无全身性疾病证据的髓外浆细胞瘤占所有浆细胞肿瘤的比例不到 5%。甲状腺区域髓外浆细胞瘤的发病率极其罕见。本报告讨论一名 72 岁男性甲状腺髓外浆细胞瘤的病例。患者因右侧甲状腺结节增大而接受甲状腺全切除术，术中发现浆细胞瘤有包膜外成分，与区域软组织粘连，并累及右侧喉神经和区域淋巴结。尽管最初对多发性骨髓瘤进行了全面的阴性检查，包括骨髓活检和血液学检查，但在明确的放射治疗后，疾病进展为多发性骨髓瘤，代谢亢进溶解性病变的发展和进一步的病理检查证明了这一点。该患者的治疗过程包括全身化疗和自体干细胞移植，取得了良好的治疗反应。尽管已制定指南，但多发性骨髓瘤的进展凸显了密切观察的必要性以及创新治疗策略来管理这种罕见实体的潜力。版权所有 © 2024，Alexander 等人。

Extramedullary plasmacytomas without evidence of systemic illness make up less than 5% of all plasma cell neoplasms. The incidence of extramedullary plasmacytoma of the thyroid region is exceedingly rare. This report discusses the case of a 72-year-old male with extramedullary plasmacytoma of the thyroid. The patient underwent a total thyroidectomy for an enlarging right-sided thyroid nodule, and intraoperatively, the plasmacytoma was found to have an extracapsular component with adherence to the regional soft tissue as well as involvement of the right laryngeal nerve and regional lymph nodes. Despite a comprehensive negative workup for multiple myeloma initially, including a bone marrow biopsy and hematologic workup, the disease progressed to multiple myeloma following definitive radiation therapy, as evidenced by the development of hypermetabolic lytic lesions and further pathological examination. The patient's treatment course included systemic chemotherapy and an autologous stem cell transplant, resulting in a favorable treatment response. The progression to multiple myeloma despite established guidelines highlights the need for close observation and the potential for innovative therapeutic strategies to manage this rare entity.Copyright © 2024, Alexander et al.