Gy and ≥40 Gy were 35.7% and 44% (p=.614), respectively. In the univariate analysis, age ≥65 years (p<.001), tumor ≥5 cm (p=.009), Spinal Instability Neoplastic Score scores ≥11.5 (p=.040), radiotherapy (RT) combined with surgery (p<.001), and progression to MM (p=.007) were the independent prognostic factors for overall survival; whereas, age >44 years (p=.045) and RT combined with surgery (p<.001) were for multiple myeloma-free survival. In the multivariate analyses, age >65 years (p=.004) and progression to MM (p=.007) were the unfavorable independent factors for overall survival, whereas RT combined with surgery (p=.004) was the only factor for multiple myeloma-free survival.

CONCLUSIONS

In patients with spinal SPB, 41.0% lesions showed significant reossification after radiotherapy. Patients with significant reossification had a better prognosis with less possibility of MM progression. Radiotherapy may be a safe and effective treatment choice for spinal SPB; more attention should be paid to reossification.

Clinicopathological spectrum of solitary Plasmacytoma: a single center experience from coastal India

Background

Plasma cell disorders are a rare group of hematological malignancies that accounts for 10% of all hematological neoplasms. Solitary plasmacytomas are rarer entities accounting for less than 5% of all the plasma cell dyscrasias. They encompass three subtypes - Solitary Plasmacytoma of Bone (SPB) and Solitary Extramedullary Plasmacytoma (SEP) and multiple solitary plasmacytomas (MSP). In this study, we discuss the clinical, histopathological and immunohistochemical characteristics of solitary plasmacytomas.

Methods

A 13 year retrospective analysis of solitary plasmacytomas was performed from a single tertiary care center. Bone marrow evaluation was done concurrently at the time of diagnosis to rule out the presence of multiple myeloma.

Results

A total of 29 cases fulfilled the diagnostic criteria for SP during the study period. SPB accounted for 55.2%, SEP for 44.4% and MSP for 3.4% of the cases. The most common sites involved were the paranasal sinuses and vertebrae. Other infrequent sites included lymph node, tonsil and lungs. The mean age of presentation of SPB was a decade later than SEP. A male preponderance was observed in both subtypes.

Conclusion

Solitary plasmacytoma is a rare entity, the diagnosis of which requires a systematic approach. There is limited data available in the literature on the clinico-pathological characteristics of SP from India.

Long-term outcome of patients with solitary plasmacytoma treated with radiotherapy: A population-based, single-center study with median follow-up of 13.7 years

In this single-center, population-based, and retrospective study, we analyzed the outcome of 49 patients with solitary bone plasmacytoma (SBP) and 28 patients with solitary extramedullary plasmacytoma (SEP), all treated with radiotherapy. Laminectomy was performed in 18/30 SBP patients with vertebral involvement and tumour resection in 10 SEP patients. Overall survival and cause of death for each patient were compared to 5 sex-, age-, and residency-matched individuals from the normal population. Response (complete and partial) was achieved in 94% of SBP and 96% of SEP patients. Relapse rates were higher in SBP (65%) compared to patients with SEP (18%) (P < .01). Only one in-field relapse was identified for the whole series. Ten- and 15-year overall survival, progression free survival (PFS) and multiple myeloma free survival (MMFS) for patients with SBP were 60%/41%, 25%/17%, and 33%/33%. Corresponding values for patients with SEP were 67%/54%, 57%/44%, and 91%/91%. SBP patients had significantly shorter PFS and MMFS compared to SEP patients (P < .01 for both). Only two of the SEP patients developed multiple myeloma and no patient in the whole series progressed to multiple myeloma later than 10 years after diagnosis. Unlike for SEP, the major cause of death among SBP patients was multiple myeloma (49%). Compared to matched normal population, no increased risk of death from secondary malignancies or cardiovascular disease was observed. Positive predictors in SBP patients were for overall survival age <60 years, combined laminectomy and radiotherapy and radiotherapy dose >40 gray, for PFS tumour size <6 cm and combined laminectomy and radiotherapy and for MMFS tumour size <6 cm. Radiotherapy confers excellent local control in both SEP and SBP patients; however, the challenge is to prevent development of multiple myeloma in patients with SBP.

Presentation and Outcome of Castleman's Disease in Immunocompetent Hosts

Castleman's disease (CD) is a heterogeneous lymphoproliferative disorder of unknown aetiology. Mostly, this disorder is seen in immunocompromised hosts. It is known to be associated with systemic disorders like HIV, HHV-8, lymphoma, and Kaposi sarcoma. As of today, the clinical behaviour and outcome of CD in immunocompetent host remains suboptimally studied. We analyzed consecutively treated cases of CD presented to our centre in last 12 years. Case record files were studied for patient's characteristics, clinical presentation, baseline laboratory and pathologic parameters, therapy and outcome. This study describes presentation and treatment outcome of CD in immunocompetent patients. Total 16 patients of CD were treated during the study period. The median age of patients at the time of presentation was 40.5 years (range 13-72 years). An equal number of patients (8 each) had unicentric and multicentric CD. Sixty-three percent patients had hyaline vascular subtype while 37 % patients had plasma cell or mixed variant. Majority of the patients had good performance status (ECOG PS 0, 1 in 10 (62.5 %) patients; PS2-4 in 6 (37.5 %) patients). The median duration of symptoms was 6 months (range 2-36 months). None of the patients in our study had associated HIV infection. Six patients presented with fever, out of which four had plasma cell variant of CD and three of them had multicentric involvement. In comparison to unicentric CD, patients with multicentric CD had lower albumin levels (4.15 vs. 3.38 g/dl, p = 0.006), haemoglobin levels (11.3 vs. 9.8, p = 0.06), and lower complete remission rates (62.5 % vs. none). Patients were treated according to the stage and clinical status with surgery, chemotherapy or combination of both modalities. Surgery was the predominant treatment for unicentric CD while multicentric CD was treated with various chemotherapy regimens. Eight patients were treated with chemotherapy (CHOP-based regimen-5, melphalan-prednisolone thalidomide-1, chlorambucil-prednisolone-1, and only corticosteroids-1). In the entire study group, ORR was 72 % (CR 36 %, PR 36 %), one patient died of progressive disease during chemotherapy. Two patients lost to follow-up before assessment of treatment response. Five-year overall survival was 100 and 87 % for unicentric and multicentric CD respectively. Castleman's disease is a rare lymphoproliferative disorder amongst Indian patients. It more commonly presents as hyaline vascular variant and affects middle-aged individuals. The most remarkable fact in our analysis was a lack of HIV positivity in any of the patient that is in contrast to the majority of the published literature. With multimodality therapy, high response rates and long-term survival were noted in the entire study group.

Prognostic factors associated with solitary plasmacytoma

Solitary plasmacytoma (SP) is a rare tumor with low incidence. The aim of this study was to investigate the clinical features, treatment strategies, and relative prognostic factors of 66 patients with SP. These patients made up 10.25% of the 644 patients with plasma cell dyscrasias treated at the Tianjin Medical University Cancer Institute and Hospital over the past 12 years. SP always presented with either solitary bone plasmacytoma (SBP) or extramedullary plasmacytoma (EMP), as determined by the location of the lesions. SBP occurred most frequently in the vertebral column and EMP in the upper respiratory tract. In addition to other factors, tumor size, serum M protein level, urinary Bence Jones protein level, and disease progression toward multiple myeloma were significantly different between the two groups (P<0.05). Larger tumor size (≥5 cm) was associated with poor prognosis of local control, multiple myeloma–free survival, overall survival and progression-free survival for SBP patients. Radiotherapy and serum β₂ microglobulin <3.5 mg/L were favorable prognostic factors for local control, multiple myeloma-free survival, and progression-free survival in patients with EMP.