腰大肌肌内黏液瘤1例并文献复习

Intramuscular myxoma of psoas major muscle:a case report and literature review

目的探讨腰大肌肌内黏液瘤的临床表现、病理特征和影像表现,以提高对该病的影像诊断和鉴别诊断能力。方法回顾性分析1例经手术病理证实的腰大肌肌内黏液瘤病人的临床病理特征以及CT和MRI表现,并复习相关文献。结果 CT显示右侧腰大肌内巨大卵圆形肿块影,边界清晰,呈水样均匀密度,邻近肌肉受压,邻近腰椎未见明显骨质破坏。MRI示右侧腰大肌内边界清晰卵圆形异常信号影,T1WI呈低信号,T2WI呈高信号,病灶内可见多发分隔影。病灶边缘可见包膜影,病灶下极包膜欠完整,病变下极向邻近肌肉浸润,病灶邻近肌肉受压。病理组织学诊断为肌内黏液瘤。免疫组化显示波形蛋白(Vimentin)、平滑肌肌动蛋白(SAM)、CD34呈阳性。结论腰大肌肌内黏液瘤罕见,其临床和影像表现无明显特异性,确诊需依赖于病理组织学检查。

Objective To explore the clinical manifestations,pathological features,and imaging findings of intramuscular myxoma of psoas major muscle in order to enrich our knowledge of imaging diagnosis and differential diagnosis of intramuscular myxoma of psoas major muscle. Methods The clinical,pathological,and imaging data of a patient with confirmed intramuscular myxoma of psoas major muscle by pathology were retrospectively analyzed and literature was reviewed. Results CT showed a large oval mass with clear boundary in the right psoas major muscle. The density of the lesion was uniform and showed as watery density. Adjacent muscle of the lesion was compressed. There was no obvious bone destruction in the adjacent lumbar spine. MRI showed an oval mass with clear boundary in the right psoas major muscle. The lesion showed low signal on T1WI,high signal on T2WI,and multiple separates in the lesion. There was a capsule surrounding the mass. The capsule at the lower pole of the lesion was incomplete. The lower pole of the lesion infiltrated into the adjacent muscle. Compression of adjacent muscles also could be seen on MRI scan. Histopathology diagnosis was intramuscular myxoma. Immunohistochemistry showed that the Vimentin,smooth muscle actin (SAM) and CD34 were positive. Conclusion Intramuscular myxoma of the psoas major muscle is rare,and its clinical and imaging manifestations are not specific. The diagnosis depends on pathological examination.