Michaelis-Gutmann body

Michaelis-Gutmann bodies (M-G bodies) are concentrically layered basophilic inclusions found in the urinary tract. They are 2 to 10 μm in diameter, and are thought to represent remnants of phagosomes mineralized by iron and calcium deposits.

M-G bodies are a pathognomonic feature of malakoplakia, an inflammatory condition that affects the genitourinary tract. They were discovered in 1902 by Leonor Michaelis and Carl Gutmann.