Department of Radiology, Keck School of Medicine of USC, Los Angeles, CA, USA.
Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
Abdom Radiol (NY). 2023 May;48(5):1820-1830. doi: 10.1007/s00261-022-03662-7. Epub 2022 Sep 9.
Perinephric myxoid pseudotumor of fat (PMPF) is an unusual clinical entity with few prior imaging case reports. We report a multimodality imaging case series of PMPF, consisting of four cases seen in our department with both imaging studies and histopathologic confirmation. Three of the four patients had a history of advanced non-neoplastic renal disease. The perirenal masses in these cases varied in size and appearance. Some lesions resembled cysts or contained macroscopic fat. Enhancement was equivocal on CT, but prominent in one case on MRI and in another on contrast-enhanced ultrasound. Although not known to be malignant, PMPF may be confused for a cyst, liposarcoma, or hypovascular solid neoplasm on imaging. The dominant mass was resected in two cases because of concern for malignancy, while percutaneous CT-guided biopsy was performed in the other two. Mouse double minute 2 (MDM2) gene amplification by fluorescence in situ hybridization (FISH) was negative in all four cases, excluding well-differentiated liposarcoma. Radiologists should be familiar with PMPF to provide appropriate guidance on clinical management.
肾周黏液样假瘤性脂肪肿瘤（PMPF）是一种不常见的临床实体，之前仅有少数影像学病例报告。我们报告了一个 PMPF 的多模态影像学病例系列，包括在我们科室中观察到的四个病例，这些病例既有影像学研究，也有组织病理学证实。这四个患者中的三个有晚期非肿瘤性肾脏疾病的病史。这些病例的肾周肿块大小和外观各异。一些病变类似于囊肿或含有肉眼可见的脂肪。CT 增强扫描结果不确定，但在一个病例的 MRI 上和另一个病例的对比增强超声上表现明显。尽管 PMPF 不被认为是恶性的，但在影像学上可能会被误诊为囊肿、脂肪肉瘤或低血供实性肿瘤。由于担心恶性肿瘤，两个病例中进行了主要肿块切除术，而另外两个病例则进行了经皮 CT 引导下活检。所有四个病例的荧光原位杂交（FISH）均未发现鼠双微体 2 基因（MDM2）扩增，排除了分化良好的脂肪肉瘤。放射科医生应该熟悉 PMPF，以便为临床管理提供适当的指导。
