ALK-positive histiocytosis: a new clinicopathologic spectrum highlighting neurologic involvement and responses to ALK inhibition

ALK-positive histiocytosis is a rare subtype of histiocytic neoplasm first described in 2008 in three infants with multisystemic disease involving the liver and hematopoietic system. This entity has subsequently been documented in case reports and series to occupy a wider clinicopathologic spectrum with recurrent KIF5B-ALK fusions. The full clinicopathologic and molecular spectra of ALK-positive histiocytosis remain, however, poorly characterized. Here, we describe the largest study of ALK-positive histiocytosis to date, with detailed clinicopathologic data of 39 cases, including 37 cases with confirmed ALKrearrangements. The clinical spectrum comprised distinct clinical phenotypic groups: infants with multisystemic disease with liver and hematopoietic involvement, as originally described (Group 1A: 6/39), other patients with multisystemic disease (Group 1B: 10/39), and patients with single-system disease (Group 2: 23/39). Nineteen patients of the entire cohort (49%) had neurologic involvement (seven and twelve from Groups 1B and 2, respectively). Histology included classic xanthogranuloma features in almost one third of cases, whereas the majority displayed a more densely cellular, monomorphic appearance without lipidized histiocytes but sometimes more spindled or epithelioid morphology. Neoplastic histiocytes were positive for macrophage markers and often conferred strong expression of phosphorylated-ERK, confirming MAPK pathway activation. KIF5B-ALK fusions were detected in 27 patients, while CLTC-ALK, TPM3-ALK, TFG-ALK, EML4-ALK and DCTN1-ALK fusions were identified in single cases. Robust and durable responses were observed in 11/11 patients treated with ALK inhibition, ten with neurologic involvement. This study presents the existing clinicopathologic and molecular landscape of ALK-positive histiocytosis, and provides guidance for the clinical management of this emerging histiocytic entity.Molecular tumour pathology - and tumour genetic

The Pediatric Colorectal and Pelvic Learning Consortium (PCPLC): rationale, infrastructure, and initial steps

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Computational Methods for Complex Stochastic Systems: A Review of Some Alternatives to MCMC.

We consider analysis of complex stochastic models based upon partial information. MCMC and reversible jump MCMC are often the methods of choice for such problems, but in some situations they can be difficult to implement; and suffer from problems such as poor mixing, and the difficulty of diagnosing convergence. Here we review three alternatives to MCMC methods: importance sampling, the forward-backward algorithm, and sequential Monte Carlo (SMC). We discuss how to design good proposal densities for importance sampling, show some of the range of models for which the forward-backward algorithm can be applied, and show how resampling ideas from SMC can be used to improve the efficiency of the other two methods. We demonstrate these methods on a range of examples, including estimating the transition density of a diffusion and of a discrete-state continuous-time Markov chain; inferring structure in population genetics; and segmenting genetic divergence data

Does presence of a VACTERL anomaly predict an associated gynecologic anomaly in females with anorectal malformations?: A Pediatric Colorectal and Pelvic Learning Consortium Study.

BACKGROUND: VACTERL association is defined by the presence of 3 or more anomalies in any of the following systems: vertebral, anorectal, cardiac, trachea-esophageal, renal, or limb. This study hypothesized that the presence of VACTERL association would correlate with an increased risk of gynecologic anomalies in patients with anorectal malformation (ARM). METHODS: This study is a cross-sectional, retrospective analysis from the prospectively collected, multicenter registry of the Pediatric Colorectal and Pelvic Learning Consortium (PCPLC). The 834 female patients with ARM who were enrolled in the registry by January 1, 2020 were included in this study. The relationship of VACTERL association with presence of a gynecologic anomaly was evaluated with Fisher's exact test. The relationship of each VACTERL system with presence of a gynecologic anomaly was assessed in patients with cloaca, rectovestibular fistulas and rectoperineal fistulas. P-values reported were based on a 2-sided alternative and considered significant when less than 0.05. RESULTS: 834 patients with ARM underwent VACTERL screening and gynecologic evaluation with the three most common subtypes being cloaca (n = 215, 25.8%), rectovestibular fistula (n = 191, 22.9%) and rectoperineal fistula (n = 194, 23.3%). A total of 223 (26.7%) patients with ARM had gynecologic anomalies. VACTERL association was seen in 380 (45.6%) of patients with ARM. Gynecologic anomalies were present in 149 (39.1%) vs. 74 (16.3%) of subjects with vs. without VACTERL association (p < 0.001). VACTERL association did not significantly increase the risk of gynecologic anomaly in patients with cloaca and VACTERL (n = 88, 61.5%) vs. cloaca without VACTERL (n = 39, 54.2% p = 0.308). VACTERL association increased the risk of gynecologic anomalies in patients with rectoperineal fistulas (n = 7, 14.9% vs n = 9, 6.1% p = 0.014) and rectovestibular fistulas (n = 19, 31.1% vs. n = 13, 10.0% p<0.001). In patients with ARM who had a VACTERL association, when one of the associated anomalies was renal, there was an even higher risk of having an associated gynecologic anomaly (n = 138, 44.2% vs. n = 85, 16.3% p<0.001). CONCLUSIONS: VACTERL association in patients with rectoperineal and rectovestibular fistulas correlates with an increased risk of gynecologic anomalies. The presence of VACTERL associated findings, especially renal, should prompt a thorough evaluation of the gynecologic system. LEVEL OF EVIDENCE: III. Retrospective comparative study

Inhaled non-steroidal polyphenolic alternatives for anti-inflammatory combination therapy

The inhaled corticosteroids are considered the first line of defence for the treatment of persistent asthma and COPD in adults and children. However, clinically, up to 50% of asthmatics and the majority of COPD patients have been reported to respond sub-optimally to inhaled corticosteroid therapy. Therefore, reduced responsiveness to corticosteroids or in extreme cases, a complete lack of response even to high doses, is becoming a growing cause of concern to the medical community. This work therefore seeks to circumvent the problem via pioneering an inhalable non-steroidal polyphenolic dry powder combination comprising curcumin, quercetin and trans-resveratrol from the phenolic acid, flavonoid and stilbene classes respectively, for benign anti-inflammatory therapy (without the corticosteroid-linked side effects). The optimized L-leucine-containing spray-dried powder was partially crystalline and moisture-resistant, and the powder particles were of respirable-size (d50 of ~1.95 ± 0.03 μm), corrugated and porous. When dispersed via an Aerolizer® inhaler at 60 l/min, the powder showed concomitant in-vitro deposition with robust FPFs of ~44%. Significant improvements to the drug release rate and extent were also achieved. Favorably, the optimized formulation was comparable to the mainstream corticosteroids, budesonide and beclomethasone dipropionate, and more potent than an ivy leaves extract preparation, in inhibiting GM-CSF release from inflamed A549 cells. Potentially, this corticosteroid-sparing inhaled alternative might be a potent yet safer treatment option for juvenile, corticosteroid-resistant, or even mainstream patients.ASTAR (Agency for Sci., Tech. and Research, S’pore