Progression of a solitary plasmacytoma to multiple myeloma. A population-based registry of the northern Netherlands

Sphenoid plasmacytoma as initial presentation of multiple myeloma-case report

Plasmacytoma is a rare plasma cell neoplasm. Whether solitary or associated with multiple myeloma (MM), it rarely involves the skull base, particularly the sphenoid bone. We present a unique case of sphenoid bone plasmacytoma secondary to MM, highlighting diagnostic and therapeutic challenges. A 56-year-old female presented with headaches, vomiting, epistaxis, and cranial nerve deficits. Cerebral imaging revealed a 65-mm tumor infiltrating the sphenoid bone and adjacent structures. Subtotal resection was performed using an endoscopic nasal approach. Histopathology revealed plasmacytoma, and diagnostic workup confirmed MM. By the end of biological exploration, relapse of the sphenoid plasmacytoma was observed, and the patient was successfully treated with radiotherapy, immunochemotherapy, and autologous stem cell transplantation. After 18-month follow-up, sustained complete remission was confirmed. Although rare, the diagnosis of plasmacytoma should be considered in cases of skull base tumors. This localization is highly predictive of MM, warranting comprehensive investigations to initiate prompt and adequate management.

Successful Treatment of Extraosseous Plasmacytoma of the Oropharynx with Cervical Lymph Node Involvement

Extraosseous plasmacytoma, a rare plasma cell neoplasm, was observed in a 52-year-old male with uncommon presentation in the oropharynx with cervical lymph node involvement. The patient presented with dysphonia and left neck swelling. This case report primarily focuses on the management, resulting in a successful treatment through radiotherapy.

Impact of cytogenetic abnormalities on the risk of disease progression in solitary bone plasmacytomas

Most patients with solitary bone plasmacytomas (SBP) progress to multiple myeloma (MM) after definitive radiation therapy as their primary treatment. Whether the presence of high-risk (HR) cytogenetic abnormalities by fluorescence in situ hybridization (FISH) in the clonal plasma cells, obtained either directly from the diagnostic SBP tissue or the corresponding bone marrow examination at the time of diagnosis, is associated with a shorter time to progression (TTP) to MM is unknown. This study evaluated all patients diagnosed with SBP at the Mayo Clinic from January 2012 to July 2022. The presence of del(17p), t(14;16), t(4;14), or +1q (gain or amplification) by FISH in clonal plasma cells was defined as HR. A total of 114 patients were included in this cohort, and baseline FISH was available for 55 patients (48%), of which 22 were classified as HR (40%). The median TTP to MM for patients with SBP and HR FISH was 8 months (95% confidence interval [CI], 6.3-26) compared with 42 months (95% CI, 25-not reached [NR]) in patients with SBP without HR FISH (P < .001). In a multivariate analysis, only HR FISH was a significant predictor for shorter TTP to MM, independent of minimal marrow involvement and an abnormal serum free light chain ratio at diagnosis. Deletion (17p) and gain 1q abnormalities were the most common FISH abnormalities responsible for the short TTP to MM. Thus, assessing for HR FISH abnormalities in clonal plasma cells derived from either the diagnostic SBP tissue or the staging bone marrow examination of patients with newly diagnosed SBP is feasible and prognostic for a shorter TTP to MM.

Hypoxia-induced oxidative stress promotes therapy resistance via upregulation of heme oxygenase-1 in multiple myeloma

BACKGROUND

Multiple myeloma (MM) is a hematopoietic malignancy for which proteasome inhibitors have become available in recent years. However, many patients develop resistance to these drugs during treatment. Therefore, it is important to elucidate the mechanisms underlying resistance acquisition by proteasome inhibitors. Side population (SP) cells, which have a high drug efflux capacity and hypoxic responses in the microenvironment have both provided important insights into drug resistance in MM; however, little is known about the characteristics of SP cells in hypoxic microenvironments.

METHODS

We performed cDNA microarray analysis for SP and non-SP obtained from RPMI-8226 and KMS-11 cell lines cultured for 48 h in normoxic and hypoxic conditions (1% O₂ ). Genes specifically upregulated in hypoxic SP were examined.

RESULTS

Our comprehensive gene expression analysis identified HMOX1, BACH2, and DUX4 as protein-coding genes that are specifically highly expressed in SP cells under hypoxic conditions. We have shown that HMOX1/heme oxygenase-1 (HMOX1/HO-1) is induced by hypoxia-inducible reactive oxygen species (ROS) and reduces ROS levels. Furthermore, we found that HMOX1 contributes to hypoxia-induced resistance to proteasome inhibitors in vitro and in vivo. Excessive ROS levels synergistically enhance bortezomib sensitivity. In clinical datasets, HMOX1 had a strong and significantly positive correlation with MAFB but not MAF. Interestingly, hypoxic stimulation increased MAFB/MafB expression in myeloma cells; in addition, the knockdown of MAFB under hypoxic conditions suppressed HMOX1 expression.

CONCLUSION

These results suggest that the hypoxia-ROS-HMOX1 axis and hypoxia-induced MafB may be important mechanisms of proteasome inhibitor resistance in hypoxic microenvironments.

Development of Polyneuropathy, Organomegaly, Endocrinopathy, M Protein, and Skin Changes Syndrome after Conversion from Plasmacytoma of Bone to Multiple Myeloma

A 36-year-old man developed polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) syndrome after conversion from solitary plasmacytoma of bone to multiple myeloma. Twenty-four days following the neurological onset, he lost his independent walking ability. The level of serum vascular endothelial growth factor (VEGF) at diagnosis was 5,250 pg/mL. Three months after initiating treatment, he regained his independent walking ability in line with a reduction in the elevated serum VEGF level. Due to their genomic instability gained during conversion, myeloma cells may overproduce humoral factors and cytokines, possibly contributing to the development of neuropathy as well as the production of VEGF.

Survival trends and prognostic factors for patients with extramedullary plasmacytoma: A population-based study

Background

Extramedullary plasmacytoma (EMP) is a localized plasma cell neoplasm that originates from tissues other than bone. The survival trends and prognostic factors of patients with EMP in recent years remain unreported.

Methods

We used the SEER databases to extract the data. Survival curves were calculated using the Kaplan-Meier method and a nomogram was created based on the Cox's proportional hazards model.

Results

A total of 1676 cases of EMP were identified. Patients in period-2 (2008-2016) show similar survival (p=0.8624) to those in period-1(1975-2007). Age, gender, race, and sites were prognostic of patient outcomes. And the use of surgery was associated with improved survival. The patients were randomly assigned to the training cohort and the validation cohort in a ratio of 2:1. Four factors including age, gender, race, and sites were identified to be independently predictive of the overall survival of patients with EMP. A prognostic model (EMP prognostic index, EMP-PI) comprising these four factors was constructed. Within the training cohort, three risk groups displayed significantly different 10-year survival rates: low-risk (73.0%, [95%CI 66.9-78.2]), intermediate-risk (39.3%, [95%CI 34.3-44.3]), and high-risk (22.6%, [95%CI 15.3-30.9]) (p<0.0001). Three risk groups were confirmed in the internal validation cohort. We also constructed a 5-factor nomogram based on multivariate logistic analyses.

Conclusion

The survival of patients with EMP did not improve in recent years. The EMP-PI will facilitate the risk stratification and guide the risk-adapted therapy in patients with EMP.

Radiographic Response of Solitary Plasmacytomas After Conformal Radiotherapy May Be Delayed: Outcomes in the 3D Era

OBJECTIVE

Although recurrence rates after radiotherapy for solitary plasmacytoma (SP) are well established, little is known about how SP responds radiographically, as most historical patients were treated in the 2D era. We evaluated the response to radiotherapy among SP patients staged and treated with 3D techniques, including proton therapy, which has not yet been previously reported.

METHODS AND MATERIALS

Between 2007 and 2021, 15 SP patients (4 extramedullary, 11 bone) staged with 3D imaging and bone marrow evaluation were consecutively treated with definitive radiotherapy. The best response was categorized in 9 evaluable patients according to response evaluation criteria in solid tumors (RECIST) and positron emission tomography response criteria in solid tumors (PERCIST).

RESULTS

With a median follow-up of 34 months, 4 patients relapsed. The median time to the best response was ~2 years (26.6 mo RECIST, 25.4 mo PERCIST). Response rates differed based on response assessment criteria. PERCIST was associated with higher rates of complete (85.7%) or partial response (14.3%) compared with RECIST (16.7% complete, 33.3% partial). Two-year and 4-year PFS for extramedullary SP were 100% and 75%, compared with 91% and 55% for bone ( P =0.75). Patients treated with proton therapy (n=5) did not appear to have different patterns of relapse (1 marginal, 1 distant) compared with those treated with photons or electrons (n=10; 2 distant).

CONCLUSIONS

More conformal dose distribution with proton therapy does not appear to alter patterns of recurrence. Although response rates differ based on criteria by both RECIST and PERCIST assessments, the radiographic response may be slow and requires validation in other cohorts.

A Case Report on Solitary Extramedullary Plasmacytoma of the Pleura

Solitary plasmacytoma is an extremely rare form of plasma cell malignancy that presents as a single mass of monoclonal plasma cells located either intraosseous or extramedullary (extraosseous). Extramedullary plasmacytoma can affect any part of the body, but the most common sites of origin are the head and neck region. The involvement of pleura is very rare. Here, we are enlightening this rare presentation and making readers aware of the clinical presentation and management of this rare malignancy.

A rare case of calvarial tuberculosis from the Avar Age (8th century CE) cemetery of Kaba-Bitózug (Hajdú-Bihar county, Hungary) - Pathogenesis and differential diagnostic aspects

The aim of our paper is to present and discuss in detail the bony changes indicative of tuberculosis (TB) that were identified in a skeleton (KB67), unearthed from grave 67 of the 8th-century-CE cemetery of Kaba-Bitózug (Hungary). Furthermore, to provide the differential diagnoses of the observed alterations, with special attention to the cranial osteolytic lesions. During the macro- and micromorphological examinations of KB67, the skull revealed three small, well-circumscribed, punched-out osteolytic lesions accompanied by endocranial granular impressions, abnormal blood vessel impressions, periosteal appositions, and cortical erosion. The postcranial skeleton exhibited osteolytic lesions, cortical remodelling and erosion, and signs of hypervascularisation in the spine. Based on the differential diagnosis of the cranial osteolytic lesions and their co-occurrence with endocranial and vertebral bony changes indicative of TB, they most likely resulted from tuberculous involvement of the frontal and left parietal bones. The morphologically established diagnosis was confirmed by a PCR analysis that provided evidence for the presence of Mycobacterium tuberculosis DNA in KB67. KB67, the first reported archaeological case with calvarial TB from the present-day territory of Hungary, gives us a unique insight into the occurrence of a rare manifestation of TB in the Avar Age of the Great Plain.

Periocular Presentation of Solitary Plasmacytomas and Multiple Myeloma

AIMS

To describe patients with periocular solitary extramedullary plasmacytoma (SEMP) and multiple myeloma (MM), together with an estimate of the risk of progression from SEMP to MM.

PATIENTS AND METHODS

A retrospective case-note review for patients seen between 1978 and 2020, examining demographics, presentation, imaging, pathology, management, and outcome.

RESULTS

Twenty patients (10 male; 50%) presented at a mean age of 60.9 years, with an average symptom duration of 4.5 months. Ten (50%) patients had known systemic myeloma at ophthalmic presentation (the MM group) and, on average, they presented one decade earlier than those with occult MM discovered after orbital biopsy (p = 0.06); the majority (9/15; 60%) of patients with MM were female, whereas there was a male bias (4/5; 80%) with SEMP (p = 0.30). Most tumors (15/20; 75%) were within the anterior part of the orbit, especially superolaterally (16 patients; 80%), and the soft-tissue mass often appeared to "explode" from the frontal bone or greater wing of the sphenoid (16/20; 80%). Full treatment details were known for 19 patients: 6 (32%) had solely orbital radiotherapy, 4 (21%) chemotherapy, 6 (32%) combined chemoradiation, and 3 (16%) had combined chemoradiation with stem-cell transplant (Table 3). After an average follow up of 58 months, 1/5 (20%) patients with SEMP and 11/15 (73%) with MM had tumor-related death. The overall survival probability for all 20 patients with periocular plasmacytoma was 34% at 5 and 10 years, with MM patients having a worse outlook (27% 5-year, and 18% 10-year survival) compared with SEMP (53% survival at 5 and 10 years) (p = 0.18). None of the 5 patients with SEMP progressed to systemic MM over an average follow up of 9.1 years.

CONCLUSIONS

Although 50% patients with periocular plasmacytoma appear to have a SEMP at ophthalmic presentation, a half of these patients were found to have occult MM within 6 months of biopsy. Of those without systemic disease around the time of biopsy, none developed MM over an average follow up of more than 9 years.

A case of solitary plasmacytoma of bone showing co-expression of both immunoglobulin light chains

Background

Solitary plasmacytoma of bone (SPB) is a rare plasma cell neoplasm. It arises in bone as a single locus in the absence of any plasma cell myeloma lesions. Plasma cell neoplasms intrinsically express only one immunoglobulin light chain (IgL)—kappa or lambda—and using this fact, kappa/lambda deviation is the decisive factor for diagnosis. Co-expression of both IgLs in a single tumor cell is extremely rare.

Case presentation

We report a case of SPB that arose in the vertebra of a 52-year-old Japanese woman. Histologically, the resected mass showed diffuse plasma cell proliferation. Dual IgL expression was detected by flow cytometry, immunohistochemistry, and in situ hybridization (ISH) targeting IgL mRNA.

Conclusion

We have presented an extremely rare case of SPB showing dual expression of kappa and lambda IgLs. This unusual case of plasma cell neoplasia might represent a possible exceptional example of failure of “IgL isotypic exclusion.”

Solitary Extramedullary Plasmacytoma of the Thyroid Gland in a Patient With Subclinical Hyperthyroidism

Objective

Solitary extramedullary plasmacytoma (SEP) of the thyroid is rare, and its clinical and pathologic features are not entirely understood. Generally, patients with SEP of the thyroid also present with Hashimoto thyroiditis. We report, for the first time, a case of SEP of the thyroid in a patient with subclinical hyperthyroidism.

Methods

A 46-year-old woman presented to the emergency department with symptoms consistent with a panic attack. Following a physical examination, neck ultrasonography, and laboratory tests, we determined that the patient was hyperthyroid and possessed a toxic multinodular goiter. The patient elected to undergo a total thyroidectomy to treat the subclinical hyperthyroidism and to remove the nodules.

Results

SEP diagnosis requires consideration of the systemic spread of multiple myeloma and a combination of immunohistochemical examination, imaging, and other laboratory tests. Upon further examination, we confirmed SEP through the following criteria: the absence of kidney failure or hypercalcemia, a biopsy demonstrating plasma cell histology, a lack of bone or tissue involvement, and low serum myeloma protein concentration. The immunophenotype of the tumor cells further confirmed SEP diagnosis, with positivity for CD138, CD79a, and lambda light chain antibodies and no reactivity toward cyclin D1.

Conclusion

This case fulfilled the criteria for SEP, and we were able to rule out multiple myeloma. Currently, no standard treatment exists for SEP. Yet, the prognosis remains encouraging. Going forward, SEP of the thyroid should be considered in the differential diagnosis of a patient with subclinical hyperthyroidism and a toxic multinodular goiter.

Plasmacytoma and plasma cell myeloma affecting the jaws: A multi-institutional collaborative study

BACKGROUND

Plasma cell neoplasms are characterized by the proliferation of a single clone of plasma cells with production of a monoclonal immunoglobulin. They can manifest as a single lesion (plasmacytoma) or as multiple lesions (multiple myeloma).

METHODS

Paraffin-embedded tissue blocks of patients microscopically diagnosed with plasma cell neoplasms in the jaws were retrieved from five pathology files. Data including clinical, radiographic, microscopic and immunohistochemical findings, treatment employed and follow-up status were retrieved from the pathology reports.

RESULTS

Fifty-two cases were retrieved (mean age: 59.4 years) without sex predilection. The mandible was the most affected site (67.3%), usually associated with pain and/or paresthesia (53.8%). Lesions in other bones besides the jaws were reported for 24 patients (46.2%). Radiographically, tumours usually presented as poorly defined osteolytic lesions with unilocular or multilocular images, while microscopy revealed diffuse proliferation of neoplastic plasma cells with nuclear displacement and abundant eosinophilic cytoplasm. Two cases were classified as anaplastic, and amyloid deposits were found in two other cases. Immunohistochemistry was positive for plasma cell markers and negative for CD20 and CD3, and monoclonality for kappa light chain predominated. The overall survival rate after 5 years of follow-up was 26.6%.

CONCLUSION

Plasma cell neoplasms are aggressive tumours with a poor prognosis and involvement of the jaws may be the first complaint of the patient. Thus, oral pathologists, head and neck surgeons and dentists should be aware of their clinical, radiographic and microscopic manifestations.

Plasma cell neoplasms of the bladder: a series of 9 cases

From 2009 to 2017, we identified 9 cases of plasma cell neoplasms on biopsies of the bladder in patients without a history of plasma cell myeloma or transplantation (6 men and 3 women). Four of the nine showed amyloid deposition, of which one additionally revealed a clear cell adenocarcinoma of the bladder. Follow-up was obtained in 7 cases. Of 3 cases (including 2 with amyloid) for which electrophoresis and immunofixation results were obtained, the 2 amyloid cases showed evidence of serum or urine paraproteins: serum IgM kappa in a patient with kappa light chain-restricted plasma cell neoplasm and urine IgA lambda in a patient with lambda light chain-restricted plasma cell neoplasm. By way of contrast, 1 case with kappa light chain-restricted plasma cell neoplasm in the absence of amyloid showed no serum monoclonal protein. Bone marrow biopsy results were obtained in the 2 amyloid cases revealing a population of 5% or less plasma cells with no assessment of clonality and, thus, were not diagnostic of plasma cell myeloma. In congruence, the 2 amyloid cases also showed no radiologic evidence of systemic plasma cell myeloma. One patient with plasma cell neoplasm only received chemotherapy and radiation without subsequent biopsies; one patient with plasma cell neoplasm, amyloid, and clear cell adenocarcinoma received radiation with an absence of neoplastic disease on subsequent biopsies. In addition, no evidence of systemic amyloid was found in the cases with bladder amyloidosis. Plasma cell neoplasms of the bladder, with and without amyloid deposition, are rare; this is the first known case series. In 7 cases with follow-up, plasma cell myeloma did not appear to manifest in a 1- to 127-month follow-up. However, paraproteins were identified on further testing in 2 cases with amyloid. Although bladder plasma cell neoplasms with and without amyloid tend to have a favorable prognosis in short-term follow-up, our study supports the need for additional workup for systemic disease, particularly in those with concurrent amyloidosis.

Radiotherapy for the treatment of solitary plasmacytoma: 7-year outcomes by a mono-institutional experience

OBJECTIVES

Solitary plasmacytoma (SP) is characterized by a single mass of clonal plasma cells. Definitive RT can result in long-term local control of the SP. Due to the small number of patients and narrow range of doses, phase III randomized trials are lacking. The aim of this study is to further support the potential use of RT for the treatment of SP.

METHODS

Clinical data of all patients treated for SP at our Institution between 1992 and 2018 were reviewed. A total of 42 consecutive patients were analyzed.

RESULTS

The median follow-up was 84.8 months. Radiation dose did not differ significantly as a function of sex, type of SP (solitary bone plasmacytoma or as extramedullary plasmacytoma), tumor size; conversely differs significantly as a function of age (p = 0.04). The 5y-OS and 10y-OS were, respectively, 96 and 91%. Local recurrences developed in 21.4% of patients (9/42). 16 patients progressed to MM (38.1%). The 5y-progression to MM free survival (PMFS) and the 10y-PMFS were, respectively, 68.6 and 61.9%.

CONCLUSIONS

Our data confirm that good results are achievable with RT to treat SP, but they don't allow defining a dose-effect correlation; therefore, it remains uncertain which is the most effective dose and whether lower doses can guarantee adequate disease control.

Clinical presentation and outcomes of solitary plasmacytoma in a tertiary hospital in the UK

Solitary plasmacytoma is a rare localised neoplasm of monoclonal plasma cells. The standard treatment involves radical radiotherapy; however, a significant proportion of patients subsequently develop multiple myeloma. In this study, we evaluate the outcomes of solitary plasmacytoma in a retrospective cohort of patients treated in a single tertiary centre.The case records of plasmacytoma patients treated in a 15-year period were analysed and retrospectively followed up from the date of diagnosis. Thirty-four cases met the inclusion criteria; 27 (79%) solitary plasmacytoma of bone (SBP) and 7 (21%) extramedullary plasmacytoma (EMP). The thoracic vertebrae were the commonest sites for SBP while EMP occurred most frequently in the upper airway. Pain and spinal cord compression were the most frequent symptoms. A paraprotein was detectable in 18 (53%) patients. Over a median follow-up of 48 months, 13 (38%) developed multiple myeloma. The 5- and 10-year survival rates were 80% and 56%, respectively; median progression-free survival was 77 months. Four patients (12%) developed a second malignancy.Progression to multiple myeloma remains a formidable challenge in the management of solitary plasmacytoma, hence adjunct therapies are needed.

Extramedullary Plasmacytoma: Long-Term Clinical Outcomes in a Single-Center in China and Literature Review

The aim is to analyze the clinical outcomes of patients with extramedullary plasmacytoma (EMP) and review the characteristics of this disease. We retrospectively reviewed the clinical data of a cohort of 22 patients diagnosed with EMP between 1983 and 2017. Baseline characteristics and progression data were collected to calculate the incidence of progression to multiple myeloma (MM) and to analyze survival rates and outcomes. Previous major cohort studies were reviewed and compared with this study. Extramedullary plasmacytomas were located in the head and neck in 17 (77%) of the 22 patients. The median time between onset and diagnosis was 7 months, and the median age at diagnosis was 52.5 years (range 15-72 years). Extramedullary plasmacytoma occurred more frequently in men with an approximate ratio of 2.1:1. The majority of patients underwent surgery (13/22, 59.1%) and half received radiation (11/22, 50%). A small proportion of patients received chemotherapy (2/22, 9.1%). There was a median follow-up time of 98.5 months. The 5-year overall survival, progression-free survival, and MM-free survival rates were 84.2%, 67.3% and 75.9%, respectively. Complete resection without major functional damage is a promising option that can favorably improve prognosis in patients with resectable disease. Patients with regional lymph node metastasis or positive immunoelectrophoresis results require more aggressive treatment and may have poorer prognosis.

Retrospective analysis of plasmacytoma in Kansai Myeloma Forum Registry

We retrospectively analyzed 51 patients with solitary plasmacytoma diagnosed from October 2002 to September 2018 from a cohort of 3575 patients with plasma cell dyscrasias registered in the Kansai Myeloma Forum. Twenty-seven patients had solitary bone plasmacytoma (SBP) and 24 had extramedullary plasmacytoma (EMP), with prevalence of 0.8% and 0.7%, respectively. The most frequent M protein was IgG (40%) in SBP, whereas non-secretory proteins were most frequent (50%) in EMP. Five-year overall survival was 78.2% in SBP and 80.8% in EMP (P = 0.894). Among patients with SBP, 44% progressed to MM with a median time of 10.5 months (2.4-93.3 months), whereas 8% of EMP patients progressed to MM with a median time of 18.6 months (13.0-24.2 months). The most frequent treatment was radiotherapy (41%) or observation (41%) in SBP, and chemotherapy (54%) in EMP. No statistically significant difference was observed upon univariate analysis of prognostic factors including age, sex, performance status, and IgG M protein. Our results suggest that there are biological differences between SBP and EMP in real-world settings.

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.

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.

Does Radiotherapy with Surgery Improve Survival and Decrease Progression to Multiple Myeloma in Patients with Solitary Plasmacytoma of Bone of the Spine?

OBJECTIVE

To investigate the outcomes of radiotherapy with or without surgery during treatment of patients with solitary plasmacytoma of bone (SBP) of the spine.

METHODS

Patients diagnosed with SBP of the spine treated with radiotherapy with or without surgery were identified and extracted from the SEER database. Propensity score matched (PSM) analysis was performed to balance patient characteristics between radiotherapy alone and radiotherapy with surgery groups. Patients in different age-groups were stratified and analyzed.

RESULTS

A total of 1275 patients with SBP of the spine treated with radiotherapy with or without surgery were extracted from the SEER database. Before PSM, the unadjusted Kaplan-Meier curve showed that the radiotherapy with surgery group had worse overall survival than did the radiotherapy without surgery group (both P < 0.05), whereas the difference of overall survival was attenuated after PSM. Stratified analysis found that the radiotherapy with surgery group had less progression to multiple myeloma for young patients (age <45 years) with SBP of the spine than did the radiotherapy without surgery group.

CONCLUSIONS

The results of our study suggest that radiotherapy with surgery may show less progression to multiple myeloma for younger patients with SBP of the spine.

Solitary Plasmacytoma Treated by Lenalidomide-Dexamethasone in Combination with Radiation Therapy: Clinical Outcomes

PURPOSE

The study evaluates the results of the concurrent use of lenalidomide-dexamethasone with intensity modulated radiation therapy (IMRT) for solitary plasmacytoma in terms of toxicity and outcome.

METHODS AND MATERIALS

Forty-six patients were treated for histologically proven solitary plasmacytoma (SP) between June 2007 and June 2018 in our Department (Curie Institute, Paris, France). All patients received IMRT. The median total dose was 40 Gy (range, 40-46). Prescription of concurrent lenalidomide-dexamethasone with radiation therapy was left to the discretion of the referring hematologist-oncologist and started the first day of radiation therapy for 4 cycles.

RESULTS

Twenty-seven solitary plasmacytoma were treated with IMRT alone and 19 with lenalidomide-dexamethasone in association with IMRT. At 5 years, the local control, multiple myeloma-free survival (MMFS), and progression-free survival (PFS) rates were 96.3%, 85.4%, and 60%. MMFS and PFS were significantly higher in the IMRT plus lenalidomide-dexamethasone group compared with IMRT alone group (100% vs 77.1%, P = .02 and 81.7% vs 48.4%, P = .047, respectively). No major toxicity was found in either group.

CONCLUSIONS

Lenalidomide-dexamethasone in association with IMRT in the treatment of solitary plasmacytoma is safe and improves MMFS and PFS. Further prospective and comparative studies are needed to confirm these results.

Bone Pathology for Hematopathologists

Bone pathology can be challenging because the skeleton is a living tissue prone to developing a diverse array of inflammatory, metabolic, genetic, reactive, circulatory, and neoplastic abnormalities. Several areas of bone pathology are particularly difficult or problematic for hematopathologists given the close resemblance of some hematologic entities to primary/metastatic bone lesions; examples include plasmacytic disorders versus osteoblastic tumors and lymphoma/leukemia versus round cell tumors of bone. This article provides a conceptual and practical overview of selective bone disorders commonly encountered in the differential diagnosis of hematologic diseases.

Long-term clinical outcomes in a cohort of patients with solitary plasmacytoma treated in the modern era

BACKGROUND

The risk of recurrence of solitary plasmacytoma (SP)/progression to MM is well established, but patient, imaging and treatment factors influencing risk of progression require further evaluation.

METHODS

This is a retrospective analysis of 66 SP patients (23 UK, 43 Brazil) diagnosed 1989-2016. Patient baseline characteristics were recorded. The incidence of progression to MM was calculated, including biochemical and imaging findings and the treatment modality received. Survival estimates were determined by Kaplan-Meier analyses.

RESULTS

With a median follow-up of 53.6 months the 5 year overall survival (OS) was 90.7% (95%CI 79-96%). The median progression free survival (PFS) from diagnosis was 61 months. Cumulative incidence of progression to MM was 49.9% at 5 years (95% CI 35.6-62.6%) and was significantly higher with bone plasmacytoma (47.2%, 95%CI 31.9-61.1%), than an extramedullary location (8.3%, 95%CI 0.4-32.3%, Gray test p = 0.0095)). The majority of patients with solitary bony plasmacytoma (SBP) received radiotherapy (RT) (51/53, 96.2%) whereas most extramedullary cases were treated with surgical resection (7/13, 53.8%). A small proportion of SBP patients received additional upfront chemotherapy, with 5/6 in remission after a median follow-up (FU) of 10 years. The diagnostic yield of surveillance functional FU imaging without other indications of relapse/progression was low. The positive predictive value of functional FU imaging was high but with a low negative predictive value, especially in cases of suspected relapse/progression.

CONCLUSION

Our data suggests functional imaging should be used if clinical suspicion of relapse/progression, rather than a routine surveillance tool, and upfront adjuvant chemotherapy is worthy of prospective evaluation.

Impact of prior diagnosis of monoclonal gammopathy on outcomes in newly diagnosed multiple myeloma

Multiple myeloma (MM) is consistently preceded by monoclonal gammopathy of undetermined significance (MGUS), smoldering myeloma (SMM), or solitary plasmacytoma (SPC). There is a lack of data regarding impact of these pre-existing monoclonal gammopathies (MGs) on MM outcomes. Patients with prior diagnosis of MGUS, SMM, or PC from 1973 to 2015 (cases) were identified from our institution's database and compared to those without a known MG (controls). The primary outcome of interest was overall survival (OS). Multivariate analysis was performed to ascertain factors impacting all-cause mortality. We identified 774 patients with a prior diagnosis of MGUS, SMM or SPC (cases) and a control population (1:2) matched for the year of diagnosis (n = 1548). After a median follow-up of 81 months, the cases showed a longer median OS than the controls (71 months vs. 56 months). The improved OS was limited to those with a known prior diagnosis of SMM (80 months) and SPC (95 months), compared to MGUS (60 months). Multivariable analysis revealed that MM patients with known prior MG had less overall mortality than those without, and this was limited to prior SMM/SPC group (HR 0.68, 95% CI: 0.50-0.93), as compared to the MGUS group (HR 0.83, 95% CI: 0.66-1.05).

Solitary Plasmacytoma of Bone of the Spine: Results From Surveillance, Epidemiology, and End Results (SEER) Registry

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

To determine the prognostic indicators in patients with solitary plasmacytoma of bone (SPB) of the spine.

SUMMARY OF BACKGROUND DATA

Population-level estimates for prognosis among patients with SPB of the spine are still lacking. Sociodemographic and clinical predictors of outcome have not been well characterized.

METHODS

The Surveillance, Epidemiology, and End Results Registry was used to identify all patients with SPB of the spine from 1995 through 2014. Associated population data were used to determine annual incidence and limited-duration prevalence. Overall survival (OS) estimates were obtained using the Kaplan-Meier method and compared across groups using log-rank test. A Cox regression model was used for multivariate analysis of survival. Logistic regression was performed to identify predictors of the progression to multiple myeloma (MM).

RESULTS

The incidence and prevalence of the disease increased during the study period. Spinal SPB most commonly affected older people (>50) with a male preponderance. The median OS were 74.0 months. The 5 and 10-year survival rates for these patients were 56.1% and 36.7%, respectively. On multivariable analyses, older age, and surgery without radiotherapy were correlated with poor survival of patients with spinal SPB. The 3-year probability of progression to MM was 10.1%. Patients aged >70 years were associated with progression to MM. There was no significant association between the methods of surgical resection (radical or local/partial) and OS or progression to MM.

CONCLUSION

The findings of this study provide population-based estimates of the incidence, prevalence and prognosis for patients with SPB of the spine. This analysis indicated that the only identifiable prognostic indicators were older age and surgery without radiotherapy. Moreover, the methods of surgical resection did not influence the OS or progression to MM.

LEVEL OF EVIDENCE

4.

How We Manage Patients with Plasmacytomas

PURPOSE OF REVIEW

To discuss the diagnostic approach, treatment options, and future considerations in the management of plasmacytomas, either solitary or in the context of overt multiple myeloma (MM).

RECENT FINDINGS

Advanced imaging techniques such as whole-body magnetic resonance imaging and positron emission tomography/computerized tomography are essential for the diagnostic workup of solitary plasmacytomas (SP) to rule out the presence of other disease foci. The role of flow cytometry and clonal plasma cell detection is currently under study together with other prognostic factors for the identification of patients with SP at high risk of progression to overt MM. Solitary plasmacytomas are treated effectively with local radiotherapy whereas systemic therapy is required at relapse. Clonal plasma cells that accumulate at extramedullary sites have distinct biological characteristics. Patients with MM and soft tissue involvement have poor outcomes and should be treated as ultra-high risk. A revised definition of SP that distinguishes between true solitary clonal PC accumulations and SP with minimal bone marrow involvement should be considered to guide an appropriate therapeutic and follow-up approach. Future studies should be conducted to determine optimum treatment approaches for patients with MM and paraskeletal or extramedullary disease.

The role of initial 18F-FDG PET/CT in the management of patients with suspected extramedullary plasmocytoma

Background

Extramedullary plasmacytoma (EMP) is a plasma cell malignancy that originates in soft tissues without evidence of systemic spread, and its management differs from other plasma cell neoplasms. The purpose of the present study was to evaluate the role of initial ¹⁸F-FDG PET/CT in the management of patients with clinical suspected EMP.

Methods

¹⁸F-FDG PET/CT scans performed in 21 patients (M/F = 12/9, mean age 51.1 ± 15.3 years) with clear suspicion of EMP from 2006 to 2015 were analysed retrospectively. The detection of new lesions and the change in treatment were evaluated.

Results

PET/CT detected new lesions in 38.1% (8/21) of patients with 17 lesions, and lymph nodes were the most common site, accounting for 70.6% (12/17) of all lesions, followed by bone (n = 2), and less frequently, breast (n = 1), lung (n = 1), and stomach (n = 1). These findings resulted in treatment changes in 7 patients with EMP. Among these, 4 patients had major treatment changes and 3 patients had minor changes. Of the 21 patients, progression to MM was observed in 8 patients (8/21, 38.1%). In univariate analysis, tumour size > 4 cm and partial response (PR) after treatment were significant prognostic factors for Progression-free survival (PFS).

Conclusions

Our data indicated that ¹⁸F-FDG PET/CT is helpful in the detection of additional lesions throughout the body, including lymph node involvement and distant additional lesion, which may have resulted in treatment change.

Gastrointestinal manifestations of extramedullary plasmacytoma: a narrative review and illustrative case reports

Introduction Solitary extramedullary plasmacytoma are rare, solid-mass tumours which appear immunophenotypically similar to multiple myeloma. The diagnosis and management of gastrointestinal plasmacytoma is complex and requires multidisciplinary input. This study presents a narrative review of intra-abdominal extramedullary plasmacytoma, illustrated with two case studies. Methods The PubMed database was searched without date restrictions for reports of intra-abdominal extramedullary plasmacytoma to synthesise a narrative review. Electronic records were reviewed at a high-volume, quaternary soft-tissue sarcoma centre to identify patients with histopathologically confirmed extramedullary plasmacytoma affecting the gastrointestinal tract. Results Gastrointestinal extramedullary plasmacytomas can present with mass effect or organ-specific dysfunction. Techniques for tissue diagnosis of extramedullary plasmacytoma vary dependent on location, with a formal diagnosis often being made from a resected specimen. Management can include surgery, radiotherapy, systemic chemotherapy or a combination. No high-quality evidence base exists to guide treatment. Two case studies of operated gastrointestinal extramedullary plasmacytoma are presented at different phases of disease progression, with a resultant impact on survival. Conclusion Intra-abdominal extramedullary plasmacytoma is a rare and heterogeneous condition that lacks consensus guidelines for diagnosis and management. Collaboration between international specialist centres will create better quality evidence for treatment of this cohort.

[Applications of one-stage total spondylectomy by anterior and posterior approaches for solitary plasmacytoma of cervical spine]

Objective

To investigate the feasibility of one-stage total spondylectomy by anterior and posterior approaches for treating solitary plasmacytoma (SP) of cervical spine.

Methods

Between June 2000 and March 2015, the clinical data, diagnosis, and treatment of 12 patients with SP of cervical spine were retrospectively analyzed. There were 8 males and 4 females, with a mean age of 46 years (range, 28-74 years). The mean disease duration was 8.4 months (range, 3-15 months). There were 2 cases in C ₂ segment, 4 cases in C ₃, 2 cases in C ₄, 1 recurrent case in C ₅, C ₆, and 3 cases in C ₇. According to WBB (Weinstein-Boriani-Biagini) surgical staging system, the tumor mainly occupied the vertebral body areas and expanded outside to 4 or 9 radiating zone in 8 cases, expanded both outsides to 4 or 9 radiating zones in 4 cases; 7 cases of them affected A to D layers, other 5 cases affected B to D layers. Preoperative Frankel system showed grade B in 1 case, grade C in 6 cases, and grade D in 5 cases. One vertebra segment was involved in 11 cases, and 2 vertebra segments were involved in 1 case. The unilateral vertebral artery was involved in 4 cases and bilateral vertebral artery in 1 case. One-stage total spondylectomy by anterior and posterior approaches for SP of cervical spine was applied in all patients, which all received adjuvant radiotherapy postoperatively. The operation time, intraoperative blood loss, complications, Frankel system, and visual analogue scale (VAS) score were recorded and analyzed.

Results

The operation time was 6.8-9.3 hours (mean, 7.2 hours), and the intraoperative blood loss was 1 100-2 600 mL (mean, 1 600 mL). Esophageal leakage occurred in 1 patient with C ₅, C ₆ recurrent SP at 1 week after operation and 1 case presented with fat liquefaction of wound, who were cured by symptomatic treatment. Other patients showed no neurological deficit, major vascular injury (especially vertebral artery), phrenic nerve injury, superior laryngeal nerve injury, laryngeal nerve injury, respiratory failure, or other complications. All the 12 patients were followed up 27-98 months (mean, 58 months). The symptoms of spinal cord compression disappeared or improved after operation. At last follow-up, the nerve function was recovered to Frankel grade E in all patients; the VAS score decrease to 1.1±0.7, showing significant difference when compared with preoperative value (6.7±2.7) ( t=2.485, P=0.014). Two patients had local recurrence at 29 months and 37 months after operation respectively, which were treated with adjuvant chemotherapy. One of them finally progressed to multiple myeloma and died of multiple organ failure after 43 months, the other one survived with residual tumor. One case presented with internal fixator loosening and breaking at 4 years after operation, who was performed revision surgery. The other patients had no tumor recurrence or malignant change during the follow-up, no complication such as internal fixator loosening or breaking occurred.

Conclusion

For patients with SP of cervical spine, surgical intervention is an acceptable treatment option. One-stage total spondylectomy by anterior and posterior approaches can decline the local recurrence and relieve the symptoms of spinal cord compression, so as to improve patients' life quality. However, patients with progression to multiple myeloma should be treated with individualized therapeutic regimen, and the prognosis may be poor.

Diagnosis, treatment, and response assessment in solitary plasmacytoma: updated recommendations from a European Expert Panel

Solitary plasmacytoma is an infrequent form of plasma cell dyscrasia that presents as a single mass of monoclonal plasma cells, located either extramedullary or intraosseous. In some patients, a bone marrow aspiration can detect a low monoclonal plasma cell infiltration which indicates a high risk of early progression to an overt myeloma disease. Before treatment initiation, whole body positron emission tomography-computed tomography or magnetic resonance imaging should be performed to exclude the presence of additional malignant lesions. For decades, treatment has been based on high-dose radiation, but studies exploring the potential benefit of systemic therapies for high-risk patients are urgently needed. In this review, a panel of expert European hematologists updates the recommendations on the diagnosis and management of patients with solitary plasmacytoma.

Solitary Plasmacytoma

Solitary plasmacytoma is a rare disease characterized by a localized proliferation of neoplastic monoclonal plasma cells, without evidence of systemic disease. It can be subdivided into solitary bone plasmacytoma if the lesion originates in bone, or solitary extramedullary plasmacytoma if the lesion involves a soft tissue. The incidence of solitary bone plasmacytoma is higher than solitary extramedullary plasmacytoma. Also, the prognosis is different: even if both forms respond well to treatment, overall survival and progression-free survival of solitary bone plasmacytoma are poorer than solitary extramedullary plasmacytoma due to its higher rate of evolution in multiple myeloma. However, the recent advances in the diagnosis of multiple myeloma can better refine also the diagnosis of plasmacytoma. Flow cytometry studies and molecular analysis may reveal clonal plasma cells in the bone marrow; magnetic resonance imaging or 18 Fluorodeoxyglucose positron emission tomography could better define osteolytic bone lesions. A more explicit exclusion of possible occult systemic involvement can avoid cases of misdiagnosed multiple myeloma patients, which were previously considered solitary plasmacytoma and less treated, with an unavoidable poor prognosis.

Due to the rarity of the disease, there is no uniform consensus about prognostic factors and treatment. Radiotherapy is the treatment of choice; however, some authors debate about the radiotherapy dose and the relationship with the response rate. Moreover, the role of surgery and chemotherapy is still under debate. Nevertheless, we must consider that the majority of studies include a small number of patients and analyze the efficacy of conventional chemotherapy; few cases are reported concerning the efficacy of novel agents.

11C-Methionine-PET in Multiple Myeloma: A Combined Study from Two Different Institutions

¹¹C-methionine (MET) has recently emerged as an accurate marker of tumor burden and disease activity in patients with multiple myeloma (MM). This dual-center study aimed at further corroboration of the superiority of MET as positron emission tomography (PET) tracer for staging and re-staging MM, as compared to ¹⁸F-2`-deoxy-2`-fluoro-D-glucose (FDG).

78 patients with a history of solitary plasmacytoma (n=4), smoldering MM (SMM, n=5), and symptomatic MM (n=69) underwent both MET- and FDG-PET/computed tomography (CT) at the University Centers of Würzburg, Germany and Navarra, Spain. Scans were compared on a patient and on a lesion basis. Inter-reader agreement was also evaluated. In 2 patients, tumor biopsies for verification of discordant imaging results were available.

MET-PET detected focal lesions (FL) in 59/78 subjects (75.6%), whereas FDG-PET/CT showed lesions in only 47 patients (60.3%; p<0.01), accordingly disease activity would have been missed in 12 patients. Directed biopsies of discordant results confirmed MET-PET/CT results in both cases.

MET depicted more FL in 44 patients (56.4%; p<0.01), whereas in two patients (2/78), FDG proved superior. In the remainder (41.0%, 32/78), both tracers yielded comparable results. Inter-reader agreement for MET was higher than for FDG (κ = 0.82 vs κ = 0.72).

This study demonstrates higher sensitivity of MET in comparison to standard FDG to detect intra- and extramedullary MM including histologic evidence of FDG-negative, viable disease exclusively detectable by MET-PET/CT. MET holds the potential to replace FDG as functional imaging standard for staging and re-staging of MM.

Solitary Plasmacytoma of the Mesentery: A Systematic Clinician's Diagnosis

INTRODUCTION

Plasmacytoma is an uncommon plasma cell neoplasm and its localized form is solitary plasmacytoma of the bone and solitary extramedullary plasmacytoma. Solitary plasmacytoma of the mesentery is extremely rare, reported only in a handful of cases.

CASE PRESENTATION

A 47-year-old man with nonspecific abdominal complains was found to have an ill-defined mass on his mesenteric root. Laparoscopic biopsy and stepwise histopathological examination revealed a mesenteric plasmacytoma, and extensive imaging and laboratory investigations led to the diagnosis of the solitary mesenteric plasmacytoma. The patient underwent definitive radiotherapy and remains under remission one year later.

DISCUSSION

Plasma cell dyscrasias include a variant of proliferative disease, characterized by clonal expansion of bone marrow plasma cells, producing a massive quantity of monoclonal immunoglobulin called paraprotein or M-protein. Solitary extramedullary plasmacytoma accounts for only 3-5% of all plasma cell neoplasms. Meticulous adherence to the established diagnostic criteria helps the clinician to set the correct, yet very unusual and unexpected diagnosis.