【双语病例】下肢未分化多形性肉瘤一例影像表现

16 8月

History

An 88-year-old man presents with a new, firm, painless right thigh mass. He has experienced a 10-lb weight loss in the last two months.

88岁男性,发现右大腿质硬、无痛性肿块。近两月体重减轻约10磅。

【双语病例】下肢未分化多形性肉瘤一例影像表现

【双语病例】下肢未分化多形性肉瘤一例影像表现

【双语病例】下肢未分化多形性肉瘤一例影像表现

1.What is the small focus of calcification seen on the axial image?

横断位所见斑点状钙化灶考虑是什么性质?

Calcific tendinopathy 肌腱钙化

Atherosclerotic disease 动脉硬化性疾病

Calcification within a soft-tissue mass 软组织肿块内钙化

Foreign body 异物

MR Images

Axial T1-weighted image:

【双语病例】下肢未分化多形性肉瘤一例影像表现

axial T1-weighted image with fat saturation:

【双语病例】下肢未分化多形性肉瘤一例影像表现

axial postcontrast subtraction(减影) T1-weighted image:

【双语病例】下肢未分化多形性肉瘤一例影像表现

axial short tau inversion-recovery (STIR) images:

【双语病例】下肢未分化多形性肉瘤一例影像表现

coronal short tau inversion-recovery (STIR) images:

【双语病例】下肢未分化多形性肉瘤一例影像表现

2.There is invasion of the right femur.

右股骨受侵

True

False

3.The mass is mostly cystic.

肿块以囊性为主

True

False

4.The mass is mostly solid.

肿块以实性为主

True

False

5.What is the etiology of the mass?

肿块的病因是什么?

Inflammatory 感染

Traumatic 外伤

Neoplastic 肿瘤

Congenital 先天性

【双语病例】下肢未分化多形性肉瘤一例影像表现
选择题答案:

  1. Atherosclerotic disease

  2. False

  3. False

  4. True

  5. Neoplastic

Findings

  • CT: Unenhanced CT images demonstrate a large, well-circumscribed, mildly heterogeneous soft-tissue mass. The mass abuts the right femur without definite cortical involvement. Calcification is seen within the superficial femoral artery. There is no calcification within the mass.

    CT:CT平扫可见较大软组织肿块,边界清楚,密度不均匀。肿块与股骨相邻,无明显骨皮质受侵。股浅动脉可见钙化。肿块内无明显钙化。

  • MRI: MR images demonstrate a large well-circumscribed, heterogeneous enhancing mass in the posteromedial right thigh. There are central areas of hemorrhage and necrosis. The medial compartment muscles are not well-visualized. There is mass effect on the posterior compartment muscles, with invasion not excluded. The superficial femoral artery is seen anterior to the mass. The cortex of the right femur abuts the mass, without definite erosion or invasion.

    MRI:右大腿后内侧软组织肿块,边界清楚,增强扫描不均匀强化。大腿后部肌肉受压,但无明显受侵。股浅动脉位于肿块前方。肿块与股骨相邻,骨皮质无明显受侵。

Differential Diagnosis

  • Undifferentiated pleomorphic sarcoma 未分化多形性肉瘤

  • Pleomorphic liposarcoma 多形性脂肪肉瘤

  • Dedifferentiated liposarcoma 未分化脂肪肉瘤

  • Pleomorphic leiomyosarcoma 多形性平滑肌肉瘤

  • Pleomorphic rhabdomyosarcoma 多形性横纹肌肉瘤

  • Traumatic hematoma 外伤性血肿

  • Myositis ossificans 骨化性肌炎

Diagnosis

Undifferentiated pleomorphic sarcoma

未分化多形性肉瘤

Discussion

Undifferentiated pleomorphic sarcoma, also known as malignant fibrous histiocytoma, is one of the most common soft-tissue sarcomas of adult age. It can occur in both soft tissue or bone, and given its undifferentiated mesenchymal histology, it may contain a variety of cells, tissues, and growth patterns. The two most common histologic patterns are the storiform-pleomorphic subtype (50% to 60%) and myxoid subtype (25%).

未分化多形性肉瘤又称为恶性纤维组织细胞瘤,是成年人最常见的软组织肉瘤,可发生于软组织或骨骼。由于其组织学的未分化性,可包含多种细胞、组织和生长方式。最常见的两种组织学类型是席纹状-多形性型(50%-60%)和粘液型(25%)

Most pleomorphic sarcomas develop spontaneously, though prior radiation increases risk at the site of exposure. They may develop anywhere; however, pleomorphic sarcomas most commonly occur in the extremities, particularly the lower extremities (50%). They usually develop in late adult life, peaking in the sixth and seventh decades, and present as a large, painless, growing mass.

尽管辐射可增加曝光部位的发病几率,但大部分的多形性肉瘤为自发。可发生于任何部位,最常见于四肢,特别是下肢(50%)。该病常发生于老年人,尤其是60-70岁,一般表现为大的无痛性肿块,生长较迅速。

Radiographically, they appear as large soft-tissue masses, typically adjacent to long-bone diaphyses in the extremities. On CT, the mass may contain areas of decreased attenuation reflecting myxomatous tissue, hemorrhage, and/or necrosis. CT can be useful to detect internal calcification and adjacent osseous cortical erosion or invasion. MR characteristics are nonspecific, usually demonstrating intermediate signal on T1-weighted images and heterogeneous high signal on T2-weighted images. Myxoid components may demonstrate areas of low T1- and high T2-weighted signal intensity. Enhancement of solid components is seen. Approximately 5% of pleomorphic sarcomas may be extensively hemorrhagic and mimic a hematoma. Thus, underlying malignancy must be excluded in patients presenting with spontaneous soft-tissue hemorrhage.

影像典型表现为四肢长骨骨干旁软组织肿块。CT上肿块常包含低衰减区,对应粘液组织、出血、和/或坏死。CT有助于显示肿瘤内的钙化及邻近骨骼的受压侵蚀。

MR上表现没有明显特异性,常表现为T1WI中等信号,T2WI呈不均匀高信号。粘液成分T1WI低信号、T2WI高信号。增强扫描实性部分强化。大约5%左右的多形性肉瘤内可见弥漫性出血,类似于血肿。因此软组织内自发血肿,有可能是良性肿瘤。

Treatment involves wide local excision and possibly neoadjuvant chemotherapy and/or adjuvant chemotherapy and radiation therapy. Overall prognosis is unfavorable. Local recurrence is not uncommon and often multiple. Metastatic disease most often involves the lungs (90%), lymph nodes, liver, and bone.

治疗方法包括局部广泛切除术、新辅助化疗、和/或辅助化疗和放射治疗,预后一般不会。常可见局部复发,且一般为多发。转移瘤多发生于肺(90%)、淋巴结、肝脏和骨骼。

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