Clinical characteristics and outcome of pediatric patients diagnosed with Langerhans cell histiocytosis in pediatric hematology and oncology centers in Poland

Efficacy and safety of vemurafenib in Langerhans cell histiocytosis (LCH): A systematic review and meta-analysis

Almost half of the patients with Langerhans cell histiocytosis (LCH) are refractory to primary induction chemotherapy or undergo reactivation. The ideal treatment modality for refractory/relapsed LCH is yet not evidenced. This review aimed to determine the efficacy and safety of vemurafenib (a BRAF pathway inhibitor) in LCH, particularly the refractory/relapsed cases. The literature search was conducted using PubMed, Embase, CENTRAL, and abstracts published in the SIOP meetings. Studies that described the outcome of patients of LCH being treated with vemurafenib, alone or in combination, were included. A total of 416 studies were screened, and after applying exclusion criteria, 22 studies (n = 107) were included in the final analysis. The first-line therapy was prednisolone plus vinblastine for most patients (n = 92, 86%), and vemurafenib was started upfront in 3 patients (3%). The median time to first clinical response with vemurafenib was one week. The median time to best response was 5.25 months. Out of 107 patients, 62 patients (58%) had ultimately no active disease (NAD) while 39 (36%) had active disease better (ADB), making the overall response rate (ORR) of 101/107, ie, 94.4% (CI 0.88; 0.98). The main adverse effects of vemurafenib were rash or photosensitivity (47%) and other cutaneous adverse events (15%). Vemurafenib is highly efficacious and safe in the treatment of refractory LCH; however, the timing of its commencement and duration of therapy is yet to be established. Larger prospective collaborative trials are needed to answer the appropriate treatment duration and effective maintenance therapy approach.

A 13-Year-Old Male With Left Eye Swelling

A 13-year-old male presented with a 10-day history of left eye swelling and pain. These symptoms prompted presentation to the emergency department. He had no significant past medical history and no preceding fevers or chills. He was found on examination of the eyes and the orbit to have left supraorbital erythema, edema, and pain with upward and medial gaze. Examination of the globe, fundus, and visual fields were normal. His white blood cell count was 6.2 (x1000/mm3) with an erythrocyte sedimentation rate of 4 (mm/hr). Diagnostic endoscopic biopsy was performed. Here we present this case alongside clinical reasoning and diagnostic evaluation with relevant input from respective experts. This case discussion reviews the final diagnosis, as well as the corresponding evaluation and management. Diagnostic algorithms based on literature review and clinical experience are also included.

Clinical and magnetic resonance imaging feature differences between solitary and multiple type Langerhans cell histiocytosis involving the craniofacial bone

PURPOSE

To investigate the clinical and contrast-enhanced magnetic resonance imaging (MRI) features of craniofacial bone Langerhans cell histiocytosis (LCH) and discuss the differences between a solitary lesion group (SLG) and multiple lesions group (MLG).

METHOD

This study included 22 consecutive patients with pathologically proven LCH who underwent contrast-enhanced MRI. The clinical data and MRI features were retrospectively assessed.

RESULTS

The mean patient age was 5 years, and 15 patients were male. The frontal bone was the most frequently affected bone. Ten and 12 patients were classified into the SLG and the MLG, respectively. The following MRI features were observed in >50% cases: T1WI hyperintensity in 15 (68%) cases, T2WI hyperintensity in 16 (73%) cases, bulging sign in 18 (82%) cases, concentric or eccentric soft tissue mass formation in 13 (59%) cases, soft tissue edema in 16 (73%) cases, any grade of bone marrow edema in 16 (73%) cases, surrounding bone enhancement in 17 (77%) cases, and surrounding soft tissue enhancement in 16 (73%) cases. Patient age was significantly higher in the SLG than that in the MLG (P = 0.0014). Perilesional bone marrow edema and enhancement were significantly more prominent in the SLG than in the MLG (P = 0.032, P = 0.040).

CONCLUSIONS

Contrast-enhanced MRI showed additional significant findings of mainly the surrounding details. Older age, extensive bone marrow edema, and enhancement may indicate solitary-type LCH rather than multiple-type LCH. These differences may help distinguish between solitary- and multiple-type LCH, which have different treatment strategies.