Reactive lymphoid hyperplasia (RLH) is a rare benign lymphoproliferative disorder that rarely involves the kidney and has not been reported in association with regional lymphadenopathy.
A 70-year-old woman was incidentally found to have a left renal mass. Contrast-enhanced computed tomography revealed a 20-mm enhancing renal lesion with enlarged hilar lymph nodes, leading to a preoperative diagnosis of renal cell carcinoma with nodal metastasis (cT1aN1M0). Open radical nephrectomy with regional lymphadenectomy was performed. Histopathological analyses established a diagnosis of reactive lymphoid hyperplasia. No additional treatment was administered, and the patient has remained free of recurrence for 3 months.
We report the first case of RLH accompanied by regional lymph node enlargement. Because RLH can closely mimic renal cell carcinoma on imaging, it should be considered in the differential diagnosis of renal masses when the clinical presentation is inconsistent with typical renal cell carcinoma.
IJU case reports. 2026 Mar 08*** epublish ***
Shunki Nakagawa, Yasutomo Nakai, Yujiro Hayashi, Yutaka Kurahashi, Shu Okamoto, Yuichiro Nakamura, Norihiko Kawamura, Akira Nagahara, Masashi Nakayama, Kazuo Nishimura
Department of Urology Osaka International Cancer Institute Osaka City Japan.