Clinical history: A 28 year old female, presents with fever and painless cervical lymphadenopathy.
What is your diagnosis?
Discussion and answer
On microscopic examination under low magnification, the lymph node shows an effaced architecture with large discrete, pale areas in the paracortex. These pale areas consist of foci of necrosis with nuclear debris, surrounded by activated lymphocytes (CD8 positive), histiocytes and plasmacytoid monocytes (CD4 positive). Neutrophils are characteristically absent in these lesions.
Presence of areas of necrosis and monocytoid plasma cells can mimic malignant lymphoma.
The diagnosis is histiocytic necrotizing lymphadenitis (Kikuchi-Fujimoto disease)
The clinical history and the characteristic histological features are helpful in the diagnosis.