Objective: Erdheim-Chester disease (ECD) is a rare histiocytosis which has typical findings including central diabetes insipidus, restrictive pericarditis, perinephric fibrosis, and sclerotic bone lesions. ECD is primarily a disease of middle-aged adults, with a mean age of 46 years at diagnosis in the United States (range, 20–74 and 56 years in the French cohort (range, 29–86). The exact incidence is unknown due the lack of population-based mandatory reporting to national registries.
Case report: Patient-1 Patient-2 Patient-3 Patient-4 Patient-5 Sex Male Male Female Female Male Age at compilation 32 32 51 65 41 Age at diagnosis 28 29 48 64 37 Follow up from disease onset, mo 59 45 40 12 44 Constitional symptoms − − − − + Skeletal involvement + + + + + Extraskletal involvement + + − + + Cardiac involvement Coronary involvement − − − − − Pericardial involvement + − − − − Right atrial pseudotumor − − − − − Valvulopaty − − − − − Large vessel involvement − − − − − CNS involvement Central DI + − − + − SerebellarSyndrome − − − − − Extra−axial mass − + − − − Hypophyseal involvement − − − − Pulmonary involvement + − − − − Orbital involvement − − − − + Cutaneous involvement (xanthelasma) − − − − + Retroperitoneal involvement − − − − − Adrenal infiltration − − − − − Paranasal sinüs involvement − − − − − Maxillary involvement − − − − − Treatment + + + + + Peg IFN-α/IFN-α + − + + + Radiotherapy − − + − − Corticosteroids − − − − + Other − + − − +
Methodology: Data of five patients were retrospectively analyzed in our center. The mean age of the patients was 41.2 years (28–64 years) at the time of diagnosis. The mean follow-up period was 40 months (12–59 months).
Results: The patients were mostly diagnosed with the bone. The most commonly involved organ was the bone, followed by the central nervous system (CNS), heart, lung, periorbita, and skin, respectively. While bone involvement was observed in all patients, non-skeletal involvement was observed in 4 patients. Diabetes insipidus was detected in 2 patients. Patients received different treatments depending on the type of involvement and extent of the disease. Four patients received treatment with Peg-IFN, and one patient received radiotherapy due to the progression of the disease. Following excision of the mass, no recurrence was observed in one patient, and the patient was under follow-up without treatment. One of the patients was diagnosed with the disease before the first-line treatment with vemurafenib, therefore, a combination of vinblastine and methylprednisolone was used. However, a full response could not be achieved. IFN was used as the second-line treatment, and the patient was under follow-up with stable conditions. No patient passed away during the follow-up.
Conclusion: Of our patients, 60% were male, similar to the general epidemiological data. However, the mean age of our patients, who were American and French, were low. Evaluation of the expression levels of BRAFV600E was performed for three patients, but the results were negative. This may be due to the fact that one patient had overlapping entities with LCH and could not be evaluated with a method as sensitive as ddPCR, which is one of the most recent sequencing techniques. Although skeletal involvement was present in all patients, the absence of extra-axial involvement, such as life-threatening retroperitoneal involvement and adrenal involvement, was remarkable. Although the patients were BRAF V600E mutation negative and this made the conversion to vemurafenib therapy difficult, patients were followed up without progression during the conventional Peg-IFN therapy. Clinical profile and treatment approach algorithms of ECD patients in Turkey should be created with longer follow-up and multi-center data collection.
