Antibody targeting of anaplastic lymphoma kinase induces cytotoxicity of human neuroblastoma.

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase aberrantly expressed in neuroblastoma, a devastating pediatric cancer of the sympathetic nervous system. Germline and somatically acquired ALK aberrations induce increased autophosphorylation, constitutive ALK activation and increased downstream signaling. Thus, ALK is a tractable therapeutic target in neuroblastoma, likely to be susceptible to both small-molecule tyrosine kinase inhibitors and therapeutic antibodies-as has been shown for other receptor tyrosine kinases in malignancies such as breast and lung cancer. Small-molecule inhibitors of ALK are currently being studied in the clinic, but common ALK mutations in neuroblastoma appear to show de novo insensitivity, arguing that complementary therapeutic approaches must be developed. We therefore hypothesized that antibody targeting of ALK may be a relevant strategy for the majority of neuroblastoma patients likely to have ALK-positive tumors. We show here that an antagonistic ALK antibody inhibits cell growth and induces in vitro antibody-dependent cellular cytotoxicity of human neuroblastoma-derived cell lines. Cytotoxicity was induced in cell lines harboring either wild type or mutated forms of ALK. Treatment of neuroblastoma cells with the dual Met/ALK inhibitor crizotinib sensitized cells to antibody-induced growth inhibition by promoting cell surface accumulation of ALK and thus increasing the accessibility of antigen for antibody binding. These data support the concept of ALK-targeted immunotherapy as a highly promising therapeutic strategy for neuroblastomas with mutated or wild-type ALK.

Global gene expression profiling of PAX-FKHR fusion-positive alveolar and PAX-FKHR fusion-negative embryonal rhabdomyosarcomas.

Paediatric rhabdomyosarcomas (RMS) are classified into two major subtypes based on histological appearance, embryonal (ERMS) and alveolar (ARMS), but this clinically critical distinction is often difficult on morphological grounds alone. ARMS, the more aggressive subtype, is associated in most cases with unique recurrent translocations fusing the PAX3 or PAX7 transcription factor genes to FKHR. In contrast, ERMS lacks unique genetic alterations. To identify novel diagnostic markers and potential therapeutic targets, we analysed the global gene expression profiles of these two RMS subtypes in 23 ARMS (16 PAX3-FKHR, 7 PAX7-FKHR) and 15 ERMS (all PAX-FKHR-negative) using Affymetrix HG-U133A oligonucleotide arrays. A statistically stringent supervised comparison of the ARMS and ERMS expression profiles revealed 121 genes that were significantly differentially expressed, of which 112 were higher in ARMS, including genes of interest as potential diagnostic markers or therapeutic targets, such as CNR1, PIPOX (sarcosine oxidase), and TFAPbeta. Interestingly, many known or putative downstream targets of PAX3-FKHR were highly overexpressed in ARMS relative to ERMS, including CNR1, DCX, ABAT, ASS, JAKMIP2, DKFZp762M127, and NRCAM. We validated the highly differential expression of five genes, including CNR1, DKFZp762M127, DCX, PIPOX, and FOXF1 in ARMS relative to ERMS by quantitative RT-PCR on an independent set of samples. Finally, we developed a ten-gene microarray-based predictor that distinguished ARMS from ERMS with approximately 95% accuracy both in our data by cross-validation and in an independent validation using a published dataset of 26 samples. The gene expression signature of ARMS provides a source of potential diagnostic markers, therapeutic targets, and PAX-FKHR downstream genes, and can be used to reliably distinguish these sarcomas from ERMS.

Isolated endobronchial atypical mycobacterium in a child: a case report and review of the literature.

Isolated endobronchial lesions caused by Mycobacterium avium are rare, especially in the pediatric population. We share the case of a 10-month-old boy who, after 1 week of cough and low-grade fever, had a radiographic examination showing endobronchial obstruction. At bronchoscopy, a granuloma of the left bronchus intermedius was found. Histopathologic examination revealed necrotizing granulomatous inflammation. Kinyoun Acid Fast stain revealed acid fast bacilli. Cultures were positive for M. avium. Current treatment options and controversies are presented. The roles of antibiotics and steroids in preventing progressive disease are discussed. The need for serial bronchoscopy and the potential benefits of surgical resection are discussed. Isolated endobronchial M. avium infection remains a rare and challenging problem. The paucity of clinical experience, and variation in patient presentation, obligates a high index of suspicion, and frequent follow-up with bronchoscopic examination and pulmonary assessment, for the child diagnosed with isolated endobronchial atypical mycobacterial infection.

Truncus arteriosus and other lethal internal anomalies in Goltz syndrome.

An infant girl of 36 weeks gestational age was found to have cardiovascular and other lethal internal anomalies in addition to characteristic external abnormalities of focal dermal hypoplasia (Goltz syndrome). The internal anomalies included truncus arteriosus type II with truncal origin of hypoplastic pulmonary arteries, cardiac ventricular septal defect, severe hypoplasia of lungs and pulmonary veins, massive diaphragmatic hernia, and absence of the right kidney. Such a combination of severe anomalies has not been reported previously in Goltz syndrome.

Extrarenal nephroblastic proliferation in spinal dysraphism. A report of 4 cases.

Four cases of extrarenal nephrogenic proliferation in the sacrococcygeal region with spinal dysraphism are presented. In two of the cases, features of Wilm's or incipient Wilm's tumor were present. The previous literature on sacrococcygeal nephrogenic tissue is reviewed, and the impact of these findings on the histogenesis of extrarenal sacrococcygeal Wilm's tumor is discussed.

Central neck dissection for the treatment of recurrent thyroglossal duct cysts in childhood.

OBJECTIVE: The recurrence rate of thyroglossal duct cysts removed by the classic Sistrunk procedure exceeds 4%, even in skilled hands. Simple reexcision fails in 33% of these patients. Recent pathology literature suggests that the tracts of thyroglossal duct cysts may arborize, arguing for a wide-field approach to recurrent lesions. We describe the anatomic rationale and technique of an en bloc central neck dissection in children, on the basis of cadaver dissections and histopathologic review of recurrent thyroglossal duct cyst specimens. METHODS: We reviewed the medical records of all the children undergoing surgery for thyroglossal duct cysts and fistulas during the years 1990 to 1998 by the senior author. En bloc central neck dissections were performed on several cadaver specimens to further delineate the anatomic rationale for this procedure. RESULTS: We have performed an en bloc central neck dissection in 7 children, 5 with recurrent or multiply recurrent thyroglossal duct cysts. None has had a recurrence after follow-up of 9 months to 6 years. All have acceptable functional and cosmetic results. CONCLUSION: An en bloc central neck dissection is a logical and effective surgical technique for the removal of recurrent or multiply recurrent thyroglossal duct cysts.

Teratoid Wilms tumor arising as a botryoid growth within a supernumerary ectopic ureteropelvic structure.

We report a case of a teratoid Wilms tumor arising within a supernumerary ectopic ureteropelvic structure in a 7-year-old boy. The tumor was near the right kidney but was completely separate from it. On the contralateral side, the child had a duplication of the ureteral system. Pathologic examination revealed the mass to be completely enveloped by a fibromuscular sac lined by urothelium. The tumor had a botryoid, polypoid architecture and, in addition to areas of classic Wilms tumor, had extensive squamous, mucinous, and columnar elements. Teratoid Wilms tumors are rare and, to the best of our knowledge, have not previously been described as arising either in anomalous urinary structures or at 7 years of age.

Undifferentiated sarcomas of children: pathology and clinical behavior--an Intergroup Rhabdomyosarcoma study.

Undifferentiated soft tissue sarcoma (UND-STS) is the most poorly defined tumor eligible for intergroup Rhabdomyosarcoma Studies (IRS). Recent IRS UND-STS experience was reviewed to assess the histologic characteristics and clinical behavior of undifferentiated sarcomas. Of the 1,527 patients entered on IRS-III and IRS pilot-IV, 96 had tumors classified by the IRS Pathology Committee as UND-STS. Of these, 52 had adequate histologic material for this study. After application of immunohistochemistry, 18 tumors were reclassified, mostly as embryonal rhabdomyosarcomas (RMS), primitive neuroectodermal tumors, and intraabdominal desmoplastic small found cell tumors. The remaining 34 UND-STS had a diffuse hypercellular histologic pattern made up of sheets of medium-sized cells. The tumor cells had a minimal to moderate amount of cytoplasm and a variable nuclear morphology, predominately vesicular with finely granular chromatin. Except for reactivity with antibodies against vimentin, most tumors had a negative immunohistochemical profile. The 5 year Kaplan-Meier survival estimate for patients with non-metastatic disease was 72%, a significant improvement when contrasted with patients diagnosed to have UND-STS in IRS-I and IRS-II.

The pathology of fibrosing colonopathy of cystic fibrosis: a study of 12 cases and review of the literature.

The authors studied eight colectomy and eight biopsy specimens from 12 patients with cystic fibrosis who had developed fibrosing colonopathy, a complication observed in patients receiving high-strength enzyme replacement. The colectomies originated from five male and three female patients ranging in age from 18 months to 6 years. Five individuals had localized strictures of the right colon and three had stenosing fibrosis of the entire colon. The affected colon had a cobblestone appearance, submucosal fibrosis, thickening of the muscularis propria and chronic mucosal inflammation in all patients, with active cryptitis in four. Moderate to severe infiltration by eosinophils, with increase in the number of mast cells, and widespread interruption of the muscularis mucosa were present in every case. Four colectomies were preceded by endoscopic biopsies; four patients who have not undergone surgery also underwent biopsy. All the biopsies showed evidence of active or chronic inflammation, and all had increased mucosal eosinophils. Prolonged colonic mucosal contact with either the enzymes and/or the enteric coating itself may lead to mucosal colonic ulceration and inflammation. Topical allergy may then promote the stenosing fibroplasia.

Mesenteric pleomorphic liposarcoma in an adolescent.

We report a case of pleomorphic liposarcoma arising in the root of the mesentery of an adolescent girl. Pleomorphic liposarcoma is an extremely rare tumor in the pediatric age group, and few well-documented cases are found in the literature. To the best of our knowledge, none have been described in the abdomen. The histologic and ultra-structural features of this tumor are described, and the literature concerning pediatric pleomorphic liposarcoma is reviewed.

Ménétrier disease of childhood: role of cytomegalovirus and transforming growth factor alpha.

OBJECTIVE: Because the role of cytomegalovirus in Ménétrier disease in children remains unclear and recent studies have implicated transforming growth factor alpha in the pathogenesis of this disease in adults, we investigated the possibilities that (1) cytomegalovirus is etiologic in Ménétrier disease in children and (2) transforming growth factor alpha mediates its development. METHODS: The presence of a cytomegaloviral infection and the pattern of transforming growth factor alpha immunolocalization were determined in the gastric mucosa of four pediatric patients with Ménétrier disease, in control subjects (children with normal gastric mucosa, gastritis, or prostaglandin E1-induced antral hyperplasia), and in adults with Ménétrier disease. RESULTS: Evidence of a cytomegaloviral infection was present only in the four children with Ménétrier disease. The pattern of transforming growth factor alpha immunostaining was identical in the specimens from pediatric and adult patients with Ménétrier disease. This pattern was distinct from that found in the pediatric control specimens. CONCLUSIONS: These data strengthen the possibilities that cytomegalovirus is etiologic in children and that transforming growth factor alpha is involved in the pathogenesis of Ménétrier disease in both children and adults.

Sudden death in childhood due to right ventricular dysplasia: report of two cases.

Two cases of sudden death due to arrhythmogenic right ventricular dysplasia (ARVD) occurring in the pediatric age group are described. One of the subjects, at the age of 7 years, is believed to be the youngest child in whom ARVD has been diagnosed at autopsy. The clinical and pathological characteristics of ARVD are discussed.

Pulmonary hypertension and HIV infection: new observations and review of the syndrome.

This report describes the case of a 14-yr-old hemophiliac who died of complications of primary pulmonary hypertension. He was infected with the human immunodeficiency virus. The autopsy disclosed that he also had membranoproliferative glomerulonephritis type III and hepatic cirrhosis, both clinically unsuspected. This is the second report describing the association of membranoproliferative glomerulonephritis type III and primary pulmonary hypertension in an HIV-infected patient and the first to consider cirrhosis as a possible additional element of the syndrome.

Undifferentiated (embryonal) sarcoma arising in conjunction with mesenchymal hamartoma of the liver.

The histogenesis of the undifferentiated (embryonal) sarcoma of the liver has been much debated. Originally, some investigators suggested that the tumor could originate from a mesenchymal hamartoma. Others doubted this hypothesis. The demonstration of alpha-1-antitrypsin in some tumors and of cytokeratins in others gave rise to new theories suggesting that the tumor was either a fibrous histiocytoma or a sarcomatoid hepatocellular carcinoma. As a new development in this search for the genesis of the undifferentiated (embryonal) sarcoma of the liver, this report describes a case that seems to substantiate, for the first time, the original hypothesis histogenetically linking the undifferentiated (embryonal) sarcoma and the mesenchymal hamartoma. The case is that of a 12-yr-old girl who developed an undifferentiated (embryonal) sarcoma of the liver in conjunction with a mesenchymal hamartoma. Furthermore, in places, the tumor exhibited striking epithelial differentiation as well as immunoreactivity for cytokeratins, alpha-1-antitrypsin and vimentin. Immunoreactivity for alpha-fetoprotein was limited to the areas of epithelial differentiation.