What are the other Names for this Condition? (Also known as/Synonyms)

• Cerebral Rosai-Dorfman Disease
• Intracranial Rosai-Dorfman Disease
• RDD of Brain

What is Rosai-Dorfman Disease of Brain? (Definition/Background Information)

• Rosai-Dorfman disease (RDD) is a rare, benign condition that causes proliferation of histiocytes, a type of white blood cells, within the lymph nodes and other organs of the body. It can cause painless, lymph node enlargements at various sites in the body
• Apart from the lymph nodes, RDD can also involve other body tissues and organs, such as the skin, bone, breast, respiratory airways, and central nervous system. In such cases, it is known as extranodal Rosai-Dorfman disease
• Rosai-Dorfman Disease of Brain is a rare extranodal form of RDD, wherein along-with involvement of the lymph nodes, the brain is also affected. The condition is seen in both children and adults
• The individual can also have signs and symptoms of other organs along-with brain associated signs and symptoms, such as headaches, vomiting, walking difficulties, vision abnormalities, and seizures. The treatment of the condition is typically symptomatic, with surgery being the treatment of choice
• The prognosis of Rosai-Dorfman Disease of Brain depends on the severity of the presenting symptoms. Individuals with mild symptoms have a better prognosis than those with severe RDD of Brain. In some individuals, severe complications may develop and the prognosis may be guarded

Who gets Rosai-Dorfman Disease of Brain? (Age and Sex Distribution)

• Rosai-Dorfman Disease of Brain may affect children and adults, though an increased number of cases pertain to middle-aged and older adults (average age 40 years)
• Both male and female genders are affected
• All racial and ethnic groups are at risk; although, more cases of RDD are seen in Africans and Afro-Americans than in Caucasians

What are the Risk Factors for Rosai-Dorfman Disease of Brain? (Predisposing Factors)

• The risk factors for Rosai-Dorfman Disease of the Brain are not well-established
• However, some researchers believe that RDD, in general, may be influenced by certain viral and bacterial infections

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Rosai-Dorfman Disease of Brain? (Etiology)

The definitive cause of Rosai-Dorfman Disease of Brain is unknown. It may occur due to an abnormal immune system of the body, caused by a variety of triggers.

• Infectious etiology: Some researchers believe that RDD may be caused by viral infections, such as caused by varicella zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), and herpes virus; and, by bacterial infections caused by Brucella sp and Klebsiella
• The abnormal immune response results in abnormal growth and multiplication of histiocytes within the lymph nodes. The histiocytes are a component of the white blood cells (WBCs or leukocytes) in the body
• An associated increase in leukocyte count in peripheral blood may also be seen

What are the Signs and Symptoms of Rosai-Dorfman Disease of Brain?

The signs and symptoms of Rosai-Dorfman Disease of Brain can vary from one individual to another. Some are known to have mild symptoms, while others may have severe symptoms. Also, in some individuals, the symptoms are known to ‘appear and disappear’ over time.

The signs and symptoms of RDD of Brain may include:

• The brain locations involved include the cerebrum, cavernous sinus, parasagittal plane (along the division of the left and right side of brain), at the brainstem, near the hypothalamus, pituitary gland, etc. Dysfunction of these specific regions may occur, due to pressure effect on the brain
• Brain-associated symptoms may include:
  • Headache and vomiting that may be present for several months
  • Low-grade fever, in some cases
  • Blurred vision and loss of vision
  • Numbness
  • Walking difficulties, lack of coordination
  • Paralysis of one side
  • Generally, the tumor is solitary, well-defined, and mostly painless. In some cases, multiple lesions have been reported
• Fatigue
• Weight loss
• Anemia, resulting in pale skin, tiredness, and shortness of breath
• Involvement of the brain occurs more frequently than the spinal cord
• Lymphadenopathy or swollen lymph nodes; the enlargement is usually painless
  • The most commonly involved lymph nodes are the cervical (neck) lymph nodes, when it is termed cervical lymphadenopathy
  • Other lymph nodes involved include those located in the inguinal (groin), axillary (armpits), mediastinal (chest), and para-aortic region
  • Lymph nodes at other regions of the body may also be affected

Sometimes, in rare cases, lymph node involvement is not seen along-with Brain RDD.

How is Rosai-Dorfman Disease of Brain Diagnosed?

Rosai-Dorfman Disease of Brain is diagnosed using the following methods:

• A thorough physical examination and assessment of one’s complete medical history
• Radiological studies (X-ray, CT scan, MRI scan, etc.) of the affected region of the brain
• Complete blood count
• Tests to diagnose any underlying bacterial or viral infections
• Biopsy of the affected region of brain

A biopsy on the affected lymph node may be performed:

• Lymph node biopsy: A lymph node biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. The pathologist may use special techniques, such as immunohistochemistry stains, to help reveal the presence of the pathogen
• The lymph node biopsy may be performed through any of the following procedures:
  • Fine needle aspiration biopsy (FNAB): A device called a cannula is used to extract tissue or fluid from the lymph nodes
  • Lymph node core biopsy of the enlarged lymph node
  • Lymph node open biopsy of the enlarged lymph node
• Flow cytometry to rule-out lymphoma: The test helps identify cells as they flow through an instrument, called a flow cytometer. Flow cytometry measures the number and percentage of cells in a blood sample, and cell characteristics such as size, shape, and the presence of biomarkers on the cell surface

Note: A differential diagnosis may be undertaken to eliminate conditions presenting similar signs and symptoms, prior to arriving at a definite diagnosis.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Rosai-Dorfman Disease of Brain?

The complications of Rosai-Dorfman Disease of Brain may include the following:

• Emotional stress: Prolonged enlargement of the lymph nodes raising a concern for malignant conditions such as lymphomas
• Mass effect on the brain can result in severe complications
• Fluid in the brain or hydrocephalus
• Seizures and limb paralysis
• Recurrence of the tumor after surgery, which may be as high as 10-15%

How is Rosai-Dorfman Disease of Brain Treated?

Th treatment of Rosai-Dorfman Disease of Brain depends on the severity of the symptoms. If the symptoms are significant, then the following treatment measures may be considered:

• Steroid therapy for systemic RDD
• Surgical removal of enlarged lymph nodes
• Surgery (craniotomy) to remove brain tumor mass to reduce mass effect
• In cases where surgery is not possible due to location of the tumor, low-dose radiation therapy may be considered 
• Long-term medical follow-up (via serial imaging studies) for a period of 5-10 years is recommended

How can Rosai-Dorfman Disease of Brain be Prevented?

There are currently no preventive methods available for Rosai-Dorfman Disease of Brain.

What is the Prognosis of Rosai-Dorfman Disease of Brain? (Outcomes/Resolutions)

• The prognosis of Rosai-Dorfman Disease of Brain is based on the severity of the signs and symptoms
• Nevertheless, the prognosis is good in a majority of individuals with adequate treatment (including surgery). However, recurrences have been observed following invasive procedures
• In some individuals, severe complications may develop when the brain is involved. In such cases, the prognosis may be guarded

Additional and Relevant Useful Information for Rosai-Dorfman Disease of Brain:

General information on lymph nodes:

The lymph nodes are part of one’s immune system. The lymph nodes are present throughout the body, usually in groups. In normal healthy adults, one cannot feel (see or touch) the lymph nodes readily. However, if they are enlarged, they can be felt either by the individual himself/herself or by the healthcare provider.

Enlarged lymph nodes can occur in both benign and malignant conditions. Hence, the cause of enlarged lymph nodes should be evaluated. If no obvious cause for enlargement of lymph nodes is found, then the possibility of a lymph node malignancy should be ruled out.

In a majority of individuals, a lymph node swelling is caused by a benign process such as an inflammation or infection. In many cases, swollen lymph nodes are part of other signs and symptoms. This can help a healthcare provider arrive at a list of follow-up tests and ensure an accurate diagnosis. Superficial enlarged lymph nodes can be felt by the healthcare provider through palpation. Enlarged lymph nodes deep in the body are often detected by radiological studies such as X-rays, ultrasound scan, CT and MRI scans.

Some enlarged lymph nodes can be painful, while others may be painless. Depending upon the underlying cause, enlarged lymph nodes can be localized to a particular area of the body, or they can be generalized, meaning that they are present throughout the body.