Erdheim-Chester disease presenting with destruction of a metacarpal

Erdheim-Chester disease: a comprehensive review from the ophthalmologic perspective

Erdheim-Chester disease (ECD) is a rare clonal histiocytic neoplasm with less than 1200 documented cases to date. The disease is life-threatening and difficult to recognize, although increasing awareness as well as the integration of clinical, imaging, pathology information , and genetic studies have led to a recent exponential increase in new reported cases. ECD affects multiple organs and systems, including skeletal, neurologic, and cardiovascular. Pulmonary, retroperitoneal, and cutaneous lesions have also been reported in various combinations. Until the discovery that more than half of ECD patients harbor the BRAF-V600E mutation or other mutations in the mitogen-activated protein kinase (MAPK) and RAS pathways, Interferon-a was the first-line treatment. Nowadays BRAF and MEK-inhibitors targeted therapies are the mainstay of treatment. Ophthalmologic involvement occurs in 25% -30% of ECD cases, usually in the form of orbital involvement presenting with exophthalmos and ophthalmoplegia. Other ophthalmologic manifestations include palpebral xanthelasmas, anterior uveitis and vitritis, optic disk edema, choroidal infiltration, recurrent serous retinal detachment, retinal drusen-like deposits and retinal pigment epithelial changes. ECD patients can also present with ocular symptoms as a result of adverse effects of the treatment regimens. In some cases with smoldering or protean symptoms, the emergence of eye manifestations triggered the diagnosis. Ophthalmologists have to be aware of the disease, recognize the constellation of ECD symptoms, and contribute to the diagnosis, treatment, and follow-up of ECD patients.

Clinical presentation, imaging and response to interferon-alpha therapy in Erdheim-Chester disease: case-based review

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis associated with BRAFV600E mutations in more than 50% of cases and presenting with 95% with skeletal lesions. However, cutaneous, pulmonary, large vessels and central nervous system involvement can also occur. We report a case of a 25-year-old woman who was admitted in 2018 for exploration of diffuse bone pain and rashes on the face. Her current symptoms had started 14 months earlier and consisted of bone pain, affecting the legs. She had periodic low-grade fever, asthenia and xanthelasma-like papules appeared on face. At admission, physical examination showed bilateral and symmetrical long bone pain, especially in the knees and multiple xanthelasma-like papules around the eyelids, cheeks and chin. Laboratory tests revealed elevated erythrocyte sedimentation rate and C-reactive protein. Magnetic resonance (MR) imaging showed multiple mixed bone lesions with a hyperintensive MR signal on PD FS and hypointense signal on T1of the femur and tibia. Bone scintigraphy indicated bilateral and symmetrical metaphyseal and diaphyseal increased uptake. Abdominal computed tomography (CT) scan showed infiltration of the perirenal fat. Biopsy of the skin revealed histiocytic infiltration, which was CD68-positive and CD100-positive, confirming the diagnosis of ECD. Patient was treated with interferon-α (IFN-α) plus methylprednisolone. After 6 months of treatment her clinical condition partly improved: a reduction of pain on visual analogue scale (VAS) scale, significant decrease of methylprednisolone dose and specific dynamics according to bone MR imaging data, however, no change in symptoms attributed to skin rash was noted. We also provide the literature review results of IFN-α treatment efficacy in Erdheim-Chester disease involving the skin and musculoskeletal system with MR imaging changes.

Erdheim-Chester Disease: a comprehensive review of the literature

Erdheim-Chester Disease (ECD) is a rare form of non Langerhans' cell histiocytosis. Individuals affected by this disease are typically adults between their 5th and 7th decades of life. Males and females are almost equally affected. The multi systemic form of ECD is associated with significant morbidity, which may arise due to histiocytic infiltration of critical organ systems. Among the more common sites of involvement are the skeleton, central nervous system, cardiovascular system, lungs, kidneys (retroperitoneum) and skin. The most common presenting symptom of ECD is bone pain. The etiology of ECD is unknown yet thought to be associated with an intense TH1 immune response. It may also be associated with the V600E BRAF mutation, as described in as many as half of the patients in recent studies. Bilateral symmetric increased tracer uptake on ^99mTc bone scintigraphy affecting the periarticular regions of the long bones is highly suggestive of ECD. However, definite diagnosis of ECD is established only once CD68(+), CD1a(−) histiocytes are identified within a biopsy specimen. At present, this obscure ailment embodies numerous challenges to medical science. Given its rarity, it is diagnostically elusive and requires a high level of clinical suspicion. Therapeutically, it is of limited alternatives. Currently, interferon-α is the most extensively studied agent in the treatment of ECD and serves as the first line of treatment. Treatment with other agents is based on anecdotal case reports and on the basis of biological rationale. Nevertheless, cladribine (2CDA), anakinra and vemurafenib are currently advocated as promising second line treatments for patients whose response to interferon-α is unsatisfactory. Overall, the 5 year survival of ECD is 68%. Herein, the authors mustered and brought about a panoramic consolidation of all the relevant facts regarding ECD. This work highlights the different clinical, radiological and pathological manifestations associated with ECD, the differential diagnoses, the various treatment options and the acknowledged science explaining the disease.