Unusual genetic aberrations including a deletion of KLF6 tumor suppressor gene revealed by integrated cytogenetic approaches in a pediatric ewing sarcoma.

Ewing sarcoma is the third most common sarcoma in children and young adults. Its characteristic chromosomal rearrangement results in a chimerical EWSR1-ETS transcription factor. Secondary genetic alterations are very common. Membranous expression of CD99 is seen in almost all tumors. We report 2 unusual cytogenetic findings in a pediatric Ewing sarcoma, an insertion of the MIC2 gene encoding CD99 from Xp to 10p and a submicroscopic deletion of the well-known tumor supressor gene KLF6. The latter has not been described previously in pediatric neoplasms. Molecular pathways in tumorigenesis and genetic complexity in cancer are discussed.

Brainstem tegmental necrosis and olivary hypoplasia: raising awareness of a rare neuropathologic correlate of congenital apnea.

This case study describes an instance of death in an early term female newborn with congenital apnea in the clinical setting of multiple congenital anomalies (retrognathia, posteriorly rotated ears, camptodactyly, and arthrogryposis) and prenatal history of polyhydramnios. Postmortem neuropathologic findings were significant for tegmental necrosis in the caudal pons and medulla characterized by a coalescence of microcalcifications accompanied by neuronal loss, axonal spheroids, gliosis, and a concomitant hypoplasia of the inferior olives. This report raises awareness of the rare lethal entity of brainstem tegmental necrosis and olivary hypoplasia and its nosological relationship to the Möbius syndrome in the context of differential diagnosis of congenital apnea owing to central respiratory dysfunction.

Tetrasomy 13q32.2qter due to an apparent inverted duplicated neocentric marker chromosome in an infant with hemangiomas, failure to thrive, laryngomalacia, and tethered cord.

BACKGROUND: Approximately 100 small supernumerary marker chromosomes (sSMCs) with a non-α-satellite neocentromere structure have been reported in the literature. Of the few derived from chromosome 13, five have consisted of inverted duplicated segment 13q32qter. CASE REPORT: We herein describe the sixth case, characterized by genome wide SNP array, conventional cytogenetics and FISH studies. The de novo occurrence of the marker, the poor prognosis and the presence of hemangiomas are consistent with previous cases. CONCLUSION: We hereby expand the clinical spectrum of this rare cytogenetic disorder and suggest a possible mechanism for the pathogenesis of associated congenital vascular malformations.

Pseudotetraploid clone with structural chromosomal rearrangements in a chondromyxoid fibroma: a case report.

Chondromyxoid fibroma is a rare benign tumor accounting for 1-2% of primary bone tumors. Most of the patients are young males in the 2nd and 3rd decades of life. Metaphyses of long bones are predominantly affected. The histology of this tumor is well established, but its genetic mechanism remains poorly characterized. To our knowledge, only 22 abnormal cytogenetic analyses have been reported, and all contained diploidy or near-diploidy karyograms as their primary event, and inv(6)(p25)(q13) and rearrangements involving regions 6p23-25, 6q12-15, and 6q23-27 constituted a recurrent observation. In this report, a pseudotetraploidy tumor clone with multiple numerical and structural aberrations involving 6p23 as well as other chromosomal loci was identified in a chondromyxoid fibroma from the metaphysis of the left fibula of an 18-year-old male, which has not been reported. The finding may relate to the atypical-looking large cells often seen in this benign tumor.

Clonal trisomy 4 cells detected in the ossifying renal tumor of infancy: study of 3 cases.

The ossifying renal tumor of infancy is a rare neoplasm diagnosed in the first 2 years of life, predominantly in boys. The neoplasm is primarily characterized by the presence of a large ossifying component. Its most common mode of presentation is hematuria, and it has a uniformly benign behavior. The karyotypic makeup of the process has not been reported. Thus, a study was undertaken and it allowed demonstration of clonal trisomy 4, which was confirmed by the fluorescent in-situ hybridization-probing of two additional archival formalin-fixed, paraffin-imbedded similar tumors. On the basis of the findings in these three cases, it seems that clonal trisomy 4 may be considered as a characteristic of the tumor, which makes it distinct from any other infantile renal tumor.

Three linked vasculopathic processes characterize Kawasaki disease: a light and transmission electron microscopic study.

BACKGROUND: Kawasaki disease is recognized as the most common cause of acquired heart disease in children in the developed world. Clinical, epidemiologic, and pathologic evidence supports an infectious agent, likely entering through the lung. Pathologic studies proposing an acute coronary arteritis followed by healing fail to account for the complex vasculopathy and clinical course. METHODOLOGY/PRINCIPAL FINDINGS: Specimens from 32 autopsies, 8 cardiac transplants, and an excised coronary aneurysm were studied by light (n=41) and transmission electron microscopy (n=7). Three characteristic vasculopathic processes were identified in coronary (CA) and non-coronary arteries: acute self-limited necrotizing arteritis (NA), subacute/chronic (SA/C) vasculitis, and luminal myofibroblastic proliferation (LMP). NA is a synchronous neutrophilic process of the endothelium, beginning and ending within the first two weeks of fever onset, and progressively destroying the wall into the adventitia causing saccular aneurysms, which can thrombose or rupture. SA/C vasculitis is an asynchronous process that can commence within the first two weeks onward, starting in the adventitia/perivascular tissue and variably inflaming/damaging the wall during progression to the lumen. Besides fusiform and saccular aneurysms that can thrombose, SA/C vasculitis likely causes the transition of medial and adventitial smooth muscle cells (SMC) into classic myofibroblasts, which combined with their matrix products and inflammation create progressive stenosing luminal lesions (SA/C-LMP). Remote LMP apparently results from circulating factors. Veins, pulmonary arteries, and aorta can develop subclinical SA/C vasculitis and SA/C-LMP, but not NA. The earliest death (day 10) had both CA SA/C vasculitis and SA/C-LMP, and an "eosinophilic-type" myocarditis. CONCLUSIONS/SIGNIFICANCE: NA is the only self-limiting process of the three, is responsible for the earliest morbidity/mortality, and is consistent with acute viral infection. SA/C vasculitis can begin as early as NA, but can occur/persist for months to years; LMP causes progressive arterial stenosis and thrombosis and is composed of unique SMC-derived pathologic myofibroblasts.

Chemotherapy-related leiomyopathy: a suggested morphological explanation for the intestinal dysmotility affecting patients treated with anthracyclines.

Anthracycline, used in oncological chemotherapy, has one well-known side effect: cardiotoxicity. Another is abnormal intestinal motility such as constipation and ileus, the pathogenesis of which, to our knowledge, has not been morphologically investigated. We conducted a study in search of morphological evidence that might shed some light on the pathogenesis of the motility dysfunction. Autopsies performed between 2002 and 2007 were reviewed to select cases of children who had received anthracycline therapy for various neoplasms. The seven patients found had leukemias, lymphomas, or renal solid tumors. They all suffered from constipation or intestinal dysmotility, and no case of anthracyclin-treated neoplasia without the side effect was found in the files. Tissue samples from the heart, gastrointestinal tract, uterus, urinary bladder, and skeletal muscles were examined by light and electron microscopy. As described by others, the myocardium of all anthracycline-treated patients showed loss of myofilaments, fibrosis, mitochondrial proliferation, and pools of accumulated Z-band material. In the gastrointestinal tract and other smooth muscle-endowed organs such as muscular blood vessels, bladder and uterus, the muscularis displayed hyalinization and disorganization, including loss of myofilaments and moderate-severe fibrosis. This study illustrates changes in the smooth muscle, and that of the gastrointestinal tracts and their vessels in particular, in patients treated with anthracycline, who had experienced motility dysfunction associated with their chemotherapy, suggesting that, in addition to the heart, anthracycline may also damage smooth muscle fibers and thus be instrumental in the pathogenesis of the side effects.

Appendiceal goblet cell metaplasia and benign obstructive mucus retention in children: report of eight cases and review of the literature.

We report the clinical-pathologic study of 8 cases of pediatric benign, postobstructive, appendiceal mucus retention in patients 3-15 years of age. The appendices showed very limited acute inflammation. Their most significant change consisted of minimal to mild dilatation of the distal lumen, which was filled with mucus and lined by an epithelium showing often dramatic increase in mucus cells devoid of atypia and without any of the villous proliferation reported in instances of "mucosal hyperplasia" observed in adult patients. In all 8 cases, there was seepage of mucus through the appendiceal wall into the surrounding tissue, eliciting a macrophagic reaction. Proximal to the zones of mucus retention, the lumen of 2 of the appendices was obstructed by a fecalith, and 2 exhibited fibrous obliteration of the lumen at that site. We believe the condition results from obstruction and focal inflammation, which isolate the distal portion of the appendix and elicit goblet cell metaplasia, the secretion of which is followed by luminal distention, eventual rupture, and seepage of mucus within the wall and the mesoappendix. The clinical and radiologic picture of this condition may be mistaken for that of an acute appendicitis complicated by rupture and abscess formation. The report provides an opportunity to describe and characterize "appendiceal mucosal goblet cell metaplasia," a seldom mentioned entity associated with benign appendiceal obstructive mucus retention in children.

Microtubule-severing ATPase spastin in glioblastoma: increased expression in human glioblastoma cell lines and inverse roles in cell motility and proliferation.

We studied the expression and distribution of the microtubule-severing enzyme spastin in 3 human glioblastoma cell lines (U87MG, U138MG, and T98G) and in clinical tissue samples representative of all grades of diffuse astrocytic gliomas (n = 45). In adult human brains, spastin was distributed predominantly in neuronsand neuropil puncta and, to a lesser extent, in glia. Compared with normal mature brain tissues, spastin expression and cellular distribution were increased in neoplastic glial phenotypes, especiallyin glioblastoma (p < 0.05 vs low-grade diffuse astrocytomas). Overlapping punctate and diffuse patterns of localization wereidentified in tumor cells in tissues and in interphase and mitotic cells ofglioblastoma cell lines. There was enrichment of spastin in the leading edges of cells in T98G glioblastoma cell cultures and in neoplastic cell populations in tumor specimens. Real-time polymerase chain reaction and immunoblotting experiments revealed greater levels of spastin messenger RNA and protein expression in theglioblastoma cell lines versus normal human astrocytes. Functional experiments indicated that spastin depletion resulted in reduced cell motility and higher cell proliferation of T98G cells. Toour knowledge, this is the first report of spastin involvement incellmotility. Collectively, our results indicate that spastinexpression in glioblastomas might be linked to tumor cell motility, migration, and invasion.

Multiple intestinal atresias associated with angiodysplasia in a newborn.

This is a report describing the association of multiple small bowel atresias with multifocal angiodysplasia of the intestinal wall in a newborn. To the authors' knowledge, such association has never been reported.

Renal giant cytoplasmic inclusions in Chédiak-Higashi syndrome: first ultrastructural demonstration in a human biopsy.

This report ultrastructurally illustrates the giant lysosome-related organelles in the various cellular components of a renal biopsy from a 10 year-old female affected by the Chédiak-Higashi syndrome. Albeit similar observations have been made and reported in animal models of the syndrome, to the author's knowledge, this is the first illustration of the changes as demonstrated in a human renal biopsy.

FOXO1-FGFR1 fusion and amplification in a solid variant of alveolar rhabdomyosarcoma.

Rhabdomyosarcoma is the most common pediatric soft tissue malignancy. Two major subtypes, alveolar rhabdomyosarcoma and embryonal rhabdomyosarcoma, constitute 20 and 60% of all cases, respectively. Approximately 80% of alveolar rhabdomyosarcoma carry two signature chromosomal translocations, t(2;13)(q35;q14) resulting in PAX3-FOXO1 fusion, and t(1;13)(p36;q14) resulting in PAX7-FOXO1 fusion. Whether the remaining cases are truly negative for gene fusion has been questioned. We are reporting the case of a 9-month-old girl with a metastatic neck mass diagnosed histologically as solid variant alveolar rhabdomyosarcoma. Chromosome analysis showed a t(8;13;9)(p11.2;q14;9q32) three-way translocation as the sole clonal aberration. Fluorescent in situ hybridization (FISH) demonstrated a rearrangement at the FOXO1 locus and an amplification of its centromeric region. Single-nucleotide polymorphism-based microarray analysis illustrated a co-amplification of the FOXO1 gene at 13q14 and the FGFR1 gene at 8p12p11.2, suggesting formation and amplification of a chimerical FOXO1-FGFR1 gene. This is the first report to identify a novel fusion partner FGFR1 for the known anchor gene FOXO1 in alveolar rhabdomyosarcoma.

Undifferentiated embryonal sarcoma of the liver is associated with mesenchymal hamartoma and multiple chromosomal abnormalities: a review of eleven cases.

Undifferentiated embryonal sarcoma (UES) of the liver is a primitive mesenchymal, malignant neoplasm occurring in children. The link between UES and mesenchymal hamartoma (MH) is controversial. Whether they share the same histiogenesis, representing 2 ends of a spectrum, or are distinct entities is unclear. The genetic aberrations of these neoplasms are not well understood, although a common breakpoint (19q13.4) was recently identified. The purpose of this study was to elucidate immunohistochemical markers that may establish a link between the 2 tumors by reviewing cases of UES and MH. Cases of UES from 1990 to 2008 were identified. Clinical demographics were reviewed. Hematoxylin and eosin staining and immunohistochemical staining for vimentin, alpha-1 antitrypsin, and alpha-fetoprotein were performed. Eleven children were diagnosed with UES. Five cases were seen arising in association with MH, and transitional zones were evident. The mean age at presentation was 10 years. To our knowledge, the 11-month-old patient is the youngest reported case of UES in concurrence with MH. All UES tumor cells were positive for vimentin, diastase-resistant periodic acid-Schiff stain, and alpha-1 antitrypsin. Chromosomal analysis of 3 UES cases, 2 arising with MH, showed complex karyotypes with no involvement of 19q13.4. We suggest a continuum between UES and MH. Although a chromosomal anomaly of 19q13.4 was not identified, a submicroscopic involvement of this locus cannot be excluded. Additionally, our analyses suggest that multiple chromosomal aberrations may be associated with the MH/UES spectrum.

The galactocele of male infants: an intriguing entity. Study and reflection about a case, with review of the literature.

In this report, the authors investigate and discuss a galactocele that developed in the breast of a 5-month-old male. Based on the histological and immunohistochemical findings, they suggest that the rare and intriguing process that is exclusively observed in males in the absence of any detectable hormonal stimulation at time of investigation could represent a developmental anomaly possibly promoted by an obstructive phenomenon involving a defect of hollowing of some primary epidermal buds, the precursors of the mammary ducts.

The vascular groove sign: a new CT finding associated with osteoid osteomas.

OBJECTIVE: We have observed that osteoid osteomas are frequently surrounded by thin curvilinear or serpiginous low-density grooves in the surrounding bone on CT examinations. We believe that these grooves represent prominent enlarged feeding arterioles, corresponding to recently published histologic findings. This study was performed to assess the sensitivity and specificity of this vascular groove sign for differentiating osteoid osteomas from other radiolucent bone lesions. MATERIALS AND METHODS: The study group consisted of 42 patients with pathologically proven osteoid osteomas. The control group included 29 patients with radiolucent bone lesions other than osteoid osteomas. Two readers scored CT examinations of these lesions for the presence of the vascular groove sign, defined as one or more radiolucent linear or serpiginous grooves extending from the periosteal surface of bone down to the radiolucent tumor. Sensitivity and specificity values were calculated for each reader. Positive and negative predictive values, p values, and interobserver agreement values were calculated. RESULTS: The sensitivity of the vascular groove sign for detection of osteoid osteoma was 73.8% for reader 1 and 76.2% for reader 2, specificity was 96.6% for reader 1 and 89.7% for reader 2, positive predictive value was 96.9% for reader 1 and 91.4% for reader 2, and negative predictive value was 71.8% for reader 1 and 72.2% for reader 2. The p value was less than 0.0001 for both readers. The interobserver agreement was very good, with a kappa value of 0.85. CONCLUSION: The vascular groove sign is a moderately sensitive but highly specific sign for distinguishing osteoid osteomas from other radiolucent bone tumors on CT.

Differential expression and cellular distribution of gamma-tubulin and betaIII-tubulin in medulloblastomas and human medulloblastoma cell lines.

In previous studies, we have shown overexpression and ectopic subcellular distribution of gamma-tubulin and betaIII-tubulin in human glioblastomas and glioblastoma cell lines (Katsetos et al., 2006, J Neuropathol Exp Neurol 65:455-467; Katsetos et al., 2007, Neurochem Res 32:1387-1398). Here we determined the expression of gamma-tubulin in surgically excised medulloblastomas (n = 20) and in the human medulloblastoma cell lines D283 Med and DAOY. In clinical tissue samples, the immunohistochemical distribution of gamma-tubulin labeling was pervasive and inversely related to neuritogenesis. Overexpression of gamma-tubulin was widespread in poorly differentiated, proliferating tumor cells but was significantly diminished in quiescent differentiating tumor cells undergoing neuritogenesis, highlighted by betaIII-tubulin immunolabeling. By quantitative real-time PCR, gamma-tubulin transcripts for TUBG1, TUBG2, and TUBB3 genes were detected in both cell lines but expression was less prominent when compared with the human glioblastoma cell lines. Immunoblotting revealed comparable amounts of gamma-tubulin and betaIII-tubulin in different phases of cell cycle; however, a larger amount of gamma-tubulin was detected in D283 Med when compared with DAOY cells. Interphase D283 Med cells exhibited predominantly diffuse cytoplasmic gamma-tubulin localization, in addition to the expected centrosome-associated distribution. Robust betaIII-tubulin immunoreactivity was detected in mitotic spindles of DAOY cells. Our data indicate that overexpression of gamma-tubulin may be linked to phenotypic dedifferentiation (anaplasia) and tumor progression in medulloblastomas and may potentially serve as a promising tumor marker.

An adolescent with a mediastinal mass, diagnosed with Graves disease and thymic hyperplasia.

Graves disease is an autoimmune disorder characterized by thyroid enlargement and hyperthyroidism. Thyrotropin receptor (TSHR) autoantibodies bind the TSHR on the membrane of thyroid follicular cells and stimulate cell proliferation and thyroid-hormone synthesis. TSHR has also been identified in extrathyroidal organs, including the human thymus. Thus far, radiologically detectable thymic enlargement has only been reported in adults with Graves disease. We present here the case of a child with Graves disease and significant thymic hyperplasia. L. K. was a 15-year-old girl evaluated for cough and dyspnea on exertion. A chest radiograph was obtained, and it revealed a widened superior mediastinum. A computed-tomography scan of her chest identified a mass in the anterior mediastinum without associated lymphadenopathy. Because of these radiologic findings and her weight loss, she was referred to the oncology service; a biopsy of the mediastinal mass was obtained and revealed thymic reactive hyperplasia. Because of persistent tachycardia, thyroid studies were obtained, and the diagnosis of Graves disease was established. The child's physical examination revealed a minimally enlarged thyroid gland and no exophthalmos. One month after medical treatment was initiated, a repeat computed-tomography scan of her chest identified significantly reduced thymic size. To our knowledge, this is the first pediatric patient reported with Graves disease and significant thymic enlargement. Considering the diagnosis of Graves disease for a child with an anterior mediastinal mass and without the typical physical findings of autoimmune hyperthyroidism (goiter, exophthalmos) may prevent unnecessary diagnostic studies and their associated financial and emotional costs.

Hyperdiploidy with trisomy 9 and deletion of the CDKN2A locus in T-cell acute lymphoblastic leukemia.

We describe the rare finding of a T-cell acute lymphoblastic leukemia (T-ALL) and a pretreatment bone marrow karyotype mosaic for four distinct cell lines in a 4-year-old boy. G-banding analysis of metaphase cells identified a hyperdiploid cell line (52 chromosomes) trisomic for chromosomes 6, 9, 11, 13, 19, and 22. Fluorescence in situ hybridization (FISH) analysis demonstrated that these hyperdiploid cells were missing all three copies of the CDKN2A locus (alias p16/Ink4) at 9p21. FISH analysis of interphase nuclei identified two abnormal cell lines: the majority of cells with homozygous deletions of the CDKN2A locus and some with a heterozygous deletion. In addition, a normal signal pattern was identified in a few cells. This case represents a rare case of hyperdiploidy in T-ALL, and characterizes the clonal evolution of the 9p21 deletion leading to the abnormal karyotype.