ROSAI DORFMAN DISEASE

Rosai-Dorfman disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy (SHML), is a rare benign disorder characterized by the overproduction of a type of white blood cell called histiocytes. These histiocytes accumulate in various tissues and organs, most commonly in the lymph nodes, but can also affect the skin, spleen, liver, and other areas.
Lecture Outline:
Introduction
Definition and history of RDD
Classification within histiocytic disorders
Pathology
Histological features
Characteristic "emperipolesis" phenomenon
Immunophenotyping of histiocytes
Molecular pathogenesis
Recent identification of mutations in MAPK pathway genes
Clinical Manifestations
Lymphadenopathy: Most common presentation
Typically painless and non-tender
Often involves cervical lymph nodes
Extranodal involvement
Skin: Erythematous nodules or plaques
Lungs: Respiratory symptoms and infiltrates
Other sites: Liver, spleen, bone marrow, central nervous system
Diagnosis
Histological examination: Gold standard
Immunohistochemistry: Confirms histiocytic nature and excludes other entities
Laboratory tests: May show elevated white blood cell count, anemia, and polyclonal hypergammaglobulinemia
Differential Diagnosis
Other histiocytic disorders: Langerhans cell histiocytosis, dendritic cell sarcoma
Infectious diseases: Tuberculosis, fungal infections
Lymphoma
Autoimmune diseases
Treatment
Most cases resolve spontaneously or with conservative management
In refractory cases, various therapies may be considered, including:
Chemotherapy
Radiation therapy
Immunotherapy
Surgery
Prognosis
Generally favorable, with most patients experiencing complete remission
Recurrence is possible, especially in cases with extranodal involvement
Summary
Rosai-Dorfman disease is a rare but benign histiocytic disorder characterized by the accumulation of abnormal histiocytes in various tissues.
It typically presents as painless lymphadenopathy but can also involve other organs.
Diagnosis is based on histological and immunohistochemical findings.
Treatment is usually not necessary, as the disease often resolves spontaneously.
Prognosis is generally good, with a low risk of recurrence.