Overview

• There are many different types of atypical lymphocytes of varied morphology, though they tend to be identified as reactive or neoplastic in nature. These may be difficult to distinguish on morphological examination.

• • Atypical Lymphocyte Findings

  • Larger cell size
  • Irregular cell outline
  • Immature (less condensed) chromatin
  • Nucleoli
  • Basophilic cytoplasm

• • Types of Atypical Lymphocytes

  • Reactive lymphocytesEBV, CMV, HIV, toxoplasmosis, bordatella pertussis
  • Plasmacytoid lymphocytes (Türk cells) - small to medium lymphocytes with a deep blue cytoplasmReactive - the intermediate stage between a B cell and plasma cell
  • Neoplastic lymphocytesAcute lymphoblastic leukaemia, chronic lymphocytic anaemia, leukaemic phase of non-Hodgkin lymphoma

• • Examples

• • A reactive lymphocyte in a patient with acute mononucleosis.
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• • A plasmacytoid lymphocyte (Türk cell).
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