Reactive Lymphocytes / Benign Disorders

Epstein-Barr Virus

• Children and young adults with lymphadenopathy, hepatosplenomegaly and sometimes lymphoyctosis
• Typical features:
  • Large, atypical lymphoid cells
  • Intensely basophilic cytoplasm
  • Occasional cytoplasmic blebs
  • Scalloping around RBCs
  • May be associated with red cell agglutination

Bordetella Pertussis

• Paediatric patients with cough and dyspnoea (whooping cough)
• Associated with mature lymphocytosis
• Typical features:
  • Cleft nuclei
  • Basophilic cytoplasm
  • Scant cytoplasm
  • Condensed chromatin

Large Granular Lymphocytes

• Post-viral infection, organ transplant, chemotherapy
• Usually transient; if persistent and associated with anaemia or neutropaenia, suspicious of LGL leukaemia
• Features:
  • Large lymphoid cells with azurophilic granules
  • Mature chromatin
  • Copious cytoplasm

Dengue Infection

• Common viral infection in the tropics affecting all age groups. Typical features include fever, maculopapular rash, myalgias, bicytopaenia (leukopaenia and thrombocytopaenia) and transaminitis.
• Features:
  • Large, atypical lymphocytes
  • Intensely basophlic cytoplasm
  • Nuclear countour usually regular
  • Genuine thrombocytopaenia
  • May have profound neutropaenia

Polyclonal B lymphocytosis

• Typically middle-aged female smokers
• Associated with polyclonal increases in IgM
• Cytogenetic abnormalities of chromosome 3, especially +i(3)(q10)
• Rarely progresses to lymphoma
• Morphological features:
  • Binucleate large lymphoid cells
  • Abundant, basophilic cytoplasm
  • Nuclei may have slight indentations if not clearly bi-lobed
  • Mature chromatin, sometimes with prominent nucleoli