Physicians' Resource Center


The Histiocytosis Association was created to help patients and families navigate all types of histiocytic disorders. To that end, we have provided a list of resources you as medical professionals can use to gain more knowledge on histiocytic disorders and to share with your patients and their families to better understand histiocytosis.

If this is your first interaction with the Histiocytosis Association, we encourage you to click on the links below to learn more about us.

About UsOrganizational History, and Our Impact


Click on the links to download a printable version of the brochures

Webinars and Educational Videos

Click here to see the main webinar page and here for the educational video series.

Click the arrows below to see some of our recent webinars.

Histiocytosis Research:

Clinical Trials

Histiocytosis Follow-up Study

INTO-HLH Registry

NACHO (North America Consortium for Histiocytosis) Flyer

The Histiocytosis Association tries to maintain the most up to date list of available studies, registries, and clinical trials open to patients with all histiocytic disorders. Here is a link to the Registries & Clinical Trials page for more information on current trials, registries, and research opportunities, as well as a few opportunities featured below.

Research Grant Program

The Histiocytosis Association Research Program operates on an annual cycle. In the second quarter of each year, the Association begins a new cycle with an official announcement that the process is open, typically in mid-April, inviting physicians and scientists to review the Request for Research Proposals (RFRP) guidelines and application. The announcement is directed to thousands of healthcare professionals worldwide via the Association’s website and through email and mail campaigns. The RFRP is also distributed to numerous professional medical services and groups, and other nonprofit organizations, for circulation to their membership, extending the reach of this program as deeply as possible into the world of research and science.

We support scientific research investigating the causes, mechanisms, and improved means of treatment of histiocytic disorders. Research proposals are evaluated on the basis of science, feasibility, and relevance. All proposals are expected to address one or more of the histiocytic disorders. While all areas of research relevant to the histiocytoses will be considered, those of particular interest are listed below:

  • Mechanisms of disease pathogenesis
  • Biology (maturation, migration and immune function) of dendritic cells, macrophages and/or lymphocytes in disease pathogenesis
  • Derangements of cytokine production or function
  • Neurologic and neuropsychiatric manifestations of histiocytosis
  • Studies of rare histiocytoses -- Juvenile xanthogranuloma,
  • Erdheim-Chester disease, Rosai-Dorfman disease
  • Studies of histiocytic disorders in adults
  • Discovery of new disease markers
  • Quality of life, symptomatology, and survivorship

Click here to learn more about our research grant program.

NCCN Guidelines for LCH,ECD and RDD (Histiocytic Neoplasms)

In 2022, the National Comprehensive Cancer Network® (NCCN®) - an alliance of leading cancer centers - announced the publication of new NCCN Guidelines® for histiocytosis. These clinical practice guidelines provide the latest evidence and expert-consensus for diagnosing and treating the three most common forms of histiocytosis in adults: Langerhans cell histiocytosis (LCH), Erdheim-Chester Disease (ECD,) and Rosai Dorfman Disease (RDD). Although the guidelines are focused on adult patients, there may be insight for pediatric physicians as well.

You can download the free app here to view the Histiocytic Neoplasms guidelines. The Guidelines are currently focused for medical professionals however we hope to eventually help NCCN to develop patient guidelines as well.

The NCCN comprises 30 leading cancer centers that are dedicated to improving patient lives through research and education, and the development of valuable resources to help physicians, researchers, patients, and families. In a recent press release by NCCN, the Histiocytosis Association was honored to be able to share our excitement and support, alongside the ECD Global Alliance team and others.

The NCCN Guidelines can help patients, families and physicians access the latest information about symptoms, diagnosis, treatment, and more. They are useful tools when seeking approvals for coverage of drugs and therapies. They are available to access or download globally with a free NCCN account through their website or mobile app, which many physicians actively use in their practices. The guidelines are updated at least once a year and can be accessed at any time. You can view the published guidelines on NCCN’s website listed as “histiocytic neoplasms”. If using the guidelines outside of the United States, consider consulting with the NCCN Panel members shown on the first pages of the guidelines to discuss availability and coverage in other regions. While they are currently specific to adults with histiocytosis, these guidelines may also be beneficial for treatment options for pediatric patients. 

(Guidelines are listed as "histiocytic neoplasms")

Histiocyte Society

Committed to Research

The Histiocyte Society is a professional medical association comprised of more than 200 physicians and scientists from around the world. Members of the organization are considered to be the leaders in understanding and treating histiocytic disorders. The Society is committed to advancing knowledge about histiocytic disorders and improving outcomes for patients through the planning, development, sponsorship, and oversight of clinical research.

True Partners

For more than 35 years, the Histiocytosis Association has served as a partner, secretariat and the primary source of funding for the Histiocyte Society. The Association’s support of the Society includes:

  • Organizing and managing the Society’s annual scientific and Executive Board meetings,
  • Managing the overall organizational, administrative and financial operations,
  • Aiding in the development of organizational guidelines and operating procedures,
  • Building, developing and maintaining the organization and annual meeting websites,
  • Facilitating communication between Society members and the Executive Board, and
  • Building and managing the Society’s membership database.

Conducting these activities alleviates the Society’s leadership of the administrative duties associated with running a volunteer-based, nonprofit organization and allows them to focus solely on research and treatment.

The partnership is demonstrated again each year during the Association’s research funding cycle. The Society’s Scientific Committee conducts a comprehensive review of the applications for funding received by the Association. This is the first and a vital step in the overall review process and provides the basis for the Association’s Board of Trustees to select the very best applications for funding.

Histiocyte Society Fact Sheet

Click here to learn more about the Society.

Histiocyte Society Consensus Guidelines for HLH

In January 2023, the Histiocyte Society published "HLH/MAS Consensus Management Efforts, Expert Help Diagnosing and Managing HLH", which curates the most recent consensus-based guidance manuscripts, organized by the HS and/or affiliated organizations and authored by HS experts, to assist with the diagnosis and management of HLH across many different contexts.

Access the Consensus Guidelines here.

The Histio Warrior Care Bag Program

The Histiocytosis Association is dedicated to providing emotional and educational support to address the needs of patients and families affected by histiocytic disorders. In addition to providing reliable, disease-specific information and resources, we also hope to provide a source of comfort and connection to the Histio Community.

To learn more or request Histio Warrior Care bags for your institution, please contact the Histiocytosis Association by phone (856) 589-6606 or email