Wang Long, Tang Yongxiang, Yin Hongling, Hu Shuo
Department of Urology, The Third Xiangya Hospital, Central South University, Changsha, China.
Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, China.
Transl Androl Urol. 2021 Feb;10(2):991-996. doi: 10.21037/tau-20-1099.
Prostate specific membrane antigen (PSMA) is a transmembrane glycoprotein that was originally cloned in the membrane of prostate gland epithelial cells. It has been confirmed to be highly expressed in prostate cancer cells, and in some non-prostatic tissues, including the brain and some benign lesions. PSMA-based imaging has been extensively used for the assessment of prostate carcinoma. The high uptake of PSMA imaging in these non-prostate cancer lesions may lead to some misdiagnosis. It is of important clinical significance to explore the possible causes of high PSMA uptake in these lesions. Here, we present a case of a 77-year-old man with prostate carcinoma who underwent a whole-body F-PSMA-1007 positron emission tomography/computed tomography (PET/CT) scan for staging. The results of the scan showed intense tracer uptake in both the prostatic bed and in multiple subcutaneous lesions. The subcutaneous lesions were later found to be angiolipomas by histopathological examination. Immunohistochemistry demonstrated strong positive cytoplasmic PSMA staining in lesional prostate cancer cells in prostate carcinoma, and mild-to-moderate positive cytoplasmic capillary PSMA staining in angiolipoma fatty density nodules. Our case report therefore demonstrated that F-PSMA-1007 PET/CT uptake in multiple angiolipomas was caused by PSMA expression in capillaries, and further knowledge of PSMA expression in benign lesions may be critical to minimize false-positive findings with F-PSMA-1007 PET/CT imaging.
前列腺特异性膜抗原（PSMA）是一种跨膜糖蛋白，最初在前列腺腺上皮细胞膜中克隆得到。已证实其在前列腺癌细胞以及包括脑和一些良性病变在内的某些非前列腺组织中高表达。基于PSMA的成像已广泛用于前列腺癌的评估。这些非前列腺癌病变中PSMA成像的高摄取可能导致一些误诊。探究这些病变中PSMA高摄取的可能原因具有重要的临床意义。在此，我们报告一例77岁前列腺癌男性患者，其接受了全身F-PSMA-1007正电子发射断层扫描/计算机断层扫描（PET/CT）以进行分期。扫描结果显示前列腺床和多个皮下病变均有强烈的示踪剂摄取。后来经组织病理学检查发现皮下病变为血管脂肪瘤。免疫组织化学显示前列腺癌中病变前列腺癌细胞的细胞质PSMA染色呈强阳性，血管脂肪瘤脂肪密度结节中的细胞质毛细血管PSMA染色呈轻度至中度阳性。因此，我们的病例报告表明，多个血管脂肪瘤中F-PSMA-1007 PET/CT摄取是由毛细血管中的PSMA表达引起的，进一步了解良性病变中的PSMA表达对于最大限度减少F-PSMA-1007 PET/CT成像的假阳性结果可能至关重要。
