Renal malakoplakia presenting as a renal mass in a 55-year-old man: a case report

• Published in: Journal of medical case reports 2012-11, Vol.6 (1), p.379-379, Article 379
• Main Authors: Abolhasani, Maryam, Jafari, Azam Mohammad, Asgari, Mojgan, Salimi, Hormoz
• Format: Article
• Language: English
• Subjects: Care and treatment; Case Report; Case studies; Diagnosis; Health aspects; Kidney diseases; Risk factors; Urinary tract infections
• ISSN: 1752-1947; 1752-1947
• DOI: 10.1186/1752-1947-6-379

Malakoplakia is an uncommon chronic inflammatory condition that has a gross and microscopic appearance resembling that of xanthogranulomatous pyelonephritis. It is characterized by distinctive Michaelis-Gutmann bodies. Malakoplakia can affect any organ system but genitourinary tract involvement is the most common, particularly in immunocompromised individuals. Very rare cases have been reported to present as a unifocal lesion mimicking a renal tumor. We report a case of renal malakoplakia in a 55-year-old Iranian man with a past history of recurrent urinary tract infections who presented with left flank pain. An ultrasound study showed a large solid left renal mass, and he underwent a left radical nephrectomy with a clinical diagnosis of a renal tumor. Pathology slides revealed the diffuse infiltration of sheets of Periodic Acid Schiff-positive histiocytes in his renal parenchyma; these cells showed strong immunoreactivity for CD 68. The final diagnosis was renal malakoplakia. Renal malakoplakia must be kept in mind for patients presenting with a renal mass and a history of long-term recurrent renal infections or renal failure. The large, rapidly growing nodules of malakoplakia may mimic renal cell carcinoma in imaging studies. In these cases, a true cut needle biopsy may help the correct diagnosis and prevent unnecessary surgery.