Two cases of histiocytic necrotizing lymphadenitis (Kikuchi-Fujimoto's disease) following diffuse large B-cell...

Histiocytic necrotizing lymphadenitis (HNL) is often mistaken for malignant lymphoma clinically and is also sometimes difficult to differentiate from lymphoma even histopathologically. In this report, we describe the first 2 reported cases of HNL following non-Hodgkin's lymphomas. The patients were 27- and 30-year-old women who developed cervical and axillary lymph node swellings, respectively, in the course of remission of diffuse large B-cell lymphoma. The affected lymph nodes showed the typical histology of HNL: irregular-shaped "necrotic" foci with histiocytes engulfing apoptotic bodies intermingled with large-sized blastic lymphocytes. These findings mimicked the partial involvement of large-cell lymphoma. However, the blastic cells were almost exclusively T cells, and numerous apoptotic bodies were present, which excluded the possibility of recurrence of diffuse large B-cell lymphoma.