What is sinus histiocytosis in a lymph node?

Sinus histiocytosis with massive lymphadenopathy (SHML) is a rare disorder of unknown etiology, usually associated with lymph node enlargement in various superficial or deep sites. It usually shows a prolonged clinical course with occasional exacerbation and remission phases.

What is reactive sinus histiocytosis?

Sinus histiocytosis is a common nonspecific finding in lymph node biopsy specimens. It may be accompanied by follicular or interfollicular hyperplasia. It may also be seen in lymph nodes draining sites of inflammation or tumors, especially breast and gastrointestinal carcinomas.

Is sinus histiocytosis cancerous?

Sinus histiocytosis is often associated with malignant tumor. It is considered as a sign of the host’s immune activation with favorable prognostic significance. Nevertheless, such lymphadenopathy mimics a metastatic lymph node, making proper staging difficult.

What causes sinus histiocytosis?

Researchers have suggested that the disorder may be caused by an infectious agent, immunodeficiency, or autoimmunity. Symptoms of Rosai-Dorfman disease develop due to the overproduction and accumulation of histiocytes in the channels (sinuses) that allow for the passage of lymph (sinus histiocytosis).

What is a reactive lymph node?

Reactive lymph nodes are a sign that your lymphatic system is working hard to protect you. Lymph fluid builds up in lymph nodes in an effort to trap bacteria, viruses, or other harmful pathogens. This helps to keep the infection from spreading to other parts of your body.

What lymphadenopathy means?

Lymphadenopathy refers to lymph nodes that are abnormal in size (e.g., greater than 1 cm) or consistency. Palpable supraclavicular, popliteal, and iliac nodes, and epitrochlear nodes greater than 5 mm, are considered abnormal. Hard or matted lymph nodes may suggest malignancy or infection.

What is reactive lymphadenitis?

Overview. You’ve probably had swollen glands at some point in your life, such as when you’ve had a cold or other infection. Swollen glands are actually swollen lymph nodes, which are often reactive lymph nodes. You might also hear this condition referred to as reactive lymphadenopathy.

What is Dermatopathic lymphadenopathy?

Dermatopathic lymphadenopathy is characterized by expansion of the lymph node paracortex with numerous Langerhans cells and macrophages containing phagocytosed melanin. In infiltrated lymph nodes, aggregates of small to medium-sized lymphoid cells with cerebriform nuclei are seen in the paracortex.