肾上腺海绵状血管瘤的CT及MR表现

The CT and MR findings of adrenal cavernous hemangiomas

目的探讨肾上腺海绵状血管瘤的CT及MR表现,提高对肾上腺海绵状血管瘤的认识。方法回顾性分析5例经手术病理证实的肾上腺海绵状血管瘤的CT及MR表现,并复习相关文献,探讨其影像表现特点。结果 5例肾上腺海绵状血管瘤,位于左侧3例,右侧2例,5例均为单发,圆形或类圆形,边缘清楚,最大径1.7~15.0cm。肿瘤内含有钙化的3例,肿瘤中央区域出血、囊变、坏死或纤维化的5例,肿瘤内见成熟脂肪的3例(位于肿瘤边缘的脂肪在重建图像上与肿瘤外脂肪相连,推测可能是肿瘤将其外面的脂肪卷入肿瘤内,故称"肿瘤外脂肪卷入征"),强化方式均为动脉期肿瘤边缘结节状明显强化,随时间延长强化范围扩大,但中央区域始终未见明显强化或轻度强化。结论肾上腺海绵状血管瘤CT及MR表现有一定的特征性,肿瘤内多伴有钙化,增强后肿瘤边缘结节状明显强化,随时间延长强化范围扩大,"肿瘤外脂肪卷入征"是笔者发现的新征象,多在肿瘤较大时出现,可能为肾上腺海绵状血管瘤的另一影像学特点,对诊断及鉴别诊断有很大帮助,但有待更多病例证实。

Objective By discussing the CT and MRI findings of adrenal cavernous hemangiomas to raise the awareness of adrenal cavernous hemangiomas.Methods CT and MRI findings were retrospectively analyzed in 5 cases of adrenal cavernous hemangiomas confirmed by operation and pathology and the related literatures were reviewed to discuss the imaging features.ResultsIn 5 cases of adrenal cavernous hemangiomas, 3 were located in the left adrenal gland and 2 in right adrenal gland.Every lesion was single, round or roundlike mass with sharp outline.The size range was 1.7~15.0 cm.Calcifications were found in 3 cases.Hemorrhage, cystic change, necrosis and fibrosis in central part of the tumors were found in 5 cases.Mature fat was found in 3 cases （fat in marginal part of the tumors was continuous with the outside fat in reconstructed images.The speculation was the outside fat may be involved in the mass.＂The sigh of involved outside fat＂ was so called）.5 cases displayed nodosity obvious enhancement in arterial phase and filling in with time, but the central part showed no enhancement or mild enhancement.Conclusion Adrenal cavernous hemangiomas have certain characteristics on CT and MR.Calcifications can be often found and the mass displayed nodosity obvious enhancement in arterial phase and filling in with time.The sigh of involved outside fat is a new sign that is found by the author, often occurred in larger tumor, which may be another imaging feature of adrenal cavernous hemangiomas and is helpful for the diagnosis and differential diagnosis, but needs more cases to be confirmed.