Malakoplakia: Rare Disorder with No Significant Racial Prevalence

Introduction: Malakoplakia is a rare acquired granulomatous inflammatory condition. Microscopically it is characterized by sheets of histiocytes with abundant eosinophilic granular cytoplasm (known as von Hansemann cells) with intracytoplasmic rounded concentric basophilic inclusions (Michelis-Guttmann bodies). We reviewed all cases of malakoplakia diagnosed at our institution in the past 15 years, including clinical, macroscopic, and microscopic features as well as treatment and prognosis. Methods: Gross and microscopic features of cases diagnosed as malakoplakia from 2005 to 2019 at our institution were reviewed. Clinical history, including sites of involvement, clinical presentation, imaging, past medical history, treatment, follow-up and prognosis, as well as demographic characteristics were obtained. Results: Eighteen surgical pathology cases of malakoplakia were identified. Most cases occurred in female (14/18, 77.8%) and all in adults (median age 48.5 years; range 31 - 87). Half of the patients were Caucasian, 44% African American and 6% were reported as “other” race. One third (6/18) of patients presented with a mass-like lesion on imaging or endoscopic studies. As to site of lesion, 61.1% (11/18) involved GU tract, 27.8% (5/18) gastrointestinal (GI) tract, 5.6% (1/18) liver, and 5.6% (1/18) vagina. 38.9% of patients (7/18) had antibiotics treatment upon diagnosis. Conclusion: Malakoplakia is a rare disorder occurring in a wide age range, more commonly in females, with no significant racial prevalence. While the GU and GI tracts are the most common sites, other anatomic locations can be involved. Accurate diagnosis and appropriate treatment are important to avoid recurrence.