Rosai-Dorfman disease: tumor biology, clinical features, pathology, and treatment.

Background: Rosai-Dorfman disease (RDD) is a rare, nonmalignant clinical entity characterized by a group of clinical symptoms and characteristic pathological features.

Methods: Articles that reviewed tumor biology, clinical features, pathology, and treatment for RDD were identified in a search of the literature for the years 1990 to 2014. The results from this body of literature were reviewed and summarized.

Dendritic cell and histiocytic neoplasms: biology, diagnosis, and treatment.

Background: Dendritic and histiocytic cell neoplasms are rare malignancies that make up less than 1% of all neoplasms arising in lymph nodes or soft tissues. These disorders have distinctive disease biology, clinical presentations, pathology, and unique treatment options. Morphology and immunohistochemistry evaluation by a hematopathologist remains key for differentiating between these neoplasms.