Four stages of neurocysticercosis

In the brain parenchyma, the cysticercus larva passes through 4 distinct stages. (Left upper) In the “vesicular stage,” the larva transforms into a cyst filled with clear fluid. Vesicular cysts are viable. (Right upper) In the “colloidal stage,” inflammatory changes develop in the cyst wall and surrounding brain parenchyma. This stage of larva is often referred to as cysticercal granuloma. (Left lower) Progressive mineralization of cystic fluid and disintegration of scolex leads to a “granular-nodular stage.” (Right upper) Ultimately, the whole cyst is completely mineralized resulting in a “calcific stage.” (Right lower) (Contributed by Dr. Ravindra Kumar Garg.)