Renal Neoformation: A Diagnosis to Consider

Renal granulomas related to suture material are rare and usually accidental findings in imagiological studies. A 12-year-old boy, followed-up after Anderson-Hynes pyeloplasty 7 years before, was submitted to an ultrasonography that described a solid nodular lesion, possibly in the dependence of the left kidney. Subsequently, magnetic resonance imaging was performed, which reported a lesion with non-specific features, suggesting neoformation with predominant fibrous peripheric component and myxomatous center. Percutaneous biopsy was morphologically compatible with chronic xanthogranulomatous inflammatory process. Anatomopathological examination of the surgical excised lesion described histiocytic cells with frequent participation of foreign body type giant cells and granulomatous reaction in relation to exogenous suture-like material. He remains asymptomatic since then. Foreign body granulomatous pseudotumors are difficult to diagnose regarding the absence of specific imagiological features distinctive from neoplasms, requiring histological examination to confirm the diagnosis.