Ki-67 Labeling Indices in 'Classic' versus 'Blastoid' Mantle Cell Lymphomas--Proposed Cutoff Values for Routine Diagnostic Workup.

Background: Mantle-cell lymphoma (MCL) is a unique entity of peripheral B-cell lymphoma that has a discrete morphologic, immunologic, and genetic phenotype, with more common 'classic' and less frequent 'blastoid' and 'pleomorphic' variants, associated with an aggressive clinical course. The aim of this study was to analyze proliferation (Ki-67) indices of 'classic' (c-MCL) and 'blastoid' (b-MCL) variants of a cohort of MCL and to suggest cut off values for the Ki-67 proliferation index in these two subsets.

Materials And Methods: MCL cases diagnosed over 4 1/2 years at Section of Histopathology, Department of Pathology and Laboratory Medicine, Aga Khan University Hospital, Karachi were retrieved and reviewed.