Vemurafenib has an objective and sustained efficacy in BRAF(V600E)-mutated ECD as second-line therapy. In contrast to melanoma, no resistance has emerged to date after 6 to 16 months.

Key Points• The association of both Langerhans cell histiocytosis and Erdheim-Chester disease is not exceptional. • This association is linked to BRAF V600E mutation.Histiocytoses are a group of heterogeneous diseases that mostly comprise Langerhans cell histiocytosis (LCH) and non-LCH. The association of LCH with non-LCH is exceptional. We report 23 patients with biopsy-proven LCH associated with Erdheim-Chester disease (ECD) (mixed histiocytosis) and discuss the significance of this association. We compare the clinical phenotypes of these patients with those of 56 patients with isolated LCH and 53 patients with isolated ECD. The average age at diagnosis was 43 years. ECD followed (n 5 12) or was diagnosed simultaneously with (n 5 11) but never preceded LCH. Although heterogeneous, the phenotype of patients with mixed histiocytosis was closer to that of isolated ECD than to that of isolated LCH (principal component analysis). LCH and ECD improved in response to interferon alpha-2a treatment in only 50% of patients (8 of 16). We found the BRAF V600E mutation in 11 (69%) of 16 LCH lesions and in 9 (82%) of 11 ECD lesions. Eight patients had mutations in both ECD and LCH biopsies. Our findings indicate that the association of LCH and ECD is not fortuitous and suggest a link between these diseases involving the BRAF V600E mutation. (Blood.

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The splenic complications of acute malaria include two different prognostic and treatment entities: splenic infarction and splenic rupture. This is the first case of splenic infarction during an acute malaria due to Plasmodium ovale in a 34-year-old man. As in the majority other described cases of splenic infarction, the course was spontaneously favourable, suggesting that this complication was relatively benign compared to splenic rupture, which is life-threatening and usually necessitating surgery.