Mandibular Plasmacytoma Relapse of Multiple Myeloma Masquerading as MRONJ: A Diagnostic Pitfall in Post-ASCT Surveillance: A Case Report
-
Faezeh Khozeimeh
,
Mohammad Hosein Amirzade-Iranaq
,
Elahe Soufian
,
Seyed Amirhossein Rahimizadeh Hosseini
,
Laleh Maleki
Abstract
Isolated plasmacytoma relapse of multiple myeloma (MM) is uncommon and portends a poor prognosis; mandibular involvement is exceptionally rare, and its clinical presentation in the post-autologous stem cell transplantation (ASCT) setting, particularly in patients with prior bisphosphonate exposure, can closely mimic medication-related osteonecrosis of the jaw (MRONJ), creating a critical diagnostic pitfall. A 62-year-old male with MM in sustained remission following ASCT and lenalidomide maintenance presented with a seven-month history of a non-healing extraction socket and progressive exophytic mandibular mass. Prior zoledronic acid therapy led to an initial diagnosis of MRONJ, delaying biopsy. Clinical examination revealed a 4×3 cm firm mass with lingual bone exposure; contrast-enhanced CT demonstrated osteolytic cortical destruction with inferior alveolar canal invasion and indeterminate incidental vertebral lytic foci. Incisional biopsy confirmed sheets of atypical plasma cells with eccentric nuclei and prominent mitotic activity, consistent with plasmacytoma. Comprehensive systemic workup, including bone marrow biopsy and serum protein electrophoresis, confirmed the absence of systemic MM relapse. The patient was treated with external beam radiotherapy (40 Gy in 20 fractions), achieving significant lesion regression. Focal residual bone exposure (<1 cm) attributed to combined bisphosphonate-radiation osteonecrosis was managed conservatively. The patient reported functional recovery and maintained acceptable quality of life at the three-month follow-up, with no evidence of local recurrence or systemic relapse. This case highlights that persistent oral lesions in MM patients must not be reflexively attributed to MRONJ without histopathological verification, especially when lesions fail to resolve following bisphosphonate cessation. Multidisciplinary surveillance at the oncology–dentistry interface is essential to avoid diagnostic delay in this vulnerable population. Keywords: Multiple myeloma; Plasmacytoma; Mandibular neoplasms; Stem cell transplantation; Case report.
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15. Kujanpaa M, Vuollo V, Tiisanoja A, Laitala ML, Sandor GK, Karki S. Incidence of medication-related osteonecrosis of the jaw and associated antiresorptive drugs in adult Finnish population. Sci Rep. 2025;15(1):17377.
16. Wang YN, Zhang CW, Gao YX, Ge XL. The Progress of Autologous Hematopoietic Stem Cell Transplantation in the Treatment of Multiple Myeloma (Review). Technol Cancer Res Treat. 2025;24:15330338251321349.
17. Bladé J, Beksac M, Caers J, Jurczyszyn A, von Lilienfeld-Toal M, Moreau P, et al. Extramedullary disease in multiple myeloma: a systematic literature review. Blood Cancer Journal. 2022;12(3):45.
18. Rezaei F, Nazari H, Izadi B. Solitary Plasmacytoma in the Mandible Resembling an Odontogenic Cyst/Tumor. Case Rep Dent. 2016;2016:3629047.
19. Dimopoulos MA, Merlini G, Bridoux F, Leung N, Mikhael J, Harrison SJ, et al. Management of multiple myeloma-related renal impairment: recommendations from the International Myeloma Working Group. The Lancet Oncology. 2023;24(7):e293-e311.
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22. Cowan AJ, Green DJ, Kwok M, Lee S, Coffey DG, Holmberg LA, et al. Diagnosis and management of multiple myeloma: a review. Jama. 2022;327(5):464-77.
23. Chu TH, Jung SH, Kim K, Lee JH, Mun YC, Bang SM, et al. Relapse with plasmacytoma after upfront autologous stem cell transplantation in multiple myeloma. Ann Hematol. 2022;101(6):1217-26.
24. Ríos-Sánchez A, Riazzo-Benítez MA, Ríos-Tamayo R. The Current Role of Physiotherapy in Systemic Light-Chain (AL) Amyloidosis and Multiple Myeloma. Life (Basel). 2026; 16(6):1018.
2. Kumar S, Paiva B, Anderson KC, Durie B, Landgren O, Moreau P, et al. International Myeloma Working Group consensus criteria for response and minimal residual disease assessment in multiple myeloma. Lancet Oncol. 2016;17(8):e328-e46.
3. Gay F, Marchetti E, Bertuglia G. Multiple Myeloma Unpacked. Hematol Oncol. 2025; 43 Suppl 2:e70067.
4. Silberstein J, Tuchman S, Grant SJ. What is multiple myeloma? Jama. 2022;327(5):497-.
5. Padala SA, Barsouk A, Barsouk A, Rawla P, Vakiti A, Kolhe R, et al. Epidemiology, staging, and management of multiple myeloma. Medical Sciences. 2021;9(1):3.
6. Rajkumar SV. Multiple myeloma: 2022 update on diagnosis, risk stratification, and management. American journal of hematology. 2022;97(8):1086-107.
7. Wan X, Yu T, Yu T, Cai H. The impact of multiple myeloma drug treatments on autologous stem cell transplantation in the era of new drugs. Front Oncol. 2025;15:1479164.
8. Caers J, Paiva B, Zamagni E, Leleu X, Blade J, Kristinsson SY, et al. Diagnosis, treatment, and response assessment in solitary plasmacytoma: updated recommendations from a European Expert Panel. J Hematol Oncol. 2018;11(1):10.
9. Chittemsetti S, Guttikonda VR, Sravya T, Manchikatla PK. Solitary plasmacytoma of mandible: A rare entity. J Oral Maxillofac Pathol. 2019;23(1):136-9.
10. Pol JN, Patil DB, Desai SS, Calcuttawala AB. Plasmacytoma of the mandible: A diagnostic conundrum. IP Journal of Diagnostic Pathology and Oncology. 2021;6(4):272-7.
11. Renuga S, Sahana N, Yadav S, Khatoon H, Kulkarni M, Verghese R. Solitary Plasmacytoma of Mandible Transforming to Multiple Myeloma?-A Rare Case Report. BIOCHEMISTRY. 2024;11:4.
12. Suryavanshi H, Patankar S, Dhumal S, Choudhari S. Solitary plasmacytoma of jaw bone: a case report and systematic review of fifty cases from literature. Journal of Oral and Maxillofacial Pathology. 2021;25(1):205.
13. Jimenez-Segura R, Rosinol L, Cibeira MT, Fernandez de Larrea C, Tovar N, Rodriguez-Lobato LG, et al. Paraskeletal and extramedullary plasmacytomas in multiple myeloma at diagnosis and at first relapse: 50-years of experience from an academic institution. Blood Cancer J. 2022;12(9):135.
14. Debortoli C, Latreche S, Rios O, Savoldelli C. Mandibular bony solitary plasmacytoma: a misleading case. Wiley; 2025.
15. Kujanpaa M, Vuollo V, Tiisanoja A, Laitala ML, Sandor GK, Karki S. Incidence of medication-related osteonecrosis of the jaw and associated antiresorptive drugs in adult Finnish population. Sci Rep. 2025;15(1):17377.
16. Wang YN, Zhang CW, Gao YX, Ge XL. The Progress of Autologous Hematopoietic Stem Cell Transplantation in the Treatment of Multiple Myeloma (Review). Technol Cancer Res Treat. 2025;24:15330338251321349.
17. Bladé J, Beksac M, Caers J, Jurczyszyn A, von Lilienfeld-Toal M, Moreau P, et al. Extramedullary disease in multiple myeloma: a systematic literature review. Blood Cancer Journal. 2022;12(3):45.
18. Rezaei F, Nazari H, Izadi B. Solitary Plasmacytoma in the Mandible Resembling an Odontogenic Cyst/Tumor. Case Rep Dent. 2016;2016:3629047.
19. Dimopoulos MA, Merlini G, Bridoux F, Leung N, Mikhael J, Harrison SJ, et al. Management of multiple myeloma-related renal impairment: recommendations from the International Myeloma Working Group. The Lancet Oncology. 2023;24(7):e293-e311.
20. Raje NS, Anaissie E, Kumar SK, Lonial S, Martin T, Gertz MA, et al. Consensus guidelines and recommendations for infection prevention in multiple myeloma: a report from the International Myeloma Working Group. The Lancet Haematology. 2022;9(2):e143-e61.
21. Cooperrider JH, Derman BA. Minimal Residual Disease Negativity as the Primary Goal of Multiple Myeloma Therapy. Drugs. 2025;85(10):1231-51.
22. Cowan AJ, Green DJ, Kwok M, Lee S, Coffey DG, Holmberg LA, et al. Diagnosis and management of multiple myeloma: a review. Jama. 2022;327(5):464-77.
23. Chu TH, Jung SH, Kim K, Lee JH, Mun YC, Bang SM, et al. Relapse with plasmacytoma after upfront autologous stem cell transplantation in multiple myeloma. Ann Hematol. 2022;101(6):1217-26.
24. Ríos-Sánchez A, Riazzo-Benítez MA, Ríos-Tamayo R. The Current Role of Physiotherapy in Systemic Light-Chain (AL) Amyloidosis and Multiple Myeloma. Life (Basel). 2026; 16(6):1018.
| Files | ||
| Issue | Vol 13, No 3 (Summer 2026) | |
| Section | Case Report(s) | |
| Keywords | ||
| Multiple myeloma; Plasmacytoma; Mandibular neoplasms; Stem cell transplantation; Case report. | ||
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How to Cite
1.
Khozeimeh F, Amirzade-Iranaq MH, Soufian E, Rahimizadeh Hosseini SA, Maleki L. Mandibular Plasmacytoma Relapse of Multiple Myeloma Masquerading as MRONJ: A Diagnostic Pitfall in Post-ASCT Surveillance: A Case Report. J Craniomaxillofac Res. 2026;13(3):385-392.
