San Antonio Uniformed Services Health Education Consortium, 3551 Roger Brooke Dr., Fort Sam Houston, TX, 78234, USA.
Department of Neuroradiology, University of Texas Southwestern, Dallas, TX, USA.
Skeletal Radiol. 2020 Dec;49(12):2087-2093. doi: 10.1007/s00256-020-03514-9. Epub 2020 Jun 19.
Extramedullary plasmacytomas are rare neoplasms arising from proliferations of monoclonal plasma cells. In primary form, these malignancies occur without other sites of plasma cell disease. Secondary extramedullary plasmacytomas occur in association with multiple myeloma and may be discovered during initial intramedullary disease or may occur during multiple myeloma relapse. In very rare instances, secondary extramedullary plasmacytomas have multifocal skeletal muscle involvement. We present a case of multifocal skeletal muscle plasmacytomas in a 58-year-old man with shoulder-reduced range of motion, pain, and a history of previously treated multiple myeloma. To our knowledge, the patient's unique relapse presentation of torso and shoulder soft tissue masses and the vast extent of skeletal muscle involvement are unique to cases in the current literature. This case also has MRI findings of a muscular plasmacytoma with internal hemorrhage which has not been previously reported. This case report will review imaging features and clinical presentations of intramuscular extramedullary plasmacytomas. Since imaging surveillance for multiple myeloma relapse is commonly performed, radiologists should be aware of these uncommon relapsing features including multifocal intramuscular masses which may contain internal hemorrhage.
髓外浆细胞瘤是一种罕见的肿瘤，由单克隆浆细胞增殖引起。在原发性浆细胞瘤中，这些恶性肿瘤发生于无浆细胞病的其他部位。继发性髓外浆细胞瘤发生于多发性骨髓瘤，并可能在初始髓内疾病时被发现，或在多发性骨髓瘤复发时发生。在极少数情况下，继发性髓外浆细胞瘤有多处骨骼肌受累。我们报告一例 58 岁男性患者，表现为肩部活动范围减小、疼痛，并有先前治疗过的多发性骨髓瘤病史。据我们所知，该患者独特的复发表现为躯干和肩部软组织肿块，以及广泛的骨骼肌受累，在目前的文献中是独一无二的。该病例还具有 MRI 表现为肌肉浆细胞瘤伴内部出血，这在以前的报告中尚未报道过。本病例报告将回顾肌肉内髓外浆细胞瘤的影像学特征和临床表现。由于多发性骨髓瘤复发的影像学监测通常是常规进行的，放射科医生应该了解这些罕见的复发特征，包括可能包含内部出血的多发性肌内肿块。
