[wemedico]

A 65 years old man was brought to the hospital who have had a low grade intermittent fever of unknown origin and unconscious weight loss for last three months. on physical examination hepatosplenomegaly was found. Auxiliary examination reveals normal chest x-ray, blood dyscrasia with pancytopenia. The patient shows negative tuberculin test. On biopsy of liver and bone marrow multiple granuloma like structure was found and depressed marrow function was elicited. what is the most likely diagnosis ???