HB - Anatomia Patológica
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- A comparison of microsatellite instability in early onset gastric carcinomas from relatively low and high incidence European populations.Publication . Hayden, JD; Cawkwell, L; Dixon, MF; Pardal, F; Murgatroyd, H; Gray, S; Quirke, P; Martin, IGWe have investigated the genetic basis of gastric carcinomas occurring in patients aged under 40 years from a Portuguese population with a relatively high incidence of gastric cancer. We analysed a panel of 12 microsatellite loci in DNA extracted from gastric carcinomas arising in 16 patients aged 24-39 years from Braga, Portugal. Overall, microsatellite instability (MI) in at least 1 locus was detected in 44% (7 of 16) of carcinomas. A single patient demonstrated a mutator phenotype suggestive of the hereditary nonpolyposis colorectal cancer syndrome with instability in 82% of loci. This carcinoma showed loss of expression of the hMLH1 mismatch repair protein. In a previous study, we found no evidence of MI among 10 cases of early onset gastric carcinomas from an English population, which has a relatively low incidence of gastric cancer. Comparing the 2 series, we found that there was a significant difference (p = 0.04) in the prevalence of MI (at least 1 marker affected). This geographical difference in low-level MI may be related to a significantly higher prevalence of background chronic atrophic gastritis (8 of 16 vs. 0 of 8) and Helicobacter pylori infection (15 of 16 vs. 2 of 8) in Portuguese carcinomas compared with English cases. Genetic mechanisms underlying the hereditary non-polyposis colorectal cancer syndrome may play a role in a small number of early onset gastric carcinomas. The difference in prevalence of low-level MI between these relatively high and low incidence European populations requires further investigation.
- Hemangioma intracranianoPublication . Rocha, J; Marques, C; Adams, A; Rodrigues, JA case of intracranial hemangioma in a neonate is described by the authors. The rarity of the condition raised differential diagnosis problems.
- Secretory breast carcinoma--case report and review of the medical literature.Publication . Costa, NM; Rodrigues, H; Pereira, H; Pardal, F; Matos, ESecretory breast carcinoma (SBC) is a rare type of invasive breast cancer. Since little is known about the biology of this rare tumour, it is useful to report every such case, in order to make as much information as possible available in the medical literature. We present the case of an 18-year-old woman with a SBC treated by mastectomy (Madden) and axillary node dissection (stage pT3N1M0) followed by chemotherapy (FEC regimen) and radiotherapy. The patient has meanwhile completed 4 years of follow-up with no evidence of recurrence. The authors review the literature and summarize relevant findings concerning definition, pathology, clinical picture, treatment, and follow-up.
- Mutation analysis of B-RAF gene in human gliomas.Publication . Basto, D; Trovisco, V; Lopes, JM; Martins, A; Pardal, F; Soares, P; Reis, RMThe RAS/RAF/MEK/ERK kinase pathway is pivotal in the transduction of mitogenic stimuli from activated growth factor receptors, which regulates cell proliferation, survival, and differentiation. Up-regulation of this pathway due to RAS mutations is found in approximately 30% of human tumors. Recently, activating mutations of B-RAF were identified in a large proportion of human cancers. Gliomas are the most frequent primary central nervous system tumors and the molecular mechanisms that underlie the development and progression of these tumors are far from being completely understood. The purpose of this study was to clarify the incidence of B-RAF mutations and their possible relation with tumor progression in a series of 82 human gliomas, including 49 astrocytic and 33 oligodendroglial tumors. The analysis of B-RAF hotspot regions, exons 11 and 15, showed presence of B-RAF mutations in only 2 out of 34 (6%) glioblastomas, and absence in the remaining histological types. Both mutations were located in the hotspot residue 600 (V600E) at exon 15, which leads to constitutive B-RAF kinase activity. These data suggest that activating mutations of B-RAF are not a frequent event in gliomas; nevertheless, when present they are associated with high-grade malignant lesions.
- Pitiríase Rubra Pilar em Doente de Raça NegraPublication . Pereira, TM; Duarte, ML; Vieira, AP; Sousa-Basto, A; Pardal, F
- Primary cutaneous leiomyosarcoma of the facePublication . Pereira, TM; Brito, c; Sousa-Basto, A; Pardal, F
- De encefalopatia e orelhas duras ao síndrome de Sheehan: caso clínicoPublication . Machado, A; Ferreira, C; Lopes, M; Pereira, T; Pardal, F
- Association between functional EGF+61 polymorphism and glioma riskPublication . Costa, BM; Ferreira, P; Costa, S; Canedo, P; Oliveira, P; Silva, AI; Pardal, F; Suriano, G; Machado, JC; Lopes, JM; Reis, RMPURPOSE: Epidermal growth factor (EGF) plays a critical role in cancer. A polymorphism in the EGF gene (EGF+61) may influence its expression and contribute to cancer predisposition and aggressiveness. In the present study, we aimed to elucidate the role of EGF+61 in glioma susceptibility and prognosis. EXPERIMENTAL DESIGN: A case-control study involving 197 glioma patients and 570 controls was done. Univariate and multivariate logistic regression analyses were used to calculate odds ratio (OR) and 95% confidence intervals (95% CI). False-positive report probability was also assessed. The luciferase reporter gene assay was used to ascertain the functional consequences of this polymorphism. RESULTS: Corroborating the univariate analysis, the multivariate model showed that the G allele conferred higher risks for gliomas (OR, 1.32; 95% CI, 1.04-1.67), glioblastomas (OR, 1.47; 95% CI, 1.02-2.10), and oligodendrogliomas (OR, 1.55; 95% CI, 1.07-2.23). The GG genotypes were associated with increased risk for gliomas (OR, 1.71; 95% CI, 1.07-2.73), glioblastomas (OR, 2.03; 95% CI, 1.02-4.05), and oligodendrogliomas (OR, 2.72; 95% CI, 1.18-6.28). In addition, the AG+GG genotypes were associated with higher risk for gliomas (OR, 1.52; 95% CI, 1.03-2.23) and oligodendrogliomas (OR, 2.80; 95% CI, 1.35-5.79). No significant association was observed between the EGF+61 polymorphism and glioblastoma or oligodendroglioma patients' overall survival. The luciferase reporter gene assay exhibited a significant increased promoter activity for the G variant compared with the reference A allele. CONCLUSIONS: These findings support the role of the EGF+61 polymorphism as a susceptibility factor for development of gliomas and show its implication on EGF promoter activity.
- Galectin-3 expression is ubiquitous in tumors of the sellar region, nervous system, and mimics - An immunohistochemical and RT-PCR studyPublication . Rodriguez, FJ; Scheithauer, BW; Roncaroli, F; Silva, AI; Kovacs, K; Brat, DJ; Jin, LGalectin-3 expression has been reported in spindle cell oncocytoma, certain pituitary adenoma subtypes, astrocytomas, oligodendrogliomas, and meningiomas. We evaluated galectin-3 protein expression by immunohistochemistry in 201 cases of a variety of nervous system and sellar tumors, as well as mRNA expression by reverse transcription-polymerase chain reaction in formalin-fixed paraffin-embedded tissue in a subset (20 cases). Immunohistochemical results were evaluated in a semiquantitative fashion on a 4-tiered scale (0 to 3). Strong (3+) immunoreactivity was seen in most of the cases (61%), followed by 2+(22%), and 1+(13%) staining. Only 4% of the lesions studied were immunonegative. Galectin-3 mRNA was present in 15 of the 18 cases (83%) in which reverse transcription-polymerase chain reaction was successful. Significant differences in protein expression were noted in the following 2 settings: specific meningioma subtypes (P=0.004, Fisher exact test) wherein clear cell meningioma demonstrated weak protein expression when compared with other meningioma variants. No significant difference was noted with respect to World Health Organization grade. Galectin-3 was also strongly expressed in benign nerve sheath tumors but only moderately expressed in malignant peripheral nerve sheath tumors (P=0.0009, Fisher exact test). Although galectin-3 positivity is a key feature of the immunophenotype of spindle cell oncocytoma, its consistent expression in other morphologically similar tumors (meningioma, pituicytoma, nerve sheath tumors, granular cell tumor, metastases) makes it of little use in the differential diagnosis of sellar region tumors, a setting in which it should be discouraged. Diagnostic uses of this marker may be limited to specific settings, including some meningioma subtypes and nerve sheath tumors.
- TP53 codon 72 polymorphism in susceptibility, overall survival, and adjuvant therapy response of gliomas.Publication . Lima-Ramos, V; Pacheco-Figueiredo, L; Costa, S; Pardal, F; Silva, A; Amorim, J; Lopes, JM; Reis, RMTP53 is a key tumor suppressor gene that encodes a transcriptional factor involved in several cellular mechanisms, including growth arrest, DNA repair, and induction of apoptosis. In addition to TP53 gene mutations, a common polymorphism, Arg72Pro, has been involved in the carcinogenesis process. The Pro72 variant has been associated with a slower induction of apoptosis and may influence the risk of cancer development. The role of Arg72Pro polymorphism in glioma susceptibility is poorly characterized. With the objective of analyzing the role of the TP53 Arg72Pro polymorphism in glioma risk, overall survival, and patient therapy response in a Portuguese population, we conducted a retrospective case-control study, including 171 patients with gliomas and 526 cancer-free individuals. The Arg72Pro genotype was assessed by the polymerase chain reaction-restriction fragment length polymorphism technique. No statistically significant differences were observed in the genotypic and allelic frequencies between glioma and control groups, and no statistically significant differences were observed with stratification of gliomas into distinct histological subtypes: astrocytic (n = 115), glioblastoma (n = 75), and oligodendroglial (n = 54) tumors. No significant association was observed between TP53 Arg72Pro and patient overall survival, but Kaplan-Meier analysis of glioma patients harboring the Pro72 allele showed a significantly longer survival with adjuvant therapy. In this first assessment of the role of TP53 Arg72Pro polymorphism in a large series of Portuguese glioma tumors, no association was observed with glioma susceptibility or overall survival, except for patients submitted to adjuvant therapy.