Extramedullary plasmacytoma with associated multiple myeloma as a presentation of the posterior mediastinal mass: a rare clinical encounter.

A plasmacytoma is a single, isolated tumour of abnormal plasma cells. It can develop within the bone, known as solitary plasmacytoma of bone, or outside the bone, referred to as extraosseous (extramedullary) plasmacytoma, without spreading to other parts of the body. Plasmacytoma, an uncommon presentation in the posterior mediastinum, usually arises as solitary or multiple lesions in bone or soft tissues. The standard treatment involves definitive radiotherapy, potentially curative for extramedullary cases. The prognosis varies, being more favourable without concurrent multiple myeloma and worsening with high-risk cytogenetics. The case involves a male in his early 80s with an extensive medical history presenting with difficulty swallowing and dyspnoea. The diagnosis revealed a rare posterior mediastinal plasmacytoma associated with multiple myeloma, emphasising the importance of prompt diagnosis and treatment.

Skull base plasmacytoma in young patients aged below 40 years: Radiological perspectives and clinical outcomes.

BACKGROUND: Plasmacytoma of the skull base is a rare manifestation of plasma cell neoplasm with only a few cases documented in literature involving young adults. Plasmacytoma can be an isolated solitary lesion or a secondary manifestation of multiple myeloma (MM). In this study, we report the clinical and radiological characteristics, management, and outcomes of patients under the age of 40 who presented with skull base plasmacytoma and associated neurological manifestations. Additionally, we share our experience in treating a rare case of skull base plasmacytoma diagnosed during pregnancy, in which the patient exhibited a favorable response to myeloma treatment initiated after delivery. CASE SERIES: Four patients were identified, comprising one pregnant female and three male patients, with a median age of 36 years (range 33-37 years). The main presenting symptoms were headache, dizziness, and cranial nerve palsy. All patients received underwent systemic myeloma therapy and radiotherapy with three patients also underwent autologous stem cell transplantation (ASCT). Notably, all patients achieved complete remission. CONCLUSION: Skull base plasmacytoma represents a rare manifestation of plasma cell neoplasms, underscoring the importance of considering it in the differential diagnosis of skull base lesions to ensure early intervention and avoid potential serious complications. Throughout our series, the cornerstone of therapy involved radiotherapy, systemic myeloma therapy, and ASCT, all of which elicited a favorable response in every case.

IgA multiple myeloma-associated mediastinal spinal plasmacytoma presenting as spinal cord compression.

Multiple myeloma associated with extramedullary plasmacytoma at initial presentation is rare. We describe a case of a man in his 30s who initially presented with symptoms of spinal cord compression. Further imaging revealed a mediastinal tumour, with a biopsy confirming plasmacytoma. Immunofixation revealed IgA lambda paraprotein. Bone marrow biopsy demonstrated atypical T-cell cytotoxic proliferation and trilineage hypoplasia. The patient was diagnosed with extramedullary plasmacytoma with active IgA multiple myeloma. The patient received mediastinal radiation to the tumour, followed by anti-myeloma therapy. This diagnosis is critical as managing a solitary plasmacytoma drastically differs from an extramedullary plasmacytoma with active multiple myeloma.

A Plasmacytoma of the Lateral Pharyngeal Wall: A Diagnostic Enigma.

Plasmacytoma is a rare plasma cell dyscrasia that grows in bones or soft tissues such as the pharynx. Soft tissue plasmacytomas are rare, and a higher burden has been reported in the upper aero-digestive tract, often manifesting as hoarseness, dysphagia, or odynophagia. Due to their rarity, extramedullary plasmacytomas (EMPs) have unknown prognostic factors, and guidelines for optimal management are still lacking. However, radiation therapy and surgery have been used with positive outcomes. Herein, we describe a unique case of plasmacytoma of the pharyngeal tissue in a male patient with a history of HIV disease. The patient completed 28 sessions of radiation therapy, resulting in an improvement in his throat pain and hoarseness. Given the patient's age and lack of traditional risk factors for head and neck cancers, his hoarseness and odynophagia proved to be a diagnostic conundrum. Although infrequent, soft tissue plasmacytomas should be considered in the differential diagnosis of head and neck tumors.

Spontaneous regression of multiple solitary plasmacytoma harboring Epstein-Barr virus: a case report and literature review.

We report a rare case of spontaneous regression (SR) in an elderly untreated patient with multiple solitary plasmacytoma (MSP). Diagnosis of MSP was confirmed through surgical resection of the left nasal cavity mass and subsequent biopsy of the right humerus. The patient was considered ineligible for chemotherapy due to poor performance status. At 3-month post-diagnosis, the patient's condition worsened with deteriorating bone lesions and emergence of a new serum monoclonal protein. However, these clinical findings completely disappeared at 6 months, and positron emission tomography-computed tomography at 1 year confirmed complete metabolic remission. Notably, peripheral blood lymphocyte counts were inversely correlated with tumor progression and remission. Pathological re-evaluation of the initial biopsy specimens revealed programmed cell death protein 1 (PD-1) expression in tumor-infiltrating CD8+ T cells. In addition, tumor cells were infected with Epstein-Barr virus (EBV) but were negative for programmed cell death ligand 1 (PD-L1) expression, which is the most potent immune escape mechanism in tumor cells. While the mechanism underlying SR remains unclear, our findings suggest that host immune response as well as EBV infection may contribute to SR. Further studies are needed to elucidate the clinicopathologic mechanisms of tumor regression in plasma cell neoplasms.

Successful Treatment of Refractory Orbital Plasmacytoma with Chimeric Antigen Receptor T Cell Therapy: A Case Report and Review of the Literature.

Orbital plasmacytoma is a rare plasma cell tumor that may arise as an aggressive form of extramedullary multiple myeloma. Treatment modalities include surgical excision, radiation, and chemotherapy. Chimeric antigen receptor T cell therapy is currently reserved for refractory disease. The authors present a case of a 69-year-old woman with an extensive orbital plasmacytoma refractory to multimodal therapy who was treated with idecabtagene vicleucel chimeric antigen receptor T cell therapy. Four days after infusion, the patient exhibited grade 1 cytokine release syndrome, which resolved with tocilizumab. The orbital plasmacytoma significantly decreased in size 1 month after treatment and demonstrated complete serological response and sustained tumor burden reduction at 10-month follow-up. This case highlights the efficacy of chimeric antigen receptor T cell therapy for refractory orbital plasmacytoma and calls attention to potential inflammatory toxicities.

[Consensus for the diagnosis and management of extramedullary plasmacytoma in China(2024)].

Extramedullary plasmacytoma (EMP) is a special type of malignant plasmacytosis, which is complex and heterogeneous. Most EMP patients have poor prognosis and lack a stratified prognostic system or ideal treatment strategy supported by evidence-based medical evidence, which cannot meet clinical needs. In order to improve the understanding of this disease entity, Plasma Cell Disease Group, Chinese Society of Hematology, Chinese Medical Association and Chinese Myeloma Committee-Chinese Hematology Association developed the "Chinese Expert Consensus on the diagnosis and treatment of extramedullary plasmacytoma", which aims to standardize the clinical diagnosis and treatment of EMP and ultimately improve the overall survival of patients with plasmacytoma.

Skeletal muscle extramedullary plasmacytoma transformed into plasmablastic plasmacytoma: a case report.

BACKGROUND: Extramedullary plasmacytoma (EMP) is a rare plasma cell malignancy, especially when the tumor originates in skeletal muscle. Plasmablastic plasmacytoma is an anaplastic round cell tumor with highly malignancy and poor prognosis. To date, there have been no reports on the transformation of skeletal muscle EMP into plasmablastic plasmacytoma. Therefore, the diagnosis, treatment, and prognosis of cases of this pathologic transformation are unclear. CASE PRESENTATION: This article reports a case of an elderly male patient who presented with a painless mass in the right calf and was diagnosed with EMP by puncture pathology. Complete remission was obtained after sequential chemoradiotherapy. 6 months later, another puncture was performed due to plasmablastic plasmacytoma multiple distant metastases, and the pathology showed that EMP was transformed to plasmablastic plasmacytoma. Despite aggressive antitumor therapy, the disease continued to deteriorate, and the patient ultimately died of respiratory failure. CONCLUSION: The transformation of EMP into plasmablastic plasmacytoma is very rare, and its diagnosis and treatment require the participation of both experienced pathologists and clinicians. We report this case in order to raise clinicians' awareness of the diagnosis and treatment of EMP and its transformation to plasmablastic plasmacytoma, and to avoid misdiagnosis and underdiagnosis.

Extramedullary Plasmacytoma of the Penis as a First Manifestation of Multiple Myeloma: A Case Report.

INTRODUCTION: Plasmacytoma is a rare plasma-cell neoplasm, which includes bone and extramedullary types. While most cases occur in the head and neck, our report presents an unusual case of extramedullary plasmacytoma (EMP) in the penis, emphasizing the diverse locations of this condition. CASE PRESENTATION: An 88-year-old man, post-hydrocelectomy, presented with a palpable penile mass causing urinary symptoms. CT scans revealed a tumor with extracapsular spread and potential urethral involvement. Biopsy confirmed lymphoma, later identified as extramedullary plasmacytoma. A follow-up whole-body CT scan was performed, revealing multiple areas of bone rarefaction of the dens of the axis. His diagnosis has been further specified as multiple myeloma. Treatment with lenalidomide, bortezomib, and dexamethasone led to significant penile tumor reduction and improved voiding symptoms after three cycles. CONCLUSION: A rare case of primary EMP in the penis is reported, with only two documented cases of EMP in this location. The etiology of EMP remains unclear, possibly linked to chronic infection, irritation, or inflammation. EMP typically occurs in soft tissues, commonly in the head and neck, presenting as submucosal masses with symptoms in individuals aged 50-70. Diagnosis requires demonstrating monoclonal plasma cell infiltration and excluding multiple myeloma. While EMPs are often treated with radiotherapy, a patient with bone rarefaction suggestive of multiple myeloma requires first-line chemotherapy. This case highlights the importance of recognizing myeloma-defining events for appropriate treatment.

Adenopathy and an Extensive Skin Patch Overlying a Plasmacytoma Syndrome.

This case report describes a central cobblestone-like mass and bone lesion on the spinous process of the L3 vertebra underlying the skin mass.

Renal AA amyloidosis revealing extramedullary plasmocytoma / Amylose rénale AA révélant un plasmocytome extra-médullaire : étude de cas

Introduction: Solitary plasmacytoma is a rare, localized malignancy. Bone localizations are the most common. Extramedullary plasmacytomas are much rarer. They are most often in the upper respiratory tract and can be complicated by amyloidosis. Here is an original report of a mediastinal extramedullary plasmacytoma revealed by type AA renal amyloidosis. Case presentation: We present the case of a 52-year-old patient with mediastinal extramedullary plasmocytoma diagnosed by renal failure due to type AA renal amyloidosis. Treatment was based on surgery with chemotherapy based on prednisone and melphalan. The patient presented end-stage renal failure that required hemodialysis at discharge. Conclusion: Extramedullary plasmacytoma is a rare tumour that may be associated with amyloidosis, usually type AL. To our knowledge, its association with AA amyloidosis has not been reported in the literature. Treatment is based on surgery combined with radiotherapy or chemotherapy.

Introduction: Le plasmocytome solitaire est une tumeur maligne rare localisée. Les localisations osseuses sont les plus fréquentes. Les plasmocytomes extra­médullaires (PEM) sont beaucoup plus rares, localisés le plus souvent au niveau des voies respiratoires supérieures. Présentation du cas: Nous rapportons une observation de PEM médiastinal révélé par une insuffisance rénale en rapport avec amylose rénale de type AA chez un patient âgé de 52 ans. Le traitement a comporté une tumorectomie de la masse associée à une chimiothérapie. Sur le plan rénal, le patient était au stade d'insuffisance rénale terminale nécessitant le recours à l'hémodialyse chronique. Conclusion: Le PEM est une tumeur rare pouvant se compliquer d'une amylose le plus souvent de type AL. Son association à une amylose AA n'a pas été rapportée auparavant à notre connaissance. Le traitement est basé surtout sur la chirurgie associée à une radiothérapie ou chimiothérapie.

A Rare Case of Subcutaneous Amyloidoma Associated with Localized Lymphoplasmacytic Lymphoma: Diagnostic Challenges and Treatment Considerations.

BACKGROUND AL amyloidomas are solitary, localized, tumor-like deposits of immunoglobulin light-chain-derived amyloid fibrils in the absence of systemic amyloidosis. A rare entity, they have been described in various anatomical sites, typically in spatial association with a sparse lymphoplasmacytic infiltrate, ultimately corresponding to a clonal, malignant, lymphomatous disorder accounting for the amyloidogenic activity. Most frequently, the amyloidoma-associated hematological disorder corresponds to either a solitary plasmacytoma or an extranodal marginal zone lymphoma of MALT. Much rarer is the association with lymphoplasmacytic lymphoma, which by itself is usually a bone marrow-bound disorder with systemic burden. The almost anecdotic combination of an amyloidoma and a localized lymphoplasmacytic lymphoma deserves attention, as it entails a thorough diagnostic workup to exclude systemic involvement and a proportionate therapeutic approach to avoid overtreatment. A review of the literature provides an insight on pathogenesis and prognosis, and can assist both pathologists and clinicians in establishing optimal patient management strategies. CASE REPORT We herein report the incidental finding of a subcutaneous amyloidoma caused by a spatially related, similarly localized lymphoplasmacytic lymphoma diagnosed in a 54-year-old female patient with no other disease localizations and a complete remission following 2 subsequent surgical excisions. CONCLUSIONS Whatever the specific combination of an amyloidoma and the related hematological neoplasm, a multidisciplinary collaboration and a comprehensive clinical-pathological staging are warranted to exclude systemic involvement and identify patients with localized diseases who would benefit from local active treatment and close follow-up.

Hematological entities with plasmacytic differentiation: a case report.

INTRODUCTION: Plasmacytoma, a localized tumor of monoclonal plasma cells without any clinical, radiological or physical evidence of plasma cell neoplasm (PCN), is a rare entity that accounts for 1% of PCN. Immunoglobulin M (IgM) extramedullary plasmacytoma of mediastinal region has never been reported and is a diagnostic challenge considering other differential diagnoses. CASE PRESENTATION: We present the case of a 51-year-old African-American female with progressively increasing cough, dyspnea, and dysphagia for 6 months with a computed tomography (CT) scan revealing a subcarinal mass. The histopathological analysis of the mass reveals a diagnosis of lymphoma with plasma cell differentiation, with a differential of lymphoplasmacytic lymphoma and plasma cell neoplasm. The lymphoma panel via next-generation sequencing (NGS) and a myeloma-targeted fluorescent in situ hybridization (FISH) panel confirmed the diagnosis of IgM extramedullary plasmacytoma, an entity of rare occurrence. Treatment with radiation led to complete regression of the plasmacytoma with normal blood work-up. CONCLUSIONS: This report describes the challenges of diagnosing IgM extramedullary plasmactyoma. Our case report highlights the importance of cytogenetics and NGS in establishing a correct diagnosis that indeed has prognostic and therapeutic implications.

Rapidly Enlarging Parotid Mass in a Person Living with HIV: A Case of Multiple Myeloma with Extramedullary Plasmacytoma.

BACKGROUND The differential diagnosis for a parotid mass is broad, including infectious, autoimmune, and neoplastic etiologies. In people with HIV, regardless of viral suppression or immune status, neoplastic causes are more common. This report describes the evaluation of a woman with a large parotid mass, with an ultimate diagnosis of multiple myeloma with extramedullary plasmacytoma. CASE REPORT A 51-year-old woman with HIV infection presented with headache, weight loss, and right facial mass that was present for 5 years but more rapidly enlarging in the prior year. CD4 count was 234 cells/mL, and HIV RNA was 10 810 copies/mL. Physical examination was significant for a large deforming right-sided facial mass, decreased sensation in the V1 and V2 distributions, and right-sided ophthalmoplegia and ptosis. MRI and PET/CT scan confirmed a metabolically active large parotid mass with extension into the cavernous sinus. An IgG kappa monoclonal spike was present on serum protein electrophoresis. Incisional biopsy of the facial mass showed atypical lymphoid cells with plasmablastic and plasmacytic morphology with a high mitotic rate and proliferation index. She was diagnosed with R-ISS stage II IgG kappa multiple myeloma with extramedullary plasmacytoma, and initiated on chemotherapy, radiation, and antiretroviral therapy. CONCLUSIONS A rapidly enlarging parotid mass should prompt timely evaluation and biopsy for definitive diagnosis, particularly in immunocompromised patients, including people with HIV. Extramedullary plasmacytomas have a more aggressive disease process in people with HIV and are associated with high-risk multiple myeloma and progression, as seen in this patient.

Epidemiology and survival of primary extraosseous plasmacytoma: insights from a population-based study with a 20-year follow-up.

Primary extraosseous plasmacytoma (PEP) is a rare and localized form of plasmacytoma that is not well understood. This study aimed to investigate the clinical features and prognostic factors associated with PEP. Using the Surveillance, Epidemiology, and End Results (SEER) database, a total of 1044 patients diagnosed with PEP between 2000 and 2019 were identified. The average age was 60.3 ± 15.2 years, with 64.3% being male (male: female = 1.8:1) and 53.8% being over 60-year old. The survival outcome of patients with PEP depends on several factors including age, race, marital status, and treatment options such as chemotherapy, radiotherapy, and surgery, which were also identified as independent predictors of overall survival for PEP. Patients who were younger, Asian or Pacific Islander, American Indian or Native American, and received radiotherapy or surgery had a more favorable prognosis, while those who underwent chemotherapy had poorer outcomes.