Complex Compound Inheritance of Lethal Lung Developmental Disorders Due to Disruption of the TBX-FGF Pathway.

Primary defects in lung branching morphogenesis, resulting in neonatal lethal pulmonary hypoplasias, are incompletely understood. To elucidate the pathogenetics of human lung development, we studied a unique collection of samples obtained from deceased individuals with clinically and histopathologically diagnosed interstitial neonatal lung disorders: acinar dysplasia (n = 14), congenital alveolar dysplasia (n = 2), and other lethal lung hypoplasias (n = 10). We identified rare heterozygous copy-number variant deletions or single-nucleotide variants (SNVs) involving TBX4 (n = 8 and n = 2, respectively) or FGF10 (n = 2 and n = 2, respectively) in 16/26 (61%) individuals. In addition to TBX4, the overlapping ∼2 Mb recurrent and nonrecurrent deletions at 17q23.1q23.2 identified in seven individuals with lung hypoplasia also remove a lung-specific enhancer region. Individuals with coding variants involving either TBX4 or FGF10 also harbored at least one non-coding SNV in the predicted lung-specific enhancer region, which was absent in 13 control individuals with the overlapping deletions but without any structural lung anomalies. The occurrence of rare coding variants involving TBX4 or FGF10 with the putative hypomorphic non-coding SNVs implies a complex compound inheritance of these pulmonary hypoplasias. Moreover, they support the importance of TBX4-FGF10-FGFR2 epithelial-mesenchymal signaling in human lung organogenesis and help to explain the histopathological continuum observed in these rare lethal developmental disorders of the lung.

The Emergence of Zoonotic Onchocerca lupi Infection in the United States--A Case-Series.

This case-series describes the 6 human infections with Onchocerca lupi, a parasite known to infect cats and dogs, that have been identified in the United States since 2013. Unlike cases reported outside the country, the American patients have not had subconjunctival nodules but have manifested more invasive disease (eg, spinal, orbital, and subdermal nodules). Diagnosis remains challenging in the absence of a serologic test. Treatment should be guided by what is done for Onchocerca volvulus as there are no data for O. lupi. Available evidence suggests that there may be transmission in southwestern United States, but the risk of transmission to humans is not known. Research is needed to better define the burden of disease in the United States and develop appropriately-targeted prevention strategies.

Late Onset Hypomorphic RAG2 Deficiency Presentation with Fatal Vaccine-Strain VZV Infection.

PURPOSE: Hypomorphic mutations in RAG1 and RAG2 are associated with significant clinical heterogeneity and symptoms of immunodeficiency or autoimmunity may be late in appearance. As a result, immunosuppressive medications may be introduced that can have life-threatening consequences. We describe a previously healthy 13-month-old girl presenting with rash and autoimmune hemolytic anemia, while highlighting the importance of vigilance and consideration of an underlying severe immunodeficiency disease prior to instituting immunosuppressive therapy. METHODS: Given clinical deterioration of the patient and a temporal association with recently administered vaccinations, virus genotyping was carried out via 4 real-time Forster Resonance Energy Transfer PCR protocols targeting vaccine-associated single nucleotide polymorphisms. Genomic DNA was extracted from whole blood and analyzed via the next-generation sequencing method of sequencing-by-synthesis. Immune function studies included immunophenotyping of peripheral blood lymphocytes, mitogen-induced proliferation and TLR ligand-induced production of TNFα. Analysis of recombination activity of wild-type and mutant RAG2 constructs was performed. RESULTS: Virus genotyping revealed vaccine-strain VZV, mumps, and rubella. Next-generation sequencing identified heterozygosity for RAG2 R73H and P180H mutations. Profound lymphopenia was associated with intense corticosteroid therapy, with some recovery after steroid reduction. Residual, albeit low, RAG2 protein activity was demonstrated. CONCLUSIONS: Because of the association of RAG deficiency with late-onset presentation and autoimmunity, live virus vaccination and immunosuppressive therapies are often initiated and can result in negative consequences. Here, hypomorphic RAG2 mutations were linked to disseminated vaccine-strain virus infections following institution of corticosteroid therapy for autoimmune hemolytic anemia.

Intrapulmonary vascular shunt pathways in alveolar capillary dysplasia with misalignment of pulmonary veins.

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a lethal neonatal lung disease characterised by severe pulmonary hypertension, abnormal vasculature and intractable hypoxaemia. Mechanisms linking abnormal lung vasculature with severe hypoxaemia in ACD/MPV are unknown. We investigated whether bronchopulmonary anastomoses form right-to-left shunt pathways in ACD/MVP. We studied 2 infants who died of ACD/MPV postmortem with direct injections of coloured ink into the pulmonary artery, bronchial artery and pulmonary veins. Extensive histological evaluations included serial sectioning, immunostaining and 3-dimensional reconstruction demonstrated striking intrapulmonary vascular pathways linking the systemic and pulmonary circulations that bypass the alveolar capillary bed. These data support the role of prominent right-to-left intrapulmonary vascular shunt pathways in the pathophysiology of ACD/MPV.

A pediatric case of mammary analogue secretory carcinoma within the parotid.

Mammary analogue secretory carcinoma (MASC) is a recently described entity in the differential diagnosis of salivary gland tumors. It is notable for a characteristic t(12;15)(p13;q25) translocation that results in a unique fusion protein, ETV6-NTRK3. While several studies have retrospectively identified this translocation in cases previously diagnosed as a different salivary malignancy, there have been relatively few cases where this translocation was identified on initial pathology results, and fewer still in a pediatric population. We present a case of a 15 year old female with a slowly enlarging, painless, left facial mass. MRI demonstrated a cystic mass extending into the deep lobe of the parotid, and she underwent parotidectomy. The tumor cells stained positive for S100 and CK19. ETV6 translocation was present, confirming the diagnosis. Mammary analogue secretory carcinoma is a recently described tumor of the salivary glands, which often masquerades as more common primary salivary gland tumors and cysts. More research is needed to characterize the typical behavior of this neoplasm and the optimal treatment regimen. With identification of its characteristic translocation, mammary analogue secretory carcinoma can be easily differentiated from its more prevalent counterparts, and should therefore remain within the differential of the pathologist and head and neck surgeon.

Compound heterozygous CORO1A mutations in siblings with a mucocutaneous-immunodeficiency syndrome of epidermodysplasia verruciformis-HPV, molluscum contagiosum and granulomatous tuberculoid leprosy.

PURPOSE: Coronin-1A deficiency is a recently recognized autosomal recessive primary immunodeficiency caused by mutations in CORO1A (OMIM 605000) that results in T-cell lymphopenia and is classified as T(-)B(+)NK(+)severe combined immunodeficiency (SCID). Only two other CORO1A-kindred are known to date, thus the defining characteristics are not well delineated. We identified a unique CORO1A-kindred. METHODS: We captured a 10-year analysis of the immune-clinical phenotypes in two affected siblings from disease debut of age 7 years. Target-specific genetic studies were pursued but unrevealing. Telomere lengths were also assessed. Whole exome sequencing (WES) uncovered the molecular diagnosis and Western blot validated findings. RESULTS: We found the compound heterozygous CORO1A variants: c.248_249delCT (p.P83RfsX10) and a novel mutation c.1077delC (p.Q360RfsX44) (NM_007074.3) in two affected non-consanguineous siblings that manifested as absent CD4CD45RA(+) (naïve) T and memory B cells, low NK cells and abnormally increased double-negative (DN) ϒδ T-cells. Distinguishing characteristics were late clinical debut with an unusual mucocutaneous syndrome of epidermodysplasia verruciformis-human papilloma virus (EV-HPV), molluscum contagiosum and oral-cutaneous herpetic ulcers; the older female sibling also had a disfiguring granulomatous tuberculoid leprosy. Both had bilateral bronchiectasis and the female died of EBV+ lymphomas at age 16 years. The younger surviving male, without malignancy, had reproducibly very short telomere lengths, not before appreciated in CORO1A mutations. CONCLUSION: We reveal the third CORO1A-mutated kindred, with the immune phenotype of abnormal naïve CD4 and DN T-cells and newfound characteristics of a late/hypomorphic-like SCID of an EV-HPV mucocutaneous syndrome with also B and NK defects and shortened telomeres. Our findings contribute to the elucidation of the CORO1A-SCID-CID spectrum.

Multicentric Castleman disease presenting with fever.

Multicentric Castleman disease (MCD) is a rare lymphoproliferative disorder that usually manifests with nonspecific symptoms, including fever and lymphadenopathy. Treatment of pediatric MCD varies greatly. A 21-month-old child was diagnosed with MCD after presenting with fever. He had incomplete response to initial therapy directed at interleukin-6, but improved with subsequent chemotherapy.

Pituitary blastoma: a pathognomonic feature of germ-line DICER1 mutations.

Individuals harboring germ-line DICER1 mutations are predisposed to a rare cancer syndrome, the DICER1 Syndrome or pleuropulmonary blastoma-familial tumor and dysplasia syndrome [online Mendelian inheritance in man (OMIM) #601200]. In addition, specific somatic mutations in the DICER1 RNase III catalytic domain have been identified in several DICER1-associated tumor types. Pituitary blastoma (PitB) was identified as a distinct entity in 2008, and is a very rare, potentially lethal early childhood tumor of the pituitary gland. Since the discovery by our team of an inherited mutation in DICER1 in a child with PitB in 2011, we have identified 12 additional PitB cases. We aimed to determine the contribution of germ-line and somatic DICER1 mutations to PitB. We hypothesized that PitB is a pathognomonic feature of a germ-line DICER1 mutation and that each PitB will harbor a second somatic mutation in DICER1. Lymphocyte or saliva DNA samples ascertained from ten infants with PitB were screened and nine were found to harbor a heterozygous germ-line DICER1 mutation. We identified additional DICER1 mutations in nine of ten tested PitB tumor samples, eight of which were confirmed to be somatic in origin. Seven of these mutations occurred within the RNase IIIb catalytic domain, a domain essential to the generation of 5p miRNAs from the 5' arm of miRNA-precursors. Germ-line DICER1 mutations are a major contributor to PitB. Second somatic DICER1 "hits" occurring within the RNase IIIb domain also appear to be critical in PitB pathogenesis.

[Neuroendocrine cell hyperplasia of infancy--case study]. / Neuroendokrynna hiperplazja wieku niemowlecego - opis przypadku.

Neuroendocrine cell hyperplasia of infancy is a rare form of children's interstitial lung disease recognised usually in infancy and in children younger than two years old. The typical clinical scenario, such as chest retractions, tachypnoea, hypoxaemia, crackles, characteristic changes in high-resolution computed tomography and histological examination of the lung parenchyma, is the cornerstone for diagnosis. In the article, the authors describe clinical manifestation of neuroendocrine cell hyperplasia and a present case of an infant with this rare interstitial lung disease.

A rare cause of testicular torsion: Lymphocytic infiltration in an adolescent with recently diagnosed B-ALL.

Testicular torsion is a commonly encountered medical emergency in children. A 10-year-old boy with diagnostically confirmed leukemia presented with new onset testis swelling. Scrotal ultrasound showed absent blood flow on the left, consistent with acute testicular torsion. The patient underwent left orchiectomy due to the testis being unsalvageable. Later pathology confirmed lymphoblastic infiltrates. A malignancy of the testicles is rarely associated with torsion and, in the setting of leukemia, suggests widespread disease. Due to the risk of scrotal violation, an inguinal approach is preferable for surgical exploration of the testicles in patients with a history of leukemia.

An unusual presentation of neonatal rhabdomyosarcoma: a case report.

A full-term infant with an unremarkable prenatal course presented at birth with a large midline facial mass and smaller masses in the head and neck. In addition, multiple diffuse flesh-colored nodules spread along all the upper and lower limbs. An extensive evaluation to cover a broad differential diagnosis of infectious, lymphatic/vascular, and oncologic etiology was undertaken. The initial suspicion was confirmed by biopsy of the skin lesion as congenital alveolar rhabdomyosarcoma (RMS). RMS is the most common soft tissue sarcoma that occurs in childhood. However, neonatal RMS is exceedingly rare. The infant's initial treatment included vincristine, dactinomycin, and cyclophosphamide in addition to salvage ifosfamide and etoposide, which were dose-adjusted for age. Herein, we present a case of an infant with RMS who showed initial improvement before relapsing and succumbing to her disease at 5 months of age. A review of the limited literature available on this rare condition and newer treatment regimens with improved mortality rates is performed.

Rapid and progressive pulmonary fibrosis in 2 families with DNA repair deficiencies of undetermined etiology.

Known genetic causes of pediatric interstitial lung disease include disorders of surfactant metabolism, telomerase, and DNA repair. We report 4 children from 2 families with rapidly progressive and fatal pulmonary fibrosis. A novel DNA repair defect unrelated to the ataxia-telangiectasia mutated gene was found in 1 child from each family.

Undifferentiated sarcoma of the liver: a single institution experience using a uniform treatment approach.

Undifferentiated (embryonal) sarcoma of the liver is a rare malignant tumor, most commonly seen in children aged 6 to 10 years. Previously believed to carry a poor prognosis, more recent reports indicate that treatment regimens combining surgical resection and adjuvant chemotherapy can yield long-term, disease-free survival. In this study, we review 5 pediatric patients with undifferentiated sarcoma of the liver treated with a uniform approach of resection followed by adjuvant chemotherapy and radiation when indicated. All 5 patients are disease free in their first remission at a median of 53 months.

Extending the phenotypes associated with DICER1 mutations.

DICER1 is crucial for embryogenesis and early development. Forty different heterozygous germline DICER1 mutations have been reported worldwide in 42 probands that developed as children or young adults, pleuropulmonary blastoma (PPB), cystic nephroma (CN), ovarian sex cord-stromal tumors (especially Sertoli-Leydig cell tumor [SLCT]), and/or multinodular goiter (MNG). We report DICER1 mutations in seven additional families that manifested uterine cervix embryonal rhabdomyosarcoma (cERMS, four cases) and primitive neuroectodermal tumor (cPNET, one case), Wilms tumor (WT, three cases), pulmonary sequestration (PS, one case), and juvenile intestinal polyp (one case). One carrier developed (age 25 years) a pleomorphic sarcoma of the thigh; another carrier had transposition of great arteries (TGA). These observations show that cERMS, cPNET, WT, PS, and juvenile polyps fall within the spectrum of DICER1-related diseases. DICER1 appears to be the first gene implicated in the etiology of cERMS, cPNET, and PS. Young adulthood sarcomas and perhaps congenital malformations such as TGA may also be associated.

Paediatric interstitial lung disease: classification and definitions.

Classifications of interstitial (diffuse) lung disease in adults and children have undergone significant revision in recent years, with advances in our understanding of new entities and the biology and prognostic significance of certain histologic patterns. The contributions of the European Respiratory Society Task Force on Interstitial Lung Disease in Children and the North American Children's Interstitial Lung Disease Group are reviewed, and a clinicopathologic classification of paediatric diffuse lung disease is summarized. Clinical characteristics and histologic definitions are also presented for selected entities within this classification, specifically, acinar dysgenesis, congenital alveolar dysplasia, alveolar capillary dysplasia with misalignment of pulmonary veins, abnormalities of alveolar growth, pulmonary interstitial glycogenosis, neuroendocrine cell hyperplasia of infancy, surfactant dysfunction disorders, obliterative bronchiolitis, hypersensitivity pneumonitis, and immunologic disorders. More uniform application of this diagnostic terminology in the future will allow more meaningful comparisons of different patient populations, radiologic-pathologic correlation, and development of disease-specific therapeutic strategies.

Ground glass and fibrotic change in children with surfactant protein C dysfunction mutations.

INTRODUCTION: Therapeutics exist to treat fibrotic lung disease in adults, but these have not been investigated in children. Defining biomarkers for pediatric fibrotic lung disease in children is crucial for clinical trials. Children with surfactant protein C (SFTPC) dysfunction mutations develop fibrotic lung disease over time. We evaluated chest computed tomography (CT) changes over time in children with SFTPC dysfunction mutations. METHODS: We performed an institutional review board-approved retrospective review of children with SFTPC dysfunction mutations. We collected demographic and clinical information. Chest CT scans were evaluated using visual and computerized scores. Chest CT scores and pulmonary function tests were reviewed. RESULTS: Eleven children were included. All children presented in infancy and four children suffered from respiratory failure requiring mechanical ventilation. Those who performed pulmonary function tests had stable forced vital capacities over time by percent predicted, but increased forced vital capacity in liters. CT findings evolved over time in most patients with earlier CT scans demonstrating ground glass opacities and later CT scans with more fibrotic features. In a pilot analysis, data-driven textural analysis software identified fibrotic features in children with SFTPC dysfunction that increased over time and correlated with visual CT scores. DISCUSSION: We describe 11 children with SFTPC dysfunction mutations. Increases in forced vital capacity over time suggest that these children experience lung growth and that therapeutic intervention may maximize lung growth. Ground glass opacities are the primary early imaging findings while fibrotic features dominate later. CT findings suggest the development of and increases in fibrotic features that may serve as potential biomarkers for antifibrotic therapeutic trials.

IgA nephropathy presenting with renal failure and pulmonary hemorrhage.

Pulmonary renal syndromes are unusual, but frequently life-threatening manifestations of a distinct group of disorders in the pediatric age group. Although IgA nephropathy is a common cause of hematuria, it is an extremely rare cause of pulmonary renal syndrome, causing high mortality, and has mostly been reported in adult patients. We describe the youngest patient with this presentation reported to date, a 14-year-old male, who presented with end stage renal disease and pulmonary hemorrhage and was found to have IgA nephropathy by renal biopsy and pulmonary capillaritis by open lung biopsy. His lung disease was successfully treated with immunosuppressive medications. Despite this being a rare manifestation of IgA nephropathy, clinicians need to be aware of this presentation as it is potentially fatal, but amenable to aggressive immunosuppression.