{"id":34,"date":"2014-11-20T07:52:41","date_gmt":"2014-11-20T07:52:41","guid":{"rendered":"https:\/\/www.erdheim-chester.org\/?page_id=34"},"modified":"2026-06-24T16:58:08","modified_gmt":"2026-06-24T21:58:08","slug":"diagnose-2","status":"publish","type":"page","link":"https:\/\/www.erdheim-chester.org\/nb\/diagnosis\/","title":{"rendered":"Diagnose"},"content":{"rendered":"

[et_pb_section fb_built=”1″ _builder_version=”4.27.6″ _module_preset=”default” background_image=”https:\/\/www.erdheim-chester.org\/wp-content\/uploads\/2024\/12\/Untitled-design-96-1.png” background_position=”bottom_center” background_vertical_offset=”20%” custom_padding=”15px||15px||true|false” background_last_edited=”on|desktop” background_position_tablet=”bottom_right” background_position_phone=”center_right” global_module=”28071″ global_colors_info=”{}”][et_pb_row _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_heading title=”@ET-DC@eyJkeW5hbWljIjp0cnVlLCJjb250ZW50IjoicG9zdF90aXRsZSIsInNldHRpbmdzIjp7ImJlZm9yZSI6IiIsImFmdGVyIjoiIn19@” _builder_version=”4.27.4″ _dynamic_attributes=”title” _module_preset=”default” title_font=”–et_global_heading_font|300|||||||” title_text_color=”#FFFFFF” title_font_size=”40px” custom_margin=”||3px|||” title_font_size_tablet=”” title_font_size_phone=”25px” title_font_size_last_edited=”on|phone” global_colors_info=”{}”][\/et_pb_heading][et_pb_button button_url=”\/contact-us\/” button_text=”Contact Us” _builder_version=”4.27.4″ _module_preset=”default” custom_button=”on” button_text_size=”15px” button_text_color=”#C02E43″ button_bg_color=”rgba(10,22,64,0.53)” button_border_width=”0px” button_icon=”||divi||400″ button_icon_color=”#C02E43″ button_icon_placement=”left” button_on_hover=”off” global_colors_info=”{}” filter_opacity__hover_enabled=”on|hover” filter_opacity__hover=”70%”][\/et_pb_button][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ admin_label=”section” _builder_version=”4.16″ global_colors_info=”{}”][et_pb_row column_structure=”2_5,3_5″ admin_label=”row” _builder_version=”4.16″ background_size=”initial” background_position=”top_left” background_repeat=”repeat” global_colors_info=”{}”][et_pb_column type=”2_5″ _builder_version=”4.16″ custom_padding=”|||” global_colors_info=”{}” custom_padding__hover=”|||”][et_pb_image src=”https:\/\/www.erdheim-chester.org\/wp-content\/uploads\/2025\/02\/Slide1-scaled.jpeg” title_text=”Slide1″ show_in_lightbox=”on” show_bottom_space=”off” align=”center” force_fullwidth=”on” _builder_version=”4.27.4″ _module_preset=”default” module_alignment=”center” custom_margin=”||||false|false” custom_padding=”||||false|false” global_colors_info=”{}”][\/et_pb_image][\/et_pb_column][et_pb_column type=”3_5″ _builder_version=”4.16″ custom_padding=”|||” global_colors_info=”{}” custom_padding__hover=”|||”][et_pb_text admin_label=”Text” _builder_version=”4.27.6″ background_size=”initial” background_position=”top_left” background_repeat=”repeat” global_colors_info=”{}”]<\/p>\n

Diagnostic Overview<\/h3>\n

ECD is often a challenge to\u00a0diagnose, given that \u00a0many symptoms are not unique to ECD\u00a0and that ECD has similarities to multiple other medical conditions. ECD diagnosis is often delayed by years or even decades in some cases. A definitive diagnosis is usually based on a review of ECD-involved biopsy in combination with radiologic findings from PET-CT, CT, MRI, or bone scan. Mutational testing of biopsies is also becoming increasingly important in diagnosing ECD. Nearly 90 % or more of ECD patients seem\u00a0to have activation in the\u00a0MAPK pathway cascade caused by a genetic mutation in the MAPK pathway, and a smaller number have changes affecting a related pathway called PI3K-AKT. These pathways help cells grow and survive, and their abnormal activation is a key feature of ECD. These mutations are believed to be acquired during a person\u2019s lifetime (somatic) rather than inherited; therefore, these mutations are not passed through generations. If there is a suspicion of ECD, it is important for patients to be seen at specialized centers with expertise in hematology, pathology, radiology, neurology, and other subspecialties to accurately\u00a0diagnose\u00a0ECD and implement treatment in a timely manner.[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_text admin_label=”Text” _builder_version=”4.27.6″ link_text_color=”#35A4BB” background_size=”initial” background_position=”top_left” background_repeat=”repeat” hover_enabled=”0″ global_colors_info=”{}” sticky_enabled=”0″]<\/p>\n

Imaging is used for diagnosis<\/h3>\n

Non-invasive scans such as CT scan, PET\/CT scan (head to toes), MRI, bone scan, or echocardiogram are typical tests used to diagnose ECD.\u00a0 The PET\/CT is considered the most helpful in accurately diagnosing ECD and identifying the extent of the disease.<\/p>\n

Biopsy is used for diagnosis<\/h3>\n

If a mass or lesion is found within the body, a tissue biopsy will be performed as part of the diagnostic workup for ECD. A biopsy is often performed using a needle, but sometimes, a surgical biopsy is needed to get enough tissue and arrive at an appropriate diagnosis. A pathologist will study the tissue sample that is obtained via the biopsy.\u00a0ECD-affected tissue usually contains clusters of foamy (fat-containing) histiocytes with signs of chronic inflammation, often with Touton-type giant cells and fibrosis. The pathologist will conduct additional stains (dye tests) to check if specific markers are present in the ECD histiocytes. Skin and perirenal tissues are often more informative for the diagnosis and molecular analyses.<\/p>\n

Genetic Testing<\/h3>\n

Pathologists are increasingly performing genetic testing on a biopsy sample if ECD is suspected. If an ECD-known mutation is found, it will help lead to a more definitive diagnosis and is often needed to select the best treatment for a patient. Mutation testing does not always show a mutation, and it is important to remember that a mutation does not need to be found to achieve an ECD diagnosis or to allow for treatment.<\/p>\n

Diagnosis<\/h3>\n

To arrive at a correct ECD diagnosis or to rule out an ECD diagnosis, doctors rely upon the\u00a0findings of a biopsy of affected tissue and related imaging studies.\u00a0A trained pathologist should review tissue samples, and the imaging should be\u00a0reviewed by a radiologist, both of whom have knowledge of ECD.\u00a0It is critical for the pathologist, radiologist, and physician seeing the patient to communicate well with each other to arrive at the diagnosis.<\/p>\n

Systemic search for all areas of involvement<\/h3>\n

Once preliminary tests indicate an ECD diagnosis, it is important to make a systematic study of the organs possibly affected, including the skeleton, lungs, heart, large vessels, central nervous system, kidneys, eyes, pituitary, and\/or skin. An individual with ECD needs to be seen by many specialists to obtain an accurate baseline to determine the extent of the disease. This helps the medical team monitor ECD to see if treatments are effective and to take quick action if the disease begins to progress after treatment begins. Tests that should be expected include:<\/p>\n