Amplification of the HER-2/neu oncogene is uncommon in pediatric osteosarcomas.

BACKGROUND: Recent reports have described overexpression of p185(c-erbB2), the product of the HER-2/neu oncogene, in more than 40% of archival osteosarcomas that were examined by immunohistochemistry (IHC). However, IHC can be influenced by the method of fixation, extent of antigen retrieval, specificity and sensitivity of the antibody clone, and the use of an arbitrary semiquantitative scoring system. In contrast, fluorescence in situ hybridization (FISH) assays that assess HER-2/neu gene copy numbers in individual cells are more consistent, more reproducible, and less subjective than IHC. METHODS: The authors examined pretreatment nondecalcified archival tissue from 21 high-grade pediatric osteosarcomas for amplification of the HER-2/neu oncogene using an Food and Drug Administration (FDA)-approved FISH assay (PathVysion, Vysis Inc., Downers Grove, IL). Additionally, IHC for p185(c-erbB2) was performed in all cases using the Dako polyclonal antibody clone A0485 (Dako Co., Carpinteria, CA). RESULTS: None of the 21 osteosarcomas had evidence of HER-2/neu gene amplification by FISH, whereas p185(c-erbB2) IHC was negative in all cases. CONCLUSIONS: HER-2/neu gene amplification appeared to be an uncommon event in pediatric osteosarcomas. The reason(s) for discordance between previous IHC data and the current FISH and IHC results was unknown, but might reflect intrinsic variations in antibody clones, or might suggest that, in some cases, the occurrence of protein overexpression is independent of gene amplification.

Aberrant expression of tumor suppressor proteins in the Ewing family of tumors.

BACKGROUND: Deregulation of tumor suppressor gene function and abrogation of cell cycle control are common features of malignant neoplasms, but corresponding data on Ewing sarcomas and primitive neuroectodermal tumors are relatively scarce. We studied the expression of 4 tumor suppressor proteins in the Ewing family of tumors (EFTs). DESIGN: We examined a series of 20 pediatric EFTs for abnormal expression of p16(INK4a), p14(ARF), p21(WAF1), and pRB by immunohistochemical analysis of pretreatment, nondecalcified archival specimens. Clinical follow up was available in all cases (median, 21 months; range, 5-103 months). Five patients presented with metastatic disease, 8 had no evidence of disease at last follow up, and 12 had an adverse outcome (death or progressive tumor posttherapy). RESULTS: Twelve cases (60%) demonstrated abnormal expression of at least one tumor suppressor protein. There were 11 cases (55%) with loss of p21(WAF1) expression, 4 (20%) with down-regulation of p16(INK4a), 2 (10%) with absence of pRB, and one case (5%) with loss of p14(ARF) expression. Loss of p16(INK4a) expression correlated with metastatic disease at presentation (P =.026), and showed a trend toward shortened survival (P =.20). The p21(WAF1), p14(ARF), and pRB status was not significantly correlated with either metastatic disease at presentation or outcome. CONCLUSION: Abrogation of the G1 checkpoint was common in this series of EFTs, and down-regulation of p21(WAF1) and p16(INK4a) were the most frequent findings. Loss of p16(INK4a) expression may identify a subset of cases with a more aggressive phenotype.

Precursor B-cell lymphoblastic lymphoma. A study of nine cases lacking blood and bone marrow involvement and review of the literature.

We describe 9 cases of precursor B-cell lymphoblastic lymphoma (LYL) without evidence of marrow or blood involvement. Four patients had superficial nodal disease, 2 cutaneous involvement, and 1 each ovarian, retroperitoneal, or tonsillar primary tumor. Six patients had limited disease; 3 patients were stage III. Immunophenotyping revealed a terminal deoxynucleotidyl transferase (TdT)-positive, immature B-cell population with variable expression of CD10, CD20, and CD45. All patients are in complete clinical remission (median follow-up, 14 months). A literature review yielded 105 patients with a diagnosis of precursor B-cell LYL based on less than 25% marrow involvement. Of these, 64% were younger than 18 years. Skin, lymph nodes, and bone were the most common sites of disease. Mediastinal involvement was uncommon. TdT, CD19, CD79a, CD10, and HLA-DR were the most frequently expressed antigens, while CD45 and CD20 were expressed in only two thirds of the cases. Cytogenetic analysis showed additional 21q material as a recurring karyotypic abnormality. At a median follow-up of 26 months, 74% of patients were alive; the median survival was 19 months for patients dying of disease. Comparison with precursor B-cell acute lymphoblastic leukemia showed several overlapping features, although distinct differences were identified.

Loss of p16(INK4a) expression correlates with decreased survival in pediatric osteosarcomas.

Abnormalities of the G1 cell-cycle checkpoint are commonly reported in cancers at various anatomic sites. pRB, p16(INK4a) and cyclin D1 are critical G1-checkpoint proteins responsible for maintaining the balance of cellular proliferation. We examined a series of 38 pediatric osteosarcomas for abnormal expression of pRB, p16(INK4a) and cyclin D1 by immunohistochemical analysis of archival biopsy specimens. Overall, 17/38 (45%) osteosarcomas showed evidence of G1-checkpoint abrogation, including 11/38 (29%) with loss of pRB expression and 6/38 (16%) with loss of p16(INK4a) expression. Cyclin D1 over-expression was not detected. There was an inverse correlation between loss of pRB and p16(INK4a) expression (p = 0.07). pRB and p16(INK4a) abnormalities were independent of site of disease, presence of metastasis at diagnosis and percentage of tumor necrosis in the resection specimen. Clinical follow-up was available on all patients (median 31.6 months, range 5.9-116 months). Absence of p16(INK4a) expression significantly correlated with decreased survival in univariate analysis (p = 0.03), while loss of pRB expression did not affect survival. Immunohistochemical analysis of p16(INK4a) expression in pediatric osteosarcomas may be a useful adjunctive marker of prognosis.

Cytomegalovirus and human herpesvirus 6, but not human papillomavirus, are present in neonatal giant cell hepatitis and extrahepatic biliary atresia.

The purpose of our study was to confirm reports of an association of human papillomavirus (HPV) with neonatal giant cell hepatitis (GCH) and biliary atresia (BA), and to expand these studies to include cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus 6 (HHV6), and parvovirus B19 (PVB19). Frozen hepatic tissue was available for polymerase chain reaction (PCR) analysis in 19 cases of GCH or BA and 8 controls. Nested PCR to detect HPV types 6, 16, 18, and 33 was followed by 32P hybridization with generic probes. PCR followed by hybridization with a digoxigenin-labeled probe was used for all other viruses. HPV, EBV, and PVB19 were not detected in cases or controls. Two cases of GCH and 1 case of BA were PCR positive for CMV; controls were negative. HHV6 was detected in 6 cases: 2 GCH, 2 BA, and 2 controls. We conclude that HPV is not associated with GCH or BA. Detection of CMV in BA and GCH confirms other reports of this association. HHV6 requires further study to determine the significance of a positive PCR test in the livers of infants.

Bannayan-Riley-Ruvalcaba syndrome: spectrum of intestinal pathology including juvenile polyps.

Bannayan-Riley-Ruvalcaba syndrome (BRRS) is a disorder that includes juvenile polyposis as part of its pathologic spectrum, and it recently has been shown to share phenotypic and genotypic features with Cowden's disease. In existing literature, descriptions of intestinal pathology in patients with BRRS are relatively sparse and occasionally erroneous. We describe the intestinal pathology in multiple specimens from three children with BRRS. Examination of gastrointestinal biopsies from these children revealed predominantly colonic and rectal polyps with the histology of juvenile polyps. Additionally, two cases with clusters of ectopic ganglion cells within the lamina propria, one in a colonic polyp and one in a duodenal biopsy, and an atypical polyp were observed. Bannayan-Riley-Ruvalcaba syndrome should be included in the list of differential diagnostic considerations when a child or young adult presents with a juvenile polyp, particularly if unusual histologic features such as atypical polyps or ectopic ganglion cells are encountered.

Molecular abnormalities associated with secretory carcinomas of the breast.

Secretory carcinomas (SCAs) represent a unique histological variant of invasive breast carcinomas, occurring predominantly in patients younger than 30 years of age. Data from limited series have shown SCAs to have a favorable prognosis in patients younger than 20 years of age, whereas the clinical course tends to parallel the more common in filtrating ductal carcinomas (IDCs) in patients older than 20 years. There are no reports on the molecular abnormalities associated with this unusual tumor. Microdissected archival formalin-fixed tissue from 10 SCAs collected from 2 institutions were used to determine the frequencies of allelic loss at 13 chromosomal regions with 19 microsatellite markers, using multiplex polymerase chain reaction (PCR)-based techniques. The results of loss of heterozygosity (LOH) and microsatellite alterations (MAs) analyses were compared with 20 cases of IDCs. P53 gene mutation analysis was also performed on the 10 SCAs using single-strand conformation polymorphism (SSCP) analysis, followed by sequencing of abnormal bands. LOH at multiple regions of chromosome 3p were the most common abnormality in both SCAs (55%) and IDCs (50%), followed by LOH at 17q21 (BRCA1 locus), 13q14 (retinoblastoma gene locus), and 8p21-23. No significant differences were seen in the frequencies of LOH at any chromosomal region except for 17p13 (p53 gene locus), where allelic losses were absent in SCAs, but evident in 46% of IDCs (P < .05). The 2 histological entities were similar in the fractional regional loss (FRL) index (0.26 v 0.24), fractional allelic loss (FAL) index (0.23 v 0.27), as well as in the frequency of MAs (0.015 v 0.005), P > .05. P53 gene missense mutation (G:C::A:T) was detected in 1 of 10(10%) SCAs. Based on the considerable similarities in the molecular abnormalities associated with both tumors, the formation of secondary lumina in both the in situ and the invasive components, as well as suggestions from limited series that the clinical behavior in adult patients parallels that of IDCs, SCA most likely reflects a secretory variant of IDCs.

Subcutaneous granuloma annulare: a review of 47 cases.

OBJECTIVE: The purpose of this study was to review and provide information regarding characteristic findings, diagnostic work-up, course, and treatment associated with subcutaneous granuloma annulare (SGA). MATERIALS AND METHODS: The medical and surgical records of 47 patients with SGA, who were diagnosed and treated at our institution over the past 26 years, were reviewed. RESULTS: All patients presented with a painless soft tissue nodule(s) of the extremities or scalp. The mean age at presentation was 4.3 years, with 19% of the patients encountering one or more recurrences. The mean time of recurrence was 10 months. Definitive diagnosis in all patients was made by biopsy, and no patient progressed to any recognized systemic illness or connective tissue disorder. CONCLUSIONS: SGA is a benign inflammatory skin lesion that should be considered in the differential diagnosis of a subcutaneous nodule(s) of the scalp and/or distal extremities of an otherwise healthy child. Because the nodule(s) are benign and may recur with or without surgical biopsy, reassurance is the best management.

Eosinophilic infiltration of the enteric neural plexuses in Hirschsprung's disease.

Inflammatory infiltrations of the enteric plexuses are uncommon and are usually lymphoplasmacytic. Within the past 15 years, nine pediatric cases in which a predominantly eosinophilic infiltrate of the gastrointestinal wall with a predilection for the myenteric (Auerbach's) and deep submucosal (Henle's) plexuses were seen at our institution. Two were neonates without gastrointestinal abnormalities who expired shortly after birth. Seven were patients with short-segment Hirsch-sprung's disease. There was a mild increase in mucosal eosinophils in the overlying mucosa and only one patient had peripheral eosinophilia. Follow-up data obtained 1 month to 7 1/2 years after biopsy revealed no development of inflammatory bowel disease, connective tissue disease, malignancy, allergic disorder, or intestinal dysmotility. The proximal location of the infiltrate suggests that it may represent a secondary finding rather than a primary cause of aganglionosis.

A quantitative evaluation of mucosal eosinophils in the pediatric gastrointestinal tract.

Evaluation of the mucosal eosinophil content is important in the interpretation of endoscopic biopsies, as high eosinophil densities might reflect allergic gastrointestinal disease. Reference ranges gleaned from the literature have an upper limit of normal varying from 6 to 20 eosinophils per 400 x high power field. Preliminary data suggest a geographic variation with higher eosinophil counts in the southern United States. We examined intestinal tract mucosa from 44 infants and children who died suddenly and unexpectedly in northeastern Texas. Subjects ranged in age from 3 wks to 17 yrs and were without known gastrointestinal disease. Using formalin-fixed, hematoxylin and eosin-stained 4-microns sections, intramucosal eosinophils were counted in ten consecutive high power fields and the mean eosinophil count determined. Twenty-three subjects (52%) had counts of > 20 eosinophils/high power field from at least one site. There was no correlation with age, sex, season, or cause of death. In a subset of 11 subjects, more extensive sampling showed the cecum and appendix to have the highest concentration of eosinophils and relatively low counts in the stomach and distal large intestine. These observations correlate with our impression that increased numbers of eosinophils, particularly in the proximal colon, are a common feature of otherwise unremarkable pediatric endoscopic biopsies. Efforts to distinguish the proportion of activated eosinophils in B5-fixed mucosal biopsies using the EG2 monoclonal antibody were unsuccessful, as this antibody does not appear specific for activation in B5-fixed tissue. Mucosal eosinophil counts should be interpreted with caution in geographic areas where a high background count is endemic.

Fetal hypokinesia syndrome in the monochorionic pair of a triplet pregnancy secondary to severe disruptive cerebral injury.

We report a set of triplets, two of whom were monochorionic diamnionic and demonstrated cerebellar hypoplasia and progressive arthrogryposis on an antenatal sonogram. At delivery the infants exhibited a Pena-Shokier phenotype. At autopsy, the twins were concordant for severe disruptive lesions of the cerebrum. The mechanism resulting in the devastating symmetric lesions may have been a transient cerebral vascular compromise associated with placenta vascular anastomoses characteristic of monochorionic twinning. This report accentuates the vulnerability of the monochorionic twin for ischemic cerebral injury.

Thyroid C cells in the DiGeorge anomaly: a quantitative study.

The developmental field defect in the DiGeorge anomaly (DGA) principally affects derivatives of the third and fourth branchial pouches (areas containing a large population of cephalic neural crest cells), including the ultimobranchial body (UB), the reputed source of thyroid calcitonin-producing cells (C cells) in humans. To evaluate the content of C cells in children with DGA, sections of the thyroid in 16 cases of DGA (group I) (8 incomplete and 8 complete forms) and 16 age-matched controls (group II) were stained by immunoperoxidase for calcitonin and chromogranin. Eleven of 16 (69%) cases in group I [4 of 8 (50%) of the complete and 7 of 8 (88%) of of the incomplete cases] and 14 of 16 (88%) of group II exhibited positive-staining cells for both markers, either individually or in small clusters within the follicular epithelial basement membrane. The average number of C cells per high-power field (HPF) (400x) for group I was 1.6 +/- 0.9 and for group II 4.9 +/- 1.7 (P < .005). Although the percentage of positive incomplete DGA cases was the same as that of the control cases, the average number of C cells/HPF was 2.0 +/- 1.1 and similar to that of complete DGA cases (1.2 +/- 0.6). These results demonstrated that C cells are present in the thyroid of patients with DGA more frequently than expected, although in deficient numbers when compared quantitatively to age-matched controls showing a normal infantile pattern of thyroid C cell distribution. Although this observation confirms that there is deficiency of thyroid C cell development in DGA and is in keeping with the assumption that the cells are of neural crest origin, our data raise the possibility of an additional source of C cells, perhaps from thyroid endoderm, in a manner analogous to the endocrine cells of the gut and respiratory tract.

Renal angiomyolipomas and HMB-45 reactivity.

BACKGROUND: Renal angiomyolipomas (RAML) are mesenchymal hamartomas composed of varying amounts of blood vessels, smooth muscle, adipose tissue, and supporting connective tissue. Although most of these tumors are easy to recognize, some show unusual histologic features and may pose a diagnostic dilemma. Recent reports indicate that RAML are immunoreactive for HMB-45 antibody, which is directed against a premelanomasome-associated glycoprotein and is thought to be specific for melanocytic differentiation. METHODS: To determine whether HMB-45 reactivity would differentiate RAML from other renal tumors, the authors immunostained 72 primary renal tumors, including 19 angiomyolipomas and 2 retroperitoneal liposarcomas extending into the kidney, with HMB-45 monoclonal antibody. Also, the immunohistochemical profile of 19 renal angiomyolipomas was investigated using a broad panel of immunostains, including cytokeratin (AE1/AE3), epithelial membrane antigen, vimentin, smooth muscle actin (SMA), desmin, muscle-specific actin (MSA), S-100 protein, and neuron-specific enolase (NSE). RESULTS: All tumors except RAML were negative for HMB-45 antibody. HMB-45 immunoreactivity was present in 17 of 19 RAML. Seventeen of 19 were positive for SMA and MSA (HHF 35), 8 for desmin, 17 for vimentin, and 9 for NSE. CONCLUSIONS: Based on this study, it was concluded that, along with SMA and MSA, HMB-45 reactivity is a useful tool to distinguish RAML, especially those with unusual morphological features, from other primary renal neoplasms, including liposarcomas that extend into the kidney.