Fasih Najla, Prasad Shanbhogue Alampady K, Macdonald David B, Fraser-Hill Margaret A, Papadatos Demetrios, Kielar Ania Z, Doherty Geoffrey P, Walsh Cynthia, McInnes Matthew, Atri Mostafa
Department of Diagnostic Imaging, Ottawa Hospital, Ottawa, ON, Canada.
Radiographics. 2008 Nov-Dec;28(7):1931-48. doi: 10.1148/rg.287085095.
Uterine leiomyomas affect 20%-30% of women older than 35 years. Extrauterine leiomyomas are rarer, and they present a greater diagnostic challenge: These histologically benign tumors, which originate from smooth muscle cells, usually arise in the genitourinary tract (in the vulva, ovaries, urethra, and urinary bladder) but may arise in nearly any anatomic site. In addition, unusual growth patterns may be seen, including benign metastasizing leiomyoma, disseminated peritoneal leiomyomatosis, intravenous leiomyomatosis, parasitic leiomyoma, and retroperitoneal growth. In the presence of such a pattern, a synchronous uterine leiomyoma or a previous hysterectomy for removal of a primary uterine tumor may be indicative of the diagnosis. However, some extrauterine leiomyomas may mimic malignancies, and serious diagnostic errors may result. The most useful modalities for detecting extrauterine leiomyomas are ultrasonography, computed tomography, and magnetic resonance (MR) imaging. The superb contrast resolution and multiplanar capabilities of MR imaging make it particularly valuable for characterizing these tumors, which usually show low signal intensity similar to that of smooth muscle on T2-weighted images. The radiologist's recognition of this and other characteristic features may help steer the clinician toward timely, appropriate management and away from unnecessary, potentially harmful treatment.
子宫平滑肌瘤影响20%-30%的35岁以上女性。子宫外平滑肌瘤较为罕见，且诊断挑战更大：这些组织学上为良性的肿瘤起源于平滑肌细胞，通常发生于泌尿生殖道（外阴、卵巢、尿道和膀胱），但几乎可发生于任何解剖部位。此外，还可见异常生长模式，包括良性转移性平滑肌瘤、播散性腹膜平滑肌瘤病、静脉内平滑肌瘤病、寄生性平滑肌瘤和腹膜后生长。出现这种情况时，同时存在的子宫平滑肌瘤或既往因切除原发性子宫肿瘤而进行的子宫切除术可能提示诊断。然而，一些子宫外平滑肌瘤可能酷似恶性肿瘤，从而导致严重的诊断错误。检测子宫外平滑肌瘤最有用的方法是超声检查、计算机断层扫描和磁共振（MR）成像。MR成像出色的对比分辨率和多平面成像能力使其在这些肿瘤的特征性表现方面特别有价值，这些肿瘤在T2加权图像上通常表现为与平滑肌相似的低信号强度。放射科医生对这种及其他特征性表现的识别可能有助于指导临床医生进行及时、恰当的处理，避免不必要的、可能有害的治疗。
