Cutaneous malakoplakia presenting as a groin swelling and graft failure

Abstract

Malakoplakia (from the Greek malakos, 'soft' and plakos 'plaque') is a granulomatous inflammatory condition, commonly presenting as a plaque in the genitourinary system, but has been shown to affect a wide variety of structures including the skin. Presentation is varied and a high degree of clinical suspicion is needed to make a diagnosis. We report a case of cutaneous malakoplakia presenting as an inguinal swelling in a 48-year-old kidney transplant patient with temporally associated graft dysfunction. New groin swelling in an immunosuppressed patient often prompts investigation centred on a malignant cause. While this is often appropriate, less common infectious and inflammatory causes should be considered. This case highlights the importance of thorough workup and investigation, including histopathology, in immunosuppressed cohorts and acts as a reminder that less common and more complex diagnoses warrant consideration in this group.

Keywords: infectious diseases; pathology; renal transplantation.

Figure 1

Sample MRI images of the lesion, highlighted in red. (A) T1-weighted MRI of the scrotum demonstrating lesion. (B) Diffusion-weighted (DW) MRI of scrotum (C) Fused T1/DW MRI of scrotum (D) T1-weighted MRI of inguinal canal demonstrating lesion (E) DW MRI of inguinal canal (F) Fused T1/DW MRI of inguinal canal.

Figure 2

Sample core biopsy images on H&E preparation (A) sheets of eosinophilic/pink cells are seen infiltrating adipose tissues (large clear spaces) and there are numerous grey/basophilic circular inclusions within the cytoplasm (black arrows) representing Michaelis-Gutmann bodies. As these inclusions contain calcium, they are highlighted on the Von Kossa stain (B) as black dots. The cells are confirmed as macrophages (histiocytes) by positive expression of CD68 by immunocytochemistry (C). The red ruler marks 100 microns.