Langerhans cell histiocytosis (LCH) is a rare disease characterized by abnormal proliferation of Langerhans cells. We present the case of a 9-year-old girl complaining of recent belt-like dorsalgia, whose imaging revealed dorso-lumbar scoliosis and a tumor mass at the posterior arch of T11 with posterior epidural infiltration. Surgical decompression and tumor resection were performed, histopathologically confirming the diagnosis of LCH. This abstract highlight the diagnostic and therapeutic challenges of LCH, emphasizing the importance of a multidisciplinary approach for effective management of this rare disease. Additionally, it underscores the relevance of early intervention and meticulous follow-up to ensure optimal outcomes for patients with LCH.

The Aim: To make the analyses the clinical characteristics of patients with arrhythmic storm and possibility of radiofrequency ablation for prevention arrhythmogenic form of sudden cardiac death. Material and Methods: In the observation were included 40 patients (90.0% male, average age - 62.2±10.3 years) with implantable cardioverter-defibrillators, in which the episodes of arrhythmic storm (AS) were registered. All patients underwent "enhanced" antiarrhythmic therapy, and in some cases, inotropic drug support. In patients with hemodynamically tolerated VT, electroanatomic mapping was performed. Mapping and ablation of tachyarrhythmias were performed using the navigation system Carto XP (Biosense Webster, USA). Catheter ablation was performed against the background of tachycardia with subsequent destruction of all potential reentry circles, fragmented and late potentials. Results: The arrhythmic storm was recorded at different stages after implantation; the median time of occurrence of AS episodes from the moment of implantation was 5.2 months. The number of adequate electrical stimulations during AS was 8.2±4.1 per day. In 17 (42,5%) patients was registered monomorphic ventricular extrasystoles, in 12 (30,0%) - pleomorphic tachycardias, in 23 (57,5%) –ventricular tachycardias (VT). In primary catheter ablation, the acute efficiency of catheter destruction of the substrate of clinically significant VT was 60.0% (24 patients). VT after RFA was observed in 20 patients (50%). In 15 patients (37.5%), there was no induction of any VT. In the postoperative period in a hospital setting, ventricular tachyarrhythmias did not recur in any of the patients, and no deaths episodes were recorded. Ablation of trigger mechanisms of the Purkinje potential caused a distinct positive effect: ventricular tachyarrhythmias were not induced, including during aggressive ventricular pacing. No new episodes of ventricular tachyarrhythmia and ICD triggering were recorded during the two years of observation. Conclusions: 40% of patients with arrhythmic storm require emergency catheter ablation. In 90% of cases of arrhythmic storm occurs implantable cardioverter-defibrillators. Catheter ablation in all cases made it possible to control the arrhythmic storm, including over a long period of observation.