软组织转移瘤影像学诊断

Imaging diagnosis of metastatic tumor to soft tissue

目的：探讨软组织转移瘤的影像学表现特点。方法选择经病理证实的软组织转移瘤35例，分析其 CT 和MRI 表现特点。结果 CT 检查31例，其中平扫13例，增强扫描15例，平扫并增强扫描3例。 MRI 平扫3例。19个肌肉内转移瘤 CT 平扫表现为等密度或略低密度肿块，边界不清，密度均匀或不均匀，最大径1．2-25．3cm ；4例（21．52％）表现为弥漫性肌肉肿胀，密度均匀，与炎症相似；3例肿块内可见成簇的颗粒状或无定形钙化。9个皮下组织转移瘤 CT平扫表现为多发或单发结节状或团块状等或略低密度灶，最大径0．5-5．2cm ，边界清；2个表现为皮下组织内饼状软组织密度灶，边界不规则。 CT 增强扫描，病灶呈均匀或不均匀轻中度强化；其中7例（33．33％）呈环形强化，病灶中心不强化。3例 MRI 平扫表现为等长 T1，不均匀长 T2异常信号；2例边界清楚，1例边界不清。结论软组织转移瘤不罕见，在软组织肿瘤诊断中应注意鉴别。

Objective To explore imaging characters of soft tissue metastasis .Methods CT and MR imaging of 35 cases metastastic tumor of soft tissue confirmed pathologically were retrospectively analyzed .Results Of 35 cases ,13 cases were performed plain CT scan ,15 were performed enhanced scan ,and 3 were performed plain and contrast CT scan at the same time .19 intramusclular lesions were demonstrated iso‐or light low density with unclearly boundary on precontrast CT films ,the density of these lesions was homogeneous or inhomogeneious ,the maximum diameter of the lesions was 1.2 -25 .3 cm .4（21 .52% ）cases on CT scan displayed diffused swelling of muscles ,which were similar with inflammation ,and cluster or amorphous calcification was found in 3 cases .9 subcutaneous lesions were shown single or multiple nodular or lumpy lesions with iso‐or light low density ,whose maximum diameter of the lesions was 0 .5 - 5 .2 cm and their border was clear .2 subcutaneous lenticular lesions were shown iso‐density with irregular border .Lesions were manifested homogene‐ous or inhomogeneous light to moderate enhancement on post contrast CT pictures ,and 7（33 .33% ） cases showed margin‐al enhancement .3 lesions on MR pre‐contrast scan were demonstrated iso‐or light long T1 and uneven long T2 signal ,2 presented with clear border and 1 with unclear border .Conclusion Metastasis is not very rare and differential diagnosis should be done in diagnosis of soft tissue mass .