Shamas Tiffany, Reynolds Conner D, Garcia Ryan R, Doescher Rosalie, Fuchs Deborah, Rogers Samuel N
Department of Medical Imaging, University of Arizona College of Medicine - Tucson, Tucson, USA.
Department of Pathology, University of Arizona College of Medicine - Tucson, Tucson, USA.
Cureus. 2024 Dec 23;16(12):e76289. doi: 10.7759/cureus.76289. eCollection 2024 Dec.
Plasmacytomas are rare monoclonal neoplastic plasma cell proliferations in soft tissue or bone, with clival plasmacytomas being extremely rare and occasionally presenting with light chain deposition disease (LCDD). While imaging findings for clival plasmacytomas have shown variable T2 signal characteristics, complete T2 signal loss has not been previously reported. We present a case of a 61-year-old female found to have a 1.9 cm expansile lytic lesion in the clivus on CT. MRI revealed intermediate T1 signal and near-complete T2 signal loss. Histopathology demonstrated kappa-restricted plasma cells with extracellular light chain deposition, while bone marrow biopsy showed 5-10% plasma cells without evidence of multiple myeloma. The patient was diagnosed with a solitary plasmacytoma of the clivus with associated LCDD and underwent endoscopic resection and radiotherapy, showing a favorable initial response at a seven-month follow-up. This case highlights the importance of considering plasmacytoma with associated LCDD for marked T2 hypointense, enhancing skull base lesions. The combination of plasmacytoma and LCDD may explain the unusual imaging characteristics, underscoring the need for comprehensive diagnostic approaches in patients presenting with unusually hypointense clival lesions.
浆细胞瘤是软组织或骨中罕见的单克隆性肿瘤性浆细胞增殖，而斜坡浆细胞瘤极为罕见，偶尔会伴发轻链沉积病（LCDD）。虽然斜坡浆细胞瘤的影像学表现显示出不同的T2信号特征，但此前尚未有完全T2信号消失的报道。我们报告一例61岁女性病例，CT检查发现其斜坡有一个1.9 cm的膨胀性溶骨性病变。MRI显示T1信号中等，T2信号近乎完全消失。组织病理学显示κ链受限的浆细胞伴有细胞外轻链沉积，而骨髓活检显示5%-10%的浆细胞，无多发性骨髓瘤证据。该患者被诊断为伴有相关LCDD的孤立性斜坡浆细胞瘤，并接受了内镜下切除和放疗，在7个月的随访中显示出良好的初始反应。该病例强调了对于明显T2低信号、强化的颅底病变，考虑伴有相关LCDD的浆细胞瘤的重要性。浆细胞瘤和LCDD的结合可能解释了这种不寻常的影像学特征，强调了对出现异常低信号斜坡病变的患者采用综合诊断方法的必要性。
