背景 胆腺肿块的鉴别诊断范围广泛，包括感染性、自身免疫性和肿瘤性病因。不论HIV感染者的病毒抑制或免疫状态，肿瘤性原因更为常见。本报告描述了一例巨大胆腺肿块的评估，最终诊断为多发性骨髓瘤伴有髓外浆细胞瘤。 病例报告 一名51岁的HIV感染女性因头痛，体重减轻和右脸部肿块就诊，肿块已存在5年，但在过去一年内迅速增大。CD4计数为234个细胞/毫升，HIV RNA为10,810拷贝/毫升。体格检查显示右侧面部有巨大的扭曲性肿块，V1和V2区域感觉减退，右侧眼肌麻痹和眼睑下垂。MRI和PET/CT扫描证实代谢活跃的巨大胆腺肿块扩展到海绵窦。血清蛋白电泳显示IgGκ单克隆峰。脸部肿块的切口活检显示异型淋巴细胞，有浆母细胞和浆细胞样形态，有高度有丝分裂指数和增殖指数。诊断为R-ISS II期IgGκ多发性骨髓瘤伴有髓外浆细胞瘤，并开始化学治疗、放疗和抗逆转录病毒治疗。 结论 快速增大的胆腺肿块应提示及时评估和活检以获得明确诊断，特别是在免疫功能受损的患者中，包括HIV感染者。在HIV感染者中，髓外浆细胞瘤具有更为侵袭性的疾病过程，并与高风险多发性骨髓瘤和病情进展有关，正如本患者的情况所示。

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.