Granulomatosis with polyangiitis presenting as a solitary renal mass: A case report with imaging and literature review

• Main Authors: Takahiro Yamamoto, MD, Kyohei Tkahata, MD, Seiji Kamei, MD, Misawo Ishikawa, MD, Daisuke Matsumoto, MD, Kojiro Suzuki, MD
• Format: Article
• Language: English
• Published: Elsevier 2021-03-01
• Series: Radiology Case Reports
• Subjects: Granulomatosis with polyangiitis; Hypovascular renal mass; CT; MRI
• Online Access: http://www.sciencedirect.com/science/article/pii/S1930043321000121

Granulomatosis with polyangiitis (GPA) manifests as necrotizing granulomatous inflammatory masses in the nasal cavity, paranasal sinuses, and lungs. However, a mass in the kidney is extremely rare. We herein report a case of GPA that presented as a solitary mass in the left kidney. The patient was a man in his 60s. A 2.5-cm solitary mass was incidentally discovered in the left kidney at another hospital and was followed-up. Eight months later, the mass had enlarged, and the patient visited our hospital for further examination and treatment. The mass was hypovascular, with unclear margins on contrast-enhanced computed tomography (CT). The signal of the mass was nonuniform and iso- to slightly hypo-intense on T2-weighted and diffusion-weighted magnetic resonance imaging (MRI). Enlarged para-aortic lymph nodes were also detected on the CT and MRI. Based on imaging, malignant tumors were suspected, and nephrectomy was performed. The pathological diagnosis was GPA. We performed a literature review of this rare renal manifestation and present a summary of reported imaging findings. If a hypovascular renal mass with an unclear margin can be found in those with GPA, unnecessary operations may be avoided by actively promoting renal biopsy.