Lymphohistiocytic T-cell Lymphoma and Peripheral T-cell Lymphoma Associated with Haemophagocytic Syndrome: Two Recently Recognized Entities Which Mimic Malignant Histiocytosis

The lymphohistiocytic T-cell lymphoma and peripheral T-cell lymphoma associated with haemophagocytic syndrome are two distinct clinicopathologic entities which have recently been described. Due to the high content of reactive histiocytes, they share similar problems in the differential diagnosis with several reactive and neoplastic conditions. The criteria for the recognition of these tumours, along with the mechanisms which might attract the macrophagic component, are reviewed and extensively discussed.