Michaelis gutmann bodies are found in -

This is a rare condition most frequently found in the urinary bladder but can occur in the ureters, kidney, testis, and prostate and occasionally in the gut. Etiology unknown may be due to persistent chronic inflammation with the defective phagocytic process by macrophages. Common in immunosuppressed patients and in transplant recipients. Microscopically plaques are composed of foamy macrophages, occasional giant cells, and lymphocytes. These macrophages have granular PAS positive cytoplasm and some contain cytoplasmic laminated concretions of calcium phosphate called 'Michaelis -Gutman bodies'. This ultrastructurally represents lysosomes filled with paly digested debris of bacteria phagocytosed by the macrophages which have not been digested fully by them due to defective phagocytosis. Ref: Textbook of pathology Harsh Mohan 7th edition, pg no:686