The sago spleen and lardaceous spleen are conditions seen in-

Amyloidosis of SpleenAmyloid deposition in the spleen, for some unknown reasons, may have one of the following two patterns:1. SAGO SPLEEN. The splenomegaly is not marked and cut surface shows characteristic translucent pale and waxy nodules resembling sago grains and hence the name.Microscopically, the amyloid deposits begin in the walls of the aerioles of the white pulp and may subsequently replace the follicles.2. LARDACEOUS SPLEEN. There is generally moderate to marked splenomegaly (weight up to 1 kg). Cut surface of the spleen shows map-like areas of amyloid (lardaceous-lard-like; lard means fat of pigs)Microscopically, the deposits involve the walls of splenic sinuses and the small aeries and in the connective tissue of the red pulp. Confirmation is by seeing Congophilia in Congo Red staining and demonstration of apple-green birefringence under polarising microscopy in the corresponding positive areas. HARSH MOHAN Textbook of pathology 6th edition pg no 90