Does the BRAFV600Emutation herald a new treatment era for Erdheim-Chester disease? A case-based review of a rare and difficult to diagnose disorder

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.

Choroidal mass as the first presentation of Erdheim-Chester disease

Purpose

To describe a choroidal mass that proved to be histiocytic choroidal infiltration in Erdheim-Chester disease.

Observations

A 54-years-old Caucasian male presented to our Retina Clinic with a suspect of choroidal melanoma in the left eye. Dilated fundus exam of the left eye showed a yellow-grey lesion along the inferior arcade, with sub-retinal fluid clinically visible. Enhanced depth imaging-OCT (EDI-OCT) showed a dome-shaped choroidal lesion with hyperreflective exudation present between the inner retina and the retinal pigment epithelium (RPE). On fundus autofluorescence the lesion appeared to have a diffuse speckled hyper-autofluorescent pattern secondary to the exudative subretinal material. On ultrasound, the lesion appeared hyper-echoic and dome-shaped, with a baseline thickness of 6.13 mm. Indocyanine green angiography (ICGA) was performed and showed hypocyanescence of the lesion from the early phases that persisted through the whole exam. Chest CT with contrast showed an abnormal, non-calcific, eccentric thickening of segments of the aorta (“coated aorta”) and PET an abnormally strong labeling of the distal ends of the long bones. An additional proximal tibial biopsy was performed to confirm the diagnosis on histology of Erdheim-Chester disease and the patient was started on oral prednisone. The choroidal mass progressively shrunk and the subretinal exudative material on top partially reabsorbed.

Conclusions and importance

Intraocular involvement in Erdheim-Chester disease is extremely rare but as a result of recent better awareness the number of new diagnosis is increasing. Erdheim-Chester disease should be considered in the differential of every choroidal mass.

Resolved heart tamponade and controlled exophthalmos, facial pain and diabetes insipidus due to Erdheim-Chester disease

A 69-year-old woman suffering from exophthalmos and facial pain came to us referred for aetiological diagnosis of exophthalmos. Orbital MRI showed thinned extrinsic ocular musculature, intraconal fat infiltration, retro-ocular compression and thickening of maxillary and sphenoid sinus walls. She had been suffering from diabetes insipidus for the last 7 years. During our diagnosis process, she presented signs of cardiac tamponade. Transthoracic heart ultrasound revealed large pericardial effusion and a heterogeneous mass that compressed the right ventricle. No osteosclerotic lesions on appendicular bones were present. Pericardiocentesis temporarily controlled tamponade and corticoid therapy temporarily abated exophthalmos. Pericardiectomy definitively resolved tamponade. Histological examination of pericardial tissue was conclusive of Erdheim-Chester disease. Exophthalmos responded to pegylated interferon-alpha-2a. Facial bone pain disappeared after zoledronic acid and interferon treatment. During interferon therapy, the patient suffered from a severe generalised desquamative exanthema that slowly resolved after discontinuing interferon. Diabetes insipidus remains controlled with desmopressin.

Erdheim-Chester Disease Presenting with Secondary Hypertension as a Result of Bilateral, Proximal Renal Artery Stenosis: A Case Report

Erdheim-Chester disease (ECD) is a rare, non-Langerhans cell histiocytosis presenting most commonly with bone and central nervous system symptoms, including but not limited to bone pain and diabetes insipidus. We present a known case of ECD, which was referred for secondary hypertension workup and diagnosed with severe, proximal, bilateral renal artery stenosis.

Bioinformatics Approach for Prediction of Functional Coding/Noncoding Simple Polymorphisms (SNPs/Indels) in Human BRAF Gene

This study was carried out for Homo sapiens single variation (SNPs/Indels) in BRAF gene through coding/non-coding regions. Variants data was obtained from database of SNP even last update of November, 2015. Many bioinformatics tools were used to identify functional SNPs and indels in proteins functions, structures and expressions. Results shown, for coding polymorphisms, 111 SNPs predicted as highly damaging and six other were less. For UTRs, showed five SNPs and one indel were altered in micro RNAs binding sites (3' UTR), furthermore nil SNP or indel have functional altered in transcription factor binding sites (5' UTR). In addition for 5'/3' splice sites, analysis showed that one SNP within 5' splice site and one Indel in 3' splice site showed potential alteration of splicing. In conclude these previous functional identified SNPs and indels could lead to gene alteration, which may be directly or indirectly contribute to the occurrence of many diseases.