Li Ya, Hu Xianwen, Cai Jiong
Department of Nuclear Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, China.
Front Med (Lausanne). 2025 Jul 21;12:1613673. doi: 10.3389/fmed.2025.1613673. eCollection 2025.
Primary bladder diffuse large B-cell lymphoma (PB-DLBCL) is an exceedingly rare form of non-Hodgkin lymphoma, accounting for only 0.2% of all extranodal lymphomas. Here we report a case of PB-DLBCL in a woman presenting with hematuria. To determine the disease stage, an F-FDG PET/CT scan was performed after surgery. However, intense physiological F-FDG activity within the bladder lumen obscured potential lesions and concurrent CT imaging revealed suboptimal bladder distension limiting anatomical delineation. To address these limitations, 20 mg of intravenous furosemide was administered. Delayed imaging was performed 2 h after F-FDG injection (1 h after diuretic administration), revealing a focal hypermetabolic lesion in the left bladder wall. This metabolic pattern confirmed the diagnosis of PB-DLBCL, staged as IE according to the Ann Arbor classification. Following 4 cycles of R-CHOP chemotherapy, an F-FDG PET/CT scan was performed for treatment response assessment, confirming complete metabolic remission of the PB-DLBCL. This case highlights that dual-phase F-FDG PET/CT with intravenous diuretics can reduce bladder background activity and improve lesion visualization. Moreover, this approach holds significant clinical value in assisting with disease staging and evaluating treatment response.
原发性膀胱弥漫性大B细胞淋巴瘤（PB-DLBCL）是一种极其罕见的非霍奇金淋巴瘤，仅占所有结外淋巴瘤的0.2%。本文报告1例以血尿就诊的女性PB-DLBCL病例。为确定疾病分期，术后进行了F-FDG PET/CT扫描。然而，膀胱腔内强烈的生理性F-FDG活性掩盖了潜在病变，同时CT成像显示膀胱扩张欠佳，限制了解剖结构的勾勒。为解决这些局限性，静脉注射了20mg呋塞米。在注射F-FDG后2小时（利尿剂给药后1小时）进行延迟成像，显示膀胱左壁有一个局灶性高代谢病变。这种代谢模式证实了PB-DLBCL的诊断，根据Ann Arbor分类法分期为IE期。经过4个周期的R-CHOP化疗后，进行了F-FDG PET/CT扫描以评估治疗反应，证实PB-DLBCL完全代谢缓解。该病例表明，静脉注射利尿剂的双期F-FDG PET/CT可降低膀胱背景活性并改善病变可视化。此外，这种方法在协助疾病分期和评估治疗反应方面具有重要的临床价值。
