Histiocytosis is an umbrella term that refers to a relatively uncommon group of syndromes associated with the overproduction of certain infection-fighting white blood cells known as histiocytes. The excess cells may then build up, form tumors and damage organs. Because histiocytosis often behaves similarly to cancer, it is usually classified and treated as such.

Histiocytosis can be categorized based on the type of immune cells involved: macrophages, monocytes or dendritic cells. The most common type is Langerhans cell histiocytosis, which occurs when the body accumulates too many immature Langerhans cells. These tissue-resident macrophages form a protective network across the skin barrier and can potentially enter nearby lymph nodes.

What Prompts the Development of Histiocytosis?

Recent studies suggest that some types of histiocytosis may be linked to a genetic defect; however, the precise causes remain unknown. Most cases are diagnosed in patients who are younger than 15.

What Are the Symptoms of Histiocytosis?

In children, histiocytosis frequently involves the skull or other bones in one or more areas of the body. In many cases, the first sign is a scalp rash. Other symptoms can include:

  • Bone pain or limping
  • Abdominal discomfort and bloating
  • Chronic ear infections and discharge
  • Fever, fatigue and irritability
  • Nausea, vomiting and loss of appetite
  • Excessive thirst and frequent urination
  • Headaches, dizziness and mental confusion
  • Bulging eyes and vision problems
  • Delayed puberty and short stature

How Is Histiocytosis Diagnosed?

The diagnostic process for histiocytosis typically begins with a physical examination, blood work and imaging studies. A bone tumor may produce a distinctive “punched-out” appearance on an X-ray. If histiocytosis is suspected, a physician will usually order a tissue biopsy or a bone marrow aspiration to confirm the diagnosis.

What Are the Treatment Options for Histiocytosis?

Depending on the extent of the condition, histiocytosis may be treated with chemotherapy and/or steroids. The goal is to inhibit the overproduction of histiocytes by suppressing the immune system. In some cases, radiation therapy or surgery may be used to address a bone lesion.

The pediatric hematology/oncology experts at Tampa General Hospital specialize in diagnosing and treating all types of solid tumors and blood and bone marrow malignancies in infants, children and young adults. We create a customized treatment plan for each patient that fully reflects his or her unique needs.