Renal malakoplakia mimicking a malignancy and diagnosed by fine‐needle aspiration: A case report

Abstract

Malakoplakia is a rare, granulomatous disease that affects a wide variety of organs and can have a clinical and radiographic presentation resembling that of malignancy. The genitourinary tract is the most commonly involved site. There are scant reported cases presenting as a locally advanced renal mass and even rarer, diagnosed by fine-needle aspiration (FNA) cytology. We report clinical, imaging, cytologic, and histological findings of an interesting case of malakoplakia initially diagnosed by FNA cytology. We also briefly review the literature and emphasize the importance of recognizing this entity when encountered in an aspirate material, which can help mitigate the diagnostic confusion of malakoplakia for clinicians.

Prostatic malakoplakia: clinicopathological assessment of a multi‐institutional series of 49 patients

“…MP has a predilection for patients with baseline immunosuppression and can be frankly symptomatic or clinically silent and diagnosed incidentally during the evaluation of other medical conditions 8 . Symptomatology is highly dependent upon the organ system involved, but presentation as a mass mimicking malignancy has been well described at multiple anatomical sites 9–13 . Although local recurrences may occur, MP usually follows an indolent clinical course, with good response to a combination of antibiotic therapy, surgical resection and/or reduction of immunosuppression 14,15 .…”

“…8 Symptomatology is highly dependent upon the organ system involved, but presentation as a mass mimicking malignancy has been well described at multiple anatomical sites. [9][10][11][12][13] Although local recurrences may occur, MP usually follows an indolent clinical course, with good response to a combination of antibiotic therapy, surgical resection and/or reduction of immunosuppression. 14,15 However, exceptionally rare aggressive cases with fatal outcomes have been documented previously, mainly prior to the availability of newer antimicrobials.…”

A very complicated UTI: malakoplakia following E. coli urinary tract infection

“…Histologically, this appears as macrophage infiltrates with cytoplasmic inclusions known as Michaelis-Gutmann bodies, the pathognomonic finding in malakoplakia [ 1 , 5 ]. CD68 and CD163 immunostains confirm the histiocyte lineage, and kidney biopsy typically shows interstitial inflammation with fibrosis and tubular atrophy [ 6 , 7 ]. Treatment consists of a prolonged course of antibiotics with high intracellular penetration; if medical management is unsuccessful, surgical resection may be required.…”