Increased rouleaux formation in the peripheral blood is a characteristic feature of -
Rouleaux in a Peripheral Smear, Multiple Myeloma. Rouleaux are linear aggregates of red blood cells that form in the presence of increased plasma proteins. This phenomenon differs from agglutination, in which red blood cells form grape like clusters due to the presence of antibodies bound to their surfaces Ref Davidson 23rd edition pg 976
Multiple myeloma
Non-Hodgmin's lymphoma
Tuberculosis
Malaria
Miscellaneous