What is Histiocytosis?
Histiocytosis is the abnormal build up of immature histiocytes in some parts of your body. Histiocytes are infection-fighting cells that are a part of your immune system. The disease can be local (i.e., affecting just one organ or part of bodily system), or widespread, affecting multiple areas of your body and multiple bodily systems. Areas affected by histiocytosis often develop tumors or organ damage.
Histiocytosis can affect any system of your body, including your endocrine system and nervous system.
Consequently, histiocytosis is not limited to your pituitary gland. However, the hypothalamic and pituitary regions are the areas most often affected if the disease occurs in your brain. When this happens, it often has very specific effects on your pituitary gland. Therefore, you may need to incorporate the services of an endocrine specialist into your overall disease management plan.
The hallmark of histiocytosis is an abnormal increase in the number of immune cells called histiocytes. There are three common types of histiocytosis:
- Langerhans cell histiocytosis (histiocytosis X)
- Malignant histiocytosis syndrome (T-cell lymphoma)
- Non-Langerhans cell histiocytosis (hemophagocytic syndrome)
For a long time, histiocytosis has been thought of as a cancer-like disease. However, recent research has suggested that some forms may be caused by an autoimmune condition.
This section focuses on Langerhans cell histiocytosis (histiocytosis X); the most common form of the disease.
Symptoms of Histiocytosis
Because histiocytosis is a systemic disease and can affect any part of the body, it can cause a wide range of symptoms. Furthermore, some patients with histiocytosis have no symptoms at all.
Symptoms in children can include the following:
- Abdominal pain
- Bone pain
- Delayed puberty
- Long-term ear drainage
- Eyes that appear to stick out (protrude), with protrusion increasing over time
- Frequent urination
- Mental deterioration
- Rash (petechiae or purpura)
- Seborrheic dermatitis of the scalpv
- Short stature
- Swollen lymph glands
- Weight loss
Children over 5 years old often have only bone involvement.
Symptoms in adults can include the following:
- Bone pain
- Chest pain
- General discomfort, uneasiness, or ill feeling (malaise)
- Increased volume of urine
- Shortness of breath
- Thirst and increased drinking of fluids
- Weight loss
Treatments for Histiocytosis
Treatment will be determined after extensive testing gives a clear picture of the extent of your disease. If your disease is isolated and not producing severe symptoms, simple observation may be all that is required. If your disease is widespread or severely damaging a particular organ or body system, more drastic treatment, such as organ transplants or a bone marrow transplant may be needed. However, it is extremely rare for Langerhans cell histiocytosis to require such extensive treatment.
Although not technically a cancer, Langerhans cell histiocytosis is often treated much like cancer. Radiation and chemotherapy are the mainstays of treatment.
- Cyclophosphamide is a chemotherapy agent that fights Langerhans cell histiocytosis by decreasing white blood cell counts, including histiocytes. The side effects of cyclophosphamide can be quite severe and can include upset stomach, vomiting, diarrhea, hair loss, and other side effects associated with chemotherapy.
- Etoposide is a chemotherapy drug that works by decreasing growth in both Langerhans cells and regular cells in your body. Because it affects normal cells, it can have severe side effects such as nausea, lethargy, vomiting, and other side effects associated with chemotherapy.
- Methotrexate is a chemotherapy drug sometimes used to treat the skin condition psoriasis. Similar to cyclophosphamide, it attacks Langerhans cells by limiting the number of white blood cells produced in your bone marrow. It is often associated with severe side effects such as stomach inflammation, fever, pain, dizziness, and other side effects linked to chemotherapy. It should not be administered if you are pregnant.
- Vinblastine is a chemotherapeutic agent that destroys the cellular skeletons of your white blood cells. It destroys Langerhans cells and other white blood cells and can therefore have serious side effects, including increased susceptibility to bacterial, viral, and fungal infections.
Radiation therapy or surgery also may be used to treat bone lesions.
Other treatments may include the following:
- Respiratory support
- Physical therapy
- Special shampoos for scalp problems
- Supportive care to relieve symptoms
- Steroids to reduce inflammatory symptoms
Hormone replacement therapy
If your Langerhans cell histiocytosis is damaging your pituitary gland or hypothalamus, you may be referred to an endocrinologist for hormone replacement therapy. This treatment will alleviate the symptoms caused by the absence of certain hormones in your blood that were once produced by your pituitary gland.
If the disease has damaged the ability of your pituitary gland to produce antidiuretic hormone, resulting in diabetes insipidus, your doctor can prescribe a synthetic hormone called desmopressin to relieve the symptoms.
How common is Langerhans cell histiocytosis?
Langerhans cell histiocytosis is thought to affect roughly 1 in 200,000 people each year. It is most often seen in children ages 1 to 15. The rate peaks among children ages 5 to 10 years old.
The disease may be underdiagnosed because it can mimic other diseases or even physical trauma.
How is Langerhans cell histiocytosis (histiocytosis X) diagnosed?
Langerhans cell histiocytosis is usually diagnosed when it is suspected after other conditions have been ruled out. Because the disease is so variable and because it can affect many different areas of your body, the process of obtaining a diagnosis can be complicated. If the disease is suspected in a child, tests may include the following:
- Skin biopsy to check for the presence of Langerhans cells
- Bone marrow biopsy to check for the presence of Langerhans cells
- Complete blood count (CBC)
- X-rays of all the bones in the body (skeletal survey) to find out how many bones are affected
Adult tests may include the following:
- Bronchoscopy with biopsy
- Chest x-ray
- Pulmonary function tests
Langerhans cell histiocytosis (histiocytosis X) is sometimes associated with cancer, and computed tomography (CT) scans and biopsies should be done to rule out malignancy.