Case report
Ukrainian Neurosurgical Journal. 2026;32(2):112-118
https://doi.org/10.25305/unj.349396
1 Internal Medicine №1 Department, Poltava State Medical University, Poltava, Ukraine
2 Hematology Department, Communal Enterprice “Poltava Regional Clinical Hospital n.a. M.V. Sklifosovsky Poltava Regional Council”, Poltava, Ukraine
3 Neurosurgery Department, Communal Enterprice “Poltava Regional Clinical Hospital n.a. M.V. Sklifosovsky Poltava Regional Council”, Poltava, Ukraine
Received: 05 January 2026
Accepted: 09 February 2026
Address for correspondence:
Tetiana V. Lymanets, Internal Medicine №1 Department, Poltava State Medical University, 23, Shevchenko Str., Poltava, 36011, Ukraine, email: t.lymanets@pdmu.edu.ua
Two presented case reports that highlight extramedullary spinal cord plasmacytomas in patients with diagnosed multiple myeloma are intended to change the paradigm of understanding the indication of surgical intervention. In the first case, the condition manifested as a relapse of kappa light chain multiple myeloma, whereas in the second case, it emerged as a primary manifestation of the same disease. Both patients received a combination chemotherapy of bortezomib, lenalidomide, and dexamethasone, which proved to be highly effective, eliminating the need for surgical intervention.
Keywords: multiple myeloma; spinal cord plasmacytoma; soft tissue extramedullary disease; chemotherapy
Introduction
Multiple myeloma (MM) is a malignant plasma cell disorder characterized by bone marrow infiltration and the production of monoclonal proteins. MM accounts for approximately 1% of all malignant neoplasms and about 15% of all hematologic malignancies [1, 2]. Clinically, it commonly manifests with anemia, hypercalcemia, renal dysfunction, osteolytic bone destruction, and immunodeficiency predisposing to recurrent infections [2‒4]. In some patients, plasma cells acquire the ability to proliferate outside the bone marrow, leading to the development of extramedullary plasmacytomas (EMP). Spinal involvement may result in compression of the spinal cord or nerve roots, causing pain and neurological deficits [5]. Patients experiencing relapsed MM after several chemotherapy (CT) treatment lines face limited specific options with low chances for complete remission. The relapse also raises the likelihood of secondary infiltration into organs and systems due to soft tissue tumors spread [6, 7]. However, EMP could be a primary presentation of MM, which requires thorough diagnostic evaluation. Management of such cases requires a multidisciplinary approach, combining systemic therapy, surgery and radiotherapy [5].
Two case reports of extramedullary spinal cord plasmacytomas are presented: the first manifesting as a relapse of kappa light chain MM, and the second as a primary presentation of the disease type. Both patients received combined CT with bortezomib, lenalidomide and dexamethasone, which showed high effectiveness without surgical intervention.
Case report 1. This clinical case presents the results of patient’s management with relapsed MM, which clinically manifested by spinal cord compression on the background vertebral plasmacytoma development at the level of Th5-Th7 [6].
The patient was a 49-year-old female diagnosed with stage III A (Durie-Salmon) kappa light-chain MM featuring extensive bone lesions including skull abnormalities and wedge-shaped vertebrae deformities at levels C6 and Th3-9 along with acute spinal cord compression leading to ischemic myeloneuropathy and sensory syndromes.
In August 2020 she was admitted to the Hematology Department of CE "Poltava Regional Clinical Hospital named after M.V. Sklifosovsky PRC" presenting with significant sensory loss in her lower limbs accompanied by paresthesia and gait disturbances as well as loss of bladder control. The above symptoms had developed gradually over two weeks.
According to anamnesis, the patient was diagnosed with MM in September 2012 following a myelogram indicating that plasma cells constituted approximately 44%. Over time she received three lines of chemotherapy: VAD (vincristine-doxorubicin-dexamethasone) in 2012, achieving partial response; TCD (thalidomide-cyclophosphamide-dexamethasone) in 2015 followed by another TCD regimen in 2018 with thalidomide maintenance therapy until December 2019.
The progression of MM was noted in August 2020. Clinically, MM relapse was associated with worsening neurological symptoms and pelvic dysfunction. No back pain was noticed. Serum analysis showed free kappa light chains elevated at 344 mg/L (normal value up to 19.4 mg/L). MRI scan revealed an intradural extramedullary plasmacytoma compressing the spinal cord between Th5-Th7 (Fig. 1). Spinal stability was assessed according to Spine Instability Neoplastic Score (SINS) as potentially unstable (totally 11 points). The neurosurgeon recommended surgical intervention with spinal cord decompression in case of no response to systemic chemotherapy after treatment initiation.
Fig. 1. MRI images of the first presented patient in August 2020 at the time of third relapse
To treat this third relapse, the patient commenced her fourth-line chemotherapy using VRD regimen (bortezomib 1.3 mg/m2 1, 4, 8, 11 days, lenalidomide 25 mg per day 1-14 days, dexamethasone 20 mg/day 1, 2, 4, 5, 8, 9, 11, 12 days). This resulted in significant clinical improvement, post-treatment restoring sensation in lower extremities along with pelvic control functions after three cycles, which allowed to avoid surgical intervention in this case.
By April 2021, after completing eight cycles under VRD regimen a very good partial response was achieved per International Myeloma Working Group (IMWG) criteria, showing free kappa light chains reduced to 33.8 mg/L – a decrease by 90%. Subsequent MRI indicated substantial reduction in size regarding extramedullary neoplasm located around Th6, alongside changes consistent with previous spinal injury caused by plasmacytoma compression (Fig. 2). After completing the VRD in April 2021, the patient was followed by lenalidomide maintenance for two years.
Fig. 2. MRI control images of the first presented patient in April 2021 after 8 cycles of VRD chemotherapy
Case report 2. This report presents a case of primary diagnosed MM with a plasmacytoma of the lumbar spine treated with VRD chemotherapy regimen as a first-line therapy and monitored by magnetic resonance imaging (MRI).
In February 2025, a 69-year-old male patient presented with progressive lumbar pain without preceding trauma which intensified with movement and changes in body position, radiated to both lower limbs. The pain was continuous, significantly limiting mobility and showed minimal response to treatment with nonsteroidal anti-inflammatory drugs. MRI of the lumbosacral spine (Fig. 3) performed on February 13, 2025, revealed spinal canal stenosis at the L3–L4 level, secondary lytic lesions involving Th11, Th12, and L3, pathological fractures of Th12 and L3 and deformities of the L1 and L4 vertebral bodies. A pathological MRI signal alteration was observed in the dorsal portion of the L3 vertebral body, appearing hypointense on T1-weighted images, hyperintense on T2 TIRM sequences and isointense on standard T2-weighted sequences. The lesion occupied approximately half of the vertebral body and extended to the vertebral arch, both left articular processes, the inferior right articular process, and the spinous process. Signs of central spinal canal stenosis at the L3–L4 segment were also present.
Fig. 3. MRI images of the second patient obtained in February 2025 at the time of initial clinical picture developed
The patient received symptomatic pain relief therapy with minimal response. On June 2, 2025, the patient was evaluated by a neurosurgeon, who suspected spinal plasmacytoma and recommended a consultation with hematologist. Sternal bone marrow aspiration performed on June 3, 2025, demonstrated bone marrow infiltration by plasma cell lineage elements (plasmacytes – 35.5%, proplasmacytes – 4.5%, plasmablasts – 1.0%). Serum protein electrophoresis and immunofixation performed on June 10, 2025, revealed no monoclonal paraproteins, whereas urine electrophoresis detected Bence–Jones protein of the kappa type (0.216 g/L in the gamma zone). The β2-microglobulin level was elevated to 3.65 mg/L.
Skeletal radiography performed on June 10, 2025, demonstrated multiple poorly demarcated lytic foci in the skull (1–3 mm in diameter), bilateral humeral bone lesions (up to 0.5 cm, predominantly on the right), and bilateral femoral bone lesions (up to 0.8 cm, predominantly on the right).
Based on the clinical, radiological and laboratory findings, the diagnosis of kappa light-chain MM, stage II according to the International Staging System (ISS), was established.
The patient was admitted to the Hematology Department of CE "Poltava Regional Clinical Hospital named after M.V. Sklifosovsky PRC". In June 2025, first-line chemotherapy according to the VRD regimen along with zoledronic acid was initiated. The neurosurgeon assessed spinal stability by the SINS score with 12 points as potentially unstable and the decision for surgical intervention was recommended to be postponed after completing the first course of VRD treatment. In July 2025, clinical improvement was achieved and pain was significantly released. Upon repeated neurosurgical consultation, the SINS score showed 10 points the decision was made to avoid spinal surgery and continue chemotherapy.
After six cycles of chemotherapy, the serum and urine M-spikes were no longer detectable: the complete response was achieved according to the criteria of the International Myeloma Working Group (IMWG). Follow-up MRI (Fig. 4), performed on December 27, 2025, revealed a visible reduction of the lesion at the L3 vertebral level and improvement of spinal canal stenosis, classified as Lee grade 3 at the L3–L4 segment. Clinically, the patient reported pain reduction, improved mobility and gradual recovery of daily activity tolerance. Considering the clinical improvement of symptoms and the visual reduction on MRI, continuation of chemotherapy according to the VRD regimen was recommended up to eight cycles followed by maintenance therapy with lenalidomide.
Fig. 4. MRI control images of the second patient obtained in December 2025 after 6 VRD cycles of chemotherapy
Discussion
MM is a malignancy of plasma cells characterized by bone marrow infiltration and the production of monoclonal proteins, and sometimes it manifests with neurological symptoms due to spinal cord compression by extramedullary plasmacytoma growth. According to the recommendations of a European Expert Panel, all patients with suspected solitary plasmacytoma should undergo bone marrow aspiration and biopsy to evaluate plasma cell morphology and the extent of marrow infiltration. Given the diagnostic and prognostic significance, the degree of clonal plasma cell infiltration should be assessed by flow cytometry, kappa/lambda light chain labeling on bone marrow aspirates or immunohistochemistry on biopsy samples and by the presence of numerous cytogenetic aberrations of the tumor cells [8, 9].
Soft-tissue involvement in MM has been recognized since the earliest descriptions of the disease. Historical autopsy reports demonstrated extra-skeletal infiltration in approximately 70% of patients with MM [1]. Soft-tissue plasmacytomas indicate a more aggressive phenotype of MM, reflecting the capacity of malignant plasma cell clones to proliferate and survive outside the bone marrow microenvironment. Extramedullary involvement in MM correlates with low responsiveness to therapy, rapid disease progression, and markedly reduced overall survival [10-14]. Data on the incidence of EMP remain limited. According to published studies, EMP is detected in approximately 7–17% of MM patients at diagnosis and in 6–20% during the disease course with variability largely depending on study design and diagnostic methods [11, 13]. Soft-tissue plasmacytomas may arise through three principal mechanisms: direct extension from skeletal lesions following cortical bone disruption; hematogenous dissemination resulting in infiltration of distant organs or soft tissues without bone involvement; in rare instances, development secondary to invasive diagnostic or therapeutic procedures [12]. The definition of EMP in MM has varied among studies. Some reports classify EMP only in cases of organ or tissue infiltration through hematogenous dissemination, but others classify soft-tissue developing from bones through direct growth from skeletal tumors [1, 11, 13]. According to Laura Rosiñol et al., two distinct patterns of soft-tissue involvement in MM can be identified: EMP or extra-osseous type, characterized by lesions confined to soft tissues without direct bone contact and paraskeletal plasmacytomas, defined as soft-tissue masses that originate from bone lesions [1].
Due to the lack of consistent classification between EMP and para-skeletal plasmacytomas in published studies, accurate statistics on their respective incidence and outcomes remain uncertain. Available data on the incidence of plasmacytomas in MM are based primarily on observational studies. The frequency of EMP at the time of diagnosis has been reported to range from 1.7% to 4.5%, whereas paraskeletal plasmacytomas are observed in approximately 7% to 34.4% of patients [1].
The small number of reported cases and the absence of controlled studies limit the ability to assess the true efficacy of current treatments for soft-tissue involvement in MM, and therefore no standardized therapeutic approach can be recommended [1, 13]. The National Inpatient Sample data suggest that treating spinal involvement in MM should include a multimodal strategy with chemotherapy, bisphosphonates, radiation therapy, and surgery [5].
Alkylating agents, particularly high-dose melphalan, remain effective frontline therapy for patients with paraskeletal involvement, showing comparable response and survival rates to those without soft-tissue disease [1, 14, 15]. Autologous stem cell transplantation (ASCT) provides similar outcomes in paraskeletal cases. Data on newer agents are limited: bortezomib appears more effective in para-skeletal than in EMP, while carfilzomib and immunomodulatory agents show reduced activity [1, 14]. Proteasome inhibitor-based regimens remain the most effective therapeutic option for patients with para-skeletal plasmacytomas. Combinations such as Dara-VMP (daratumumab, bortezomib, melphalan, prednisolone) or VRD are preferred, particularly in those not eligible for immediate ASCT [1, 14]. These data were proved by our two case reports, which showed high treatment effectiveness with VRD regimen.
In a retrospective analysis by Vittorio Montefusco et al., data from 2,332 newly diagnosed MM patients enrolled in eight FoNeSa Onlus and HOVON Foundation clinical trials were evaluated. Three of these trials included transplant-eligible and five transplant-ineligible patients. Treatment protocols varied among the studies. Three trials used an immunomodulatory agent (mostly lenalidomide), three included a proteasome inhibitor and four combined both types of therapy. Maintenance therapy was provided in six trials. Among all participants, 267 patients (11%) presented with soft-tissue plasmacytomas (243 paraskeletal, 12 extramedullary and 12 unclassified). Median progression-free survival was 26.1 months for patients with EMP and 25.2 months for those without plasmacytomas, while median overall survival reached 70.1 months and 79.9 months respectively [12, 16].
Currently, the International Myeloma Working Group provides no specific recommendations regarding the optimal frequency of plasmacytoma assessment. Clinical evaluation of palpable lesions should be performed at the beginning of each treatment cycle while PET/CT or MRI should be repeated approximately three months after therapy initiation to assess residual activity. If the disease persists, doctors should consider continuing the current treatment, adding local radiotherapy or switching to another systemic regimen, depending on how well the paraprotein levels and plasmacytoma have responded. If the reduction in plasmacytoma size is less than 50%, local radiotherapy and/or modification of systemic therapy should be considered. Continuation of the current therapeutic regimen is recommended when the lesion decreases by 50% or more [1].
There is no clear consensus on the use of radiotherapy in extramedullary myeloma, except for solitary plasmacytoma [15]. Prompt local radiotherapy is indicated in cases of spinal cord compression and should also be considered for patients with severe compressive pain, bulky plasmacytomas or residual localized disease following systemic treatment [1].
According to the Surgeon’s Committee of the Chinese Myeloma Working Group of the International Myeloma Foundation, extramedullary plasmacytomas located in the limbs or spine should be managed surgically through intralesional, marginal or wide excision. Wide excision is recommended as the preferred approach, while marginal excision serves as an alternative when wide resection is not feasible. Radiotherapy should be administered after intralesional removal. The treatment plan should be developed together by a multidisciplinary team including surgeons, hematologists and radiation oncologists. Since surgery in MM is not aimed at achieving a radical cure, the focus is on relieving symptoms and improving the patient’s quality of life. Surgical treatment primarily seeks to prevent or stabilize pathological fractures, decompress the spinal cord and nerve roots, reduce pain, restore mobility and maintain the structural stability of the spine and surrounding bone [17].
According to Jiajia Zhang et al., patients with MM and spinal canal invasion by extramedullary plasmacytoma were treated either with surgery plus chemotherapy or chemotherapy alone, mainly using bortezomib-based regimens. The study emphasized the importance of early detection of spinal involvement and showed that extramedullary disease responded well to novel agents. Surgical decompression was advised in cases of neurological compression to relieve symptoms and prevent further damage [18].
Martio et al. reported a case of a 75-year-old female with an epidural extramedullary plasmacytoma extending from T6 to L1. The patient underwent surgical decompression followed by systemic chemotherapy with bortezomib, cyclophosphamide and dexamethasone. This combined approach resulted in complete radiological remission with no residual or recurrent disease observed eight months postoperatively and sustained remission for more than fifteen months [19].
It is clear that every clinical case is unique and necessitates a cohesive and systematic evaluation before determining the most appropriate treatment strategy: chemotherapy, surgery, radiotherapy or its combinations. The comprehensive assessment for surgery indication was put forth by Fisher et al. [20] and Bilsky et al. [21], who have independently created practical assessment scales that facilitate the accurate and tailored evaluation of indications for surgical intervention in spinal tumor lesions.
Fisher et al. developed an evidence-based classification system for assessing spinal instability in patients with neoplastic disease of the spine. Their SINS incorporates six components: tumor location, mechanical pain, bone lesion quality, spinal alignment, vertebral body collapse, and posterolateral spinal element involvement. It helps to generate a comprehensive stability score ranging from 0 to 18. Scores stratify patients into stable (0-6 points), potentially unstable (7-12 points), or unstable (≥13 points) categories, thereby guiding neurosurgical consultation and management. The authors emphasized that spinal instability is one of multiple factors influencing treatment decisions, alongside neurological status, tumor histology, and patient-specific considerations. The study provides clinicians with a standardized framework to improve multidisciplinary communication and optimize care for patients with spinal neoplasia [20].
Bilsky et al. reported the development and validation of a six-point MRI-based grading system for epidural spinal cord compression (ESCC) in metastatic spinal disease, demonstrating that the scale provides good to excellent interrater and intrarater reliability, particularly when utilizing axial T2-weighted images. Their study emphasized the importance of distinguishing subtle degrees of thecal sac deformation and spinal cord abutment to inform surgical decision-making and stereotactic radiosurgery planning. The authors concluded that this refined ESCC grading scale facilitates consistent classification of spinal cord compression, thereby enhancing communication across surgical and radiation oncology disciplines and offering a standardized framework applicable to multi-institutional clinical trials and treatment outcome assessments [21].
Bobinski et al. defined a significant correlation between higher SINS values and more advanced grades of ESCC in patients surgically treated for spinal metastases. These findings suggest that elevated SINS scores may serve as a reliable indicator of increased risk for the development of ESCC, reflecting the progressive biomechanical compromise of vertebral integrity due to metastatic disease. The study supports the clinical value of SINS as a tool for assessing tumor-associated spinal instability and the risk of ESCC [22].
Consequently, in the line with the presented double-case report findings, surgical intervention in extramedullary spinal plasmacytoma should be reserved for instances when high SINS scores (≥13 points) indicate mechanical instability and/or elevated ESCC grades reflect severe or progressive spinal cord compression refractory to systemic chemotherapy. It is strongly advised to evaluate these two scales when making decisions regarding the treatment strategy for patients with extramedullary spinal plasmacytomas.
Conclusion
Thus, summarizing the results of numerous studies, surgical treatment of extramedullary spinal plasmacytoma in patients with multiple myeloma should not be considered mandatory, and is indicated exclusively in cases of emergency spinal cord decompression after ineffective chemotherapy with novel agents, or for the purpose when solitary plasmacytoma is suspected in the absence of bone marrow infiltration by plasma cells.
Early diagnosis of extramedullary spinal plasmacytoma in multiple myeloma is crucial for preventing irreversible neurological complications and improving long-term outcomes without surgical intervention. The management of such cases should be based on a comprehensive, multidisciplinary approach that combine systemic chemotherapy, radiological assessment and, when indicated, surgical or radiation therapy. Collaboration among hematologists, radiologists and neurosurgeons is essential for optimizing treatment strategy.
Disclosure
Conflict of interest
The authors declare no conflict of interest.
Informed consent
Informed consent was obtained from both patients.
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