Renal parenchymal malakoplakia: an unusual cause of unilateral, diffuse renal enlargement

Renal parenchymal malakoplakia is usually described as a multi- or unifocal process. We report an unusual case presenting with unilateral diffuse renal enlargement consistent with an early stage in the evolution of this disease. Malakoplakia, derived from the Greek words 'malakos' (soft) and 'plakos' (plaque), is an unusual chronic inflammatory disorder most commonly involving the urinary bladder and rarely affecting the renal parenchyma. More than 400 cases of renal malakoplakia have been reported in the literature since the condition was first described. The clinical presentation and imaging findings are non-specific, and histopathological examination is necessary to differentiate the disorder from more common entities. The case reported here is unusual in its manifestation as unilateral, homogeneous, diffuse nephromegaly, with no discrete lesions demonstrated on CT or ultrasound examination. Review of the literature supports that this is a result of imaging at an early stage of the disease. Renal biopsy is, however, essential to establish a definitive diagnosis. Copyright (2002) Blackwell Science Pty Ltd