Tang Yongxiang, Yang Jinhui, Zhou Chuanchi, Li Jian, Hu Shuo
Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, China.
Department of Urology, Xiangya Hospital, Central South University, Changsha, China.
Transl Androl Urol. 2022 Apr;11(4):561-566. doi: 10.21037/tau-21-1068.
Xanthogranulomatous prostatitis (XGP) is a rare disorder of the prostate. It presents as a hard fixed nodule on digital rectal examination (DRE), and may cause obstructive urinary symptoms and elevated serum prostate-specific antigen (PSA) levels, therefore mimicking prostate cancer (PCa) clinically and biochemically. Radiological features of XGP overlap with those of PCa, and the 2 conditions cannot be distinguished by pelvic multiparametric magnetic resonance imaging (mpMRI). Ga-labelled prostate-specific membrane antigen (Ga-PSMA) with positron emission tomography/computed tomography (PET/CT) has shown its potential in the initial diagnosis and staging of PCa; however, the imaging characteristics of XGP on Ga-PSMA PET/CT have yet to be reported.
We report the case of a 56-year-old man who had slowly progressing dysuria for 10 years, which was significantly worse for 1 week, and a PSA level of 49.19 ng/L. Ultrasound revealed a hypoechoic lesion in the left periphery of the prostate, which was hypointense with capsular irregularity on axial T2-weighted imaging (T2WI), hyperintense on the diffusion weighted imaging (DWI), and hypointense on the apparent diffusion coefficient (ADC) maps resulting in a Prostate Imaging-Reporting and Data System (PI-RADS) score of 5. The patient was highly suspected of having high-risk PCa and underwent a Ga-PSMA PET/CT for staging. The PET/CT images showed no PSMA uptake in the involved region. Considering that a small proportion of cases of PCa do not express PSMA, a subsequent targeted biopsy was performed, guided by mpMRI. Histopathological examination showed a large number of foamy macrophages in the neutrophile granulocyte infiltrate, and XGP was finally diagnosed. After treatment with antibiotic levofloxacin, the patient's PSA returned to normal, and his dysuria symptoms had disappeared at the 2-month follow-up.
Non-uptake of PSMA in a lesion may still provide information for a diagnosis by exclusion or regular follow-up checks in patients that are highly suspected to have PCa in clinic or on mpMRI.
黄色肉芽肿性前列腺炎（XGP）是一种罕见的前列腺疾病。它在直肠指检（DRE）时表现为坚硬固定的结节，可能导致梗阻性尿路症状和血清前列腺特异性抗原（PSA）水平升高，因此在临床和生化方面与前列腺癌（PCa）相似。XGP的放射学特征与PCa重叠，这两种情况无法通过盆腔多参数磁共振成像（mpMRI）区分。镓标记的前列腺特异性膜抗原（Ga-PSMA）正电子发射断层扫描/计算机断层扫描（PET/CT）已显示出其在PCa初始诊断和分期中的潜力；然而，XGP在Ga-PSMA PET/CT上的成像特征尚未见报道。
我们报告了一例56岁男性患者，其排尿困难缓慢进展10年，近1周明显加重，PSA水平为49.19 ng/L。超声显示前列腺左外周有一个低回声病变，在轴位T2加权成像（T2WI）上呈低信号且包膜不规则，在扩散加权成像（DWI）上呈高信号，在表观扩散系数（ADC）图上呈低信号，前列腺影像报告和数据系统（PI-RADS）评分为5分。该患者高度怀疑患有高危PCa，并接受了Ga-PSMA PET/CT检查以进行分期。PET/CT图像显示受累区域无PSMA摄取。考虑到一小部分PCa病例不表达PSMA，随后在mpMRI引导下进行了靶向活检。组织病理学检查显示中性粒细胞浸润中有大量泡沫状巨噬细胞，最终诊断为XGP。使用抗生素左氧氟沙星治疗后，患者的PSA恢复正常，在2个月的随访中排尿困难症状消失。
病变中PSMA无摄取仍可为临床或mpMRI高度怀疑患有PCa的患者提供排除诊断或定期随访检查的信息。
