Alterations in ALK/ROS1/NTRK/MET drive a group of infantile hemispheric gliomas

Infant gliomas have paradoxical clinical behavior compared to those in children and adults: low-grade tumors have a higher mortality rate, while high-grade tumors have a better outcome. However, we have little understanding of their biology and therefore cannot explain this behavior nor what constitutes optimal clinical management. Here we report a comprehensive genetic analysis of an international cohort of clinically annotated infant gliomas, revealing 3 clinical subgroups. Group 1 tumors arise in the cerebral hemispheres and harbor alterations in the receptor tyrosine kinases ALK, ROS1, NTRK and MET. These are typically single-events and confer an intermediate outcome. Groups 2 and 3 gliomas harbor RAS/MAPK pathway mutations and arise in the hemispheres and midline, respectively. Group 2 tumors have excellent long-term survival, while group 3 tumors progress rapidly and do not respond well to chemoradiation. We conclude that infant gliomas comprise 3 subgroups, justifying the need for specialized therapeutic strategies.

Infant gliomas behave differently to their childhood or adult counterparts. Here, the authors perform a large-scale genetic analysis of these tumours, revealing genetic alterations which may offer therapeutic opportunities.

Contribution of Altered Endocannabinoid System to Overactive mTORC1 Signaling in Focal Cortical Dysplasia

Alterations of the PI3K/Akt/mammalian target of rapamycin complex 1 (mTORC1) signaling pathway are causally involved in a subset of malformations of cortical development (MCDs) ranging from focal cortical dysplasia (FCD) to hemimegalencephaly and megalencephaly. These MCDs represent a frequent cause of refractory pediatric epilepsy. The endocannabinoid system -especially cannabinoid CB₁ receptor- exerts a neurodevelopmental regulatory role at least in part via activation of mTORC1 signaling. Therefore, we sought to characterize the possible contribution of endocannabinoid system signaling to FCD. Confocal microscopy characterization of the CB₁ receptor expression and mTORC1 activation was conducted in FCD Type II resection samples. FCD samples were subjected to single nucleotide polymorphism screening for endocannabinoid system elements, as well as CB₁ receptor gene sequencing. Cannabinoid CB₁ receptor levels were increased in FCD with overactive mTORC1 signaling. CB₁ receptors were enriched in phospho-S6-positive cells including balloon cells (BCs) that co-express aberrant markers of undifferentiated cells and dysplastic neurons. Pharmacological regulation of CB₁ receptors and the mTORC1 pathway was performed in fresh FCD-derived organotypic cultures. HU-210-evoked activation of CB₁ receptors was unable to further activate mTORC1 signaling, whereas CB₁ receptor blockade with rimonabant attenuated mTORC1 overactivation. Alterations of the endocannabinoid system may thus contribute to FCD pathological features, and blockade of cannabinoid signaling might be a new therapeutic intervention in FCD.

Management and outcome of children and adolescents with non-medulloblastoma CNS embryonal tumors in Spain: room for improvement in standards of care

Non-medulloblastoma CNS embryonal tumors (former PNET/Pineoblastomas) are aggressive malignancies with poor outcome that have been historically treated with medulloblastoma protocols. The purpose of this study is to present a tumor-specific, real-world data cohort of patients with CNS-PNET/PB to analyze quality indicators that can be implemented to improve the outcome of these patients. Patients 0-21 years with CNS-PNET treated in eight large institutions were included. Baseline characteristics, treatment and outcome [progression-free and overall survival (PFS and OS respectively)] were analyzed. From 2005 to 2014, 43 patients fulfilled entry criteria. Median age at diagnosis was 3.6 years (range 0.0-14.7). Histology was pineoblastoma (9%), ependymoblastoma (5%), ETANTR (7%) and PNET (77%). Median duration of the main symptom was 2 weeks (range 0-12). At diagnosis, 28% presented with metastatic disease. Seventeen different protocols were used on frontline treatment; 44% had gross total resection, 42% craniospinal radiotherapy, 86% chemotherapy, and 33% autologous hematopoietic stem cell transplantation (aHSCT). Median follow-up for survivors was 3.5 years (range 1.7-9.3). 3-year PFS was 31.9% (95% CI 17-47%) and OS 35.1% (95% CI 20-50%). Age, extent of resection and radiotherapy were prognostic of PFS and OS in univariate analysis (p < 0.05). Our series shows a dismal outcome for CNS-PNET, especially when compared to patients included in clinical trials. Establishing a common national strategy, implementing referral circuits and collaboration networks, and incorporating new molecular knowledge into routine clinical practice are accessible measures that can improve the outcome of these patients.

Vulvar fetal rhabdomyoma mimicking 46XX sex differentiation disorder

Rhabdomiomas are rare mesenchymal benign tumors of striated muscle origin. Setting aside the cardiac (most atrial) rhabdomiomas typically associated to neurocutaneous syndromes (tuberous sclerosis), extracardiac rhabdomyomas appear clinically as a subcutaneous nodule or as a submucosal polypoid lesion. Among them, three main histologic subtypes can be differentiated on the basis of the degree of tumor differentiation: 1) fetal rhabdomioma, usually diagnosed during childhood and almost exclusively located in the in the head and neck region with rare reports in other locations; 2) adult rhabdomioma; and 3) genital rhabdomioma, reported to occur in the lower genital tract of young and middle-aged women and, exceptionally, in children (5).

Desmoplastic Trichoepithelioma: An Infrequent Entity not to be Missed: Report of Two Cases

Desmoplastic trichoepitheliomas are rare benign tumors with follicular differentiation. They have rarely been described in children. We report two children with this uncommon condition.

A phase I/II trial of interleukin-15--stimulated natural killer cell infusion after haplo-identical stem cell transplantation for pediatric refractory solid tumors

BACKGROUND AIMS

Preliminary data suggest that T-cell-depleted haplo-identical stem cell transplantation (haplo-SCT) has a clinically beneficial allograft-versus-tumor effect associated with natural killer (NK) cell immune reconstitution.

METHODS

This phase I/II trial descriptively evaluates the feasibility of interleukin (IL)-15-stimulated NK cell infusion after haplo-SCT in pediatric patients with refractory solid tumors.

RESULTS

Six patients received an IL-15-stimulated NK cell infusion at 30 days after haplo-SCT. The mean number of infused NK cells per product was 11.3 × 10(6)/kg (range, 3-27 × 10(6)/kg). The T-cell count was <1 × 10(3)/kg in all patients (range, 0-0.75 × 10(3)/kg). No toxic effects related to IL-15--stimulated NK cell infusion were observed. Four of the six patients showed a clinical response (one achieved very good partial remission, two achieved partial remission and one had stable disease). One patient had progressive disease, and the response was not evaluated in the remaining patient. After a median follow-up period of 310 days, all patients had died: four of cancer relapse, one of cancer-associated thrombotic micro-angiopathy and one of acute graft-versus-host disease.

CONCLUSIONS

The adoptive transfer of allogeneic IL-15--stimulated NK cells might be feasible and safe in heavily pretreated pediatric patients with refractory solid tumors, though the advanced stage of disease and toxic effects of haplo-SCT may limit the efficacy of NK cell infusion in this population.

Hemicerebellitis: Report of three paediatric cases and review of the literature

Acute inflammation of a single cerebellar hemisphere (hemicerebellitis) is a rare disorder of unknown origin. The clinical presentation is mainly characterized by headache, ataxia, dysmetria, and vomiting. In addition, some children may develop severe intracranial hypertension. The neuroimaging of hemicerebellitis raises a challenging differential diagnosis, particularly with posterior fossa tumours. Although there is no standard treatment for hemicerebellitis, its outcome is usually favourable. However, ipsilateral hemicerebellar atrophy develops in up to half of cases, and a minority of children may show persisting fine motor and/or neurocognitive sequelae. In this article, we contribute with three new reports and review a total of 35 cases of hemicerebellitis.

In vitro Natural Killer Cell Immunotherapy for Medulloblastoma

How the immune system attacks medulloblastoma (MB) tumors effectively is unclear, although natural killer (NK) cells play an important role in immune defense against tumor cells. Interactions between receptors on NK cells and ligands expressed by tumor cells are critical for tumor control by immunotherapy. In this study, we analyzed tumor samples from 54 MB patients for expression of major histocompatibility complex class I-related chains A (MICA) and UL16 binding protein (ULPB-2), which are ligands for the NK group 2 member D activatory receptor (NKG2D). The percentage of MICA and ULBP-2 positive cells was higher than 25% in 68% and 6% of MB patients, respectively. A moderate-high intensity of MICA cytoplasmic staining was observed in 46% MB patients and weak ULBP-2 staining was observed in 8% MB patients. No correlation between MICA/ULBP-2 expression and patient outcome was found. We observed that HTB-186, a MB cell line, was moderately resistant to NK cell cytotoxicity in vitro. Blocking MICA/ULBP-2 on HTB-186, and NKG2D receptor on NK cells increased resistance to NK cell lysis in vitro. However, HLA class I blocking on HTB-186 and overnight incubation with IL-15 stimulated NK cells efficiently killed tumor cells in vitro. We conclude that although NKG2D/MICA-ULBP-2 interactions have a role in NK cell cytotoxicity against MB, high expression of HLA class I can protect MB from NK cell cytotoxicity. Even so, our in vitro data indicate that if NK cells are appropriately stimulated, they may have the potential to target MB in vivo.

Systemic juvenile xanthogranuloma with fatal outcome

Juvenile xanthogranuloma is a benign and self-limited disease which usually appears in the skin of children. Visceral involvement has been rarely reported, as has fatal outcome in some affected individuals. We report a case of systemic juvenile xanthogranuloma in a female newborn with mainly skin, bone marrow, and liver involvement, leading to death at the age of 2 months.

Perforating neutrophilic and granulomatous dermatitis of the newborn--a clue to immunodeficiency

We report two newborns with a widespread cutaneous eruption consisting of discrete papules which evolved into vesicles, pustules, crusts, and ulcers. These healed over a 2-week period with scarring. Histopathology showed three main features--histiocytic granulomas, neutrophilic infiltration, and transepidermal elimination of degenerated collagen and debris through hair follicles. Both patients had congenital immunodeficiency. This skin condition of the newborn, with distinct clinical and histopathologic features, is a manifestation of immunodeficiency that has not been previously described.

Erythema dyschromicum perstans in children: a report of 14 cases

BACKGROUND

Erythema dyschromicum perstans (EDP) or ashy dermatosis is a peculiar, slowly progressive, macular hyperpigmentation, which leaves a permanent discoloration. It is an acquired dermatosis that occurs most frequently in Central and South America. EDP usually appears in adults, but some isolated cases and small series have been reported in prepubertal children.

METHODS

A retrospective review of cases of EDP in 10-year-old children or younger, attended in a pediatric hospital between 1990 and 2003.

RESULTS

We present 14 cases of EDC in children 10 years and younger. With an additional 25 cases reported so far in the English language literature, a total of 39 children have been described. Unlike adult patients, who are most commonly of Hispanic origin, children with EDP are usually Caucasian. Other important facts in children with EDP are the absence of consistent trigger factors and an eventual improvement or resolution of the lesions in 50% of prepubertal patients.

CONCLUSION

We suggest that EDP is a distinctive clinical entity, different from lichen planus and lichen planus pigmentosus, which may be identical to the so-called idiopathic eruptive macular pigmentation.

Rabdomiosarcoma botrioides congénito de vulva

Rhabdomyosarcoma is the most frequent malignant soft tissue tumor in pediatric patients; however, the vulvar location and congenital appearance are exceptional. We present the case of a newborn girl with botryoid rhabdomyosarcoma of the vulva, treated with chemotherapy, conservative surgery and autologous transplant. Botryoid rhabdomyosarcoma is a variation of embryonal rhabdomyosarcoma that typically grows in mucosa-lined hollow organs, from where it can spread to the body surface. The treatment of botryoid rhabdomyosarcoma in the genito-urinary area is based on polychemotherapy, and it can be complemented with radiotherapy and conservative surgery if necessary, thus resulting in an excellent prognosis and few long-term functional sequelae.

Extensive speckled lentiginous nevus associated with giant congenital melanocytic nevus: an unusual example of twin spotting?

A 15-year-old boy had an unusual combination of giant congenital melanocytic nevus on his back and a large speckled lentiginous nevus arranged in a checkerboard pattern on the dorsal and lateral aspects of his trunk. The two pigmentary nevi showed distinguishing features both clinically and histopathologically. The speckled lentiginous nevus was not noted at birth but became visible during childhood. We hypothesize that this uncommon co-occurrence may represent a further example of twin spotting and may be categorized as a new, distinct type of phacomatosis.

Erythema multiforme in a neonate

We describe a case of erythema multiforme in a 2-week-old boy. He had no remarkable antecedents, and a polymerase chain reaction-based technique failed to detect herpes simplex virus DNA in the skin biopsy specimen. To our knowledge, only one previous biopsy-proven case of erythema multiforme during the neonatal period has been reported.