Biological Behavior Of Lesions Research Articles

Immunoexpression of proliferation and apoptosis markers in oral vascular anomalies.

The biological behavior of lesions is highly dependent on the imbalance between their proliferative and apoptotic capacity. This study evaluated a correlation between the proliferative and apoptotic rates of different oral vascular anomalies (VAs) by analyzing the immunoexpression of proliferation (Ki-67) and apoptosis (Bcl-2 and Bax) markers in endothelial cells of 20 cases of GLUT-1 positive infantile hemangiomas (IHs), 20 cases of pyogenic granulomas (PGs) and 20 cases of vascular malformations (VMs). Immunoexpression analysis of Ki-67, Bcl-2 and Bax revealed a lower median percentage of positive cells in VMs cases compared to IHs and PGs cases (P <0.001). The Wilcoxon signed-rank test showed significantly higher percentages of immunostaining for Bax than for Bcl-2 in IHs (P = 0.048). In the group of PGs, a positive correlation was observed between the immunoexpressions of Ki-67 and Bax (r = 0.476; P = 0.034). Although oral IHs, PGs and VMs present similar clinical and histopathological features, each of these lesions has its etiopathogenic particularities. The results of this study suggest that different biological behaviors of VAs may be related to differences in the proliferative and apoptotic profiles of their endothelial cells.

Collagen and Its Role in predicting the Biological Behavior of Odontogenic Lesions.

Odontogenic cysts and tumors have variable recurrence rates. Recurrence rate is mainly due to the activity of the epithelium. The epithelium of these lesions has been investigated extensively in regard to their role in proliferative and aggressive behavior of the lesions. However, the role of the connective tissue wall in their behavior has not been studied as extensively. Collagen is an essential part of the connective tissue as a whole and fibrous wall of cystic lesions especially. It is demonstrated by picrosirius red dye staining combined with polarization microscopy. This method permits the evaluation of the nature of the collagen fibers in addition to their thickness. A total of 56 histopathologically diagnosed cases comprising odontogenic follicle, dentigerous cyst, unicystic ameloblastoma, keratocystic odontogenic tumor (KCOT), multicystic/solid ameloblastoma, and ameloblastic carcinoma were taken and stained using picrosirius red stain and evaluated using a polarizing microscope. Collagen fibers in odontogenic follicles and dentiger-ous cysts showed predominant orange-red birefringence; fibers in unicystic ameloblastoma and KCOT showed both orange red and greenish-yellow birefringence; and fibers of multicystic/ solid ameloblastoma showed predominant greenish-yellow birefringence and ameloblastic carcinoma that showed almost complete greenish birefringence. As the biological behavior of the lesions in the spectrum studied progress toward aggressive nature, increase in immature collagen fibers is noticed. This study suggests that the nature of collagen fibers plays a pivotal role in predicting the biological behavior of odontogenic lesions. Aggressive nature of the odontogenic lesions is determined by both the epithelium and the connective tissue components (collagen). Studying the nature and type of collagen helps in predicting its biological behavior.

Glucose Transporter 1 Expression in Odontogenic Keratocyst, Dentigerous Cyst, and Ameloblastoma: An Immunohistochemical Study.

An array of odontogenic lesions manifest in the maxillofacial region with variable presentations. The biological behavior of lesions, such as odontogenic keratocyst (OKC), dentigerous cyst (DC), and ameloblastoma (AM) always invite debate. Glucose transporter 1 (GLUT-1) is proven to be an indicator of metabolic behavior of several benign and malignant neoplasms. The purpose of this study was to evaluate the expression of GLUT-1 in OKC, DC, and AM to understand their metabolic behavior. Immunohistochemical expression of GLUT-1 was evaluated in each of the 15 cases of OKC, DC, and AM. The number of labeled cells, staining intensity, and membrane or cytoplasmic expressions were the parameters assessed and analyzed using chi-square test. All cases showed positive GLUT-1 expression: 86.6% OKC showed more than 50% labeled cells followed by DC (40%) and AM (26.5%); 53.3% OKC showed strong intensity in comparison to AM, which showed weak intensity in 53.3% cases; 86.6% of OKCs showed both membrane and cytoplasmic expression followed by DC (40%) and AM (26.6%), whereas 73.3% of AM showed only membrane expression followed by DC (60%) and OKC (13.3%). Odontogenic keratocyst was found out to be more metabolically active followed by DC and AM.

Expressão de MMPs, marcadores angiogênicos e proliferação celular em tumores odontogênicos

INTRODUÇÃO E OBJETIVO: O conhecimento do comportamento biológico de lesões de natureza odontogênica é essencial para tornar a abordagem terapêutica adequada e estabelecer um prognóstico. A produção de metaloproteinases da matriz extracelular (MMPs), a angiogênese e a proliferação celular fornecem subsídios para o crescimento tumoral. O presente artigo tem como objetivo fazer uma revisão de literatura de pesquisas em tumores odontogênicos (TOs) selecionados a partir da nova classificação da Organização Mundial da Saúde (OMS) de 2005 sobre a expressão de MMPs, marcadores angiogênicos e proliferação celular e verificar, nestes estudos, a relação desses marcadores quanto ao comportamento biológico dessas lesões. RESULTADOS: Nota-se que as MMPs -1, -2, -7, -9 e -26 encontram-se mais expressas no componente epitelial e estroma e, particularmente, a -13 em estroma. Uma maior angiogênese é observada em TOs mais agressivos. CD 105 foi mais expresso no TO ceratocístico (TOC) e CD34 em ameloblastomas sólidos (ASs). Relata-se elevada expressão do Ki-67 e p53 no TOC e no AS e baixo índice de proliferação celular no TO adenomatoide (TOA). CONCLUSÃO: Esses resultados mostram que as MMPs participam no processo de invasão e recorrência de algumas lesões odontogênicas, estando associadas ao comportamento biológico desses tumores. A angiogênese é fundamental para fornecer suporte à proliferação celular e esses dois eventos em conjunto estão correlacionados com diferentes níveis de comportamento biológico nos TOs, quando comparados com cistos de natureza odontogênica, o que pode sugerir o uso de inibidores angiogênicos como provável abordagem terapêutica nessas lesões.

Myofibroblasts in stroma of odontogenic cysts and tumors can contribute to variations in the biological behavior of lesions

Stromal myofibroblasts (MF) have the potential to facilitate progression of neoplastic epithelial lesions that could contribute to their biological behavior. To assess immunohistochemically the frequency of stromal MF in different odontogenic cysts and tumors and correlate it to their aggressive biological behavior. The study included cases of dentigerous cyst (DC, n = 7), odontogenic keratocyst-parakeratinized type (OKC-P, n = 8), orthokeratinized type (OKC-O, n = 9), ameloblastic fibroma/fibro-odontoma (AMF/O, n = 11), unicystic ameloblastoma (UAM, n = 6), and solid ameloblastoma (SAM, n = 7). Cases of oral squamous cell carcinoma (SCC, n = 5) served as control. Myofibroblast frequency was assessed as the number of alpha smooth muscle actin (alphaSMA)-positive stromal cells in 10 high-power fields, presented as the mean number of positive cells per field. Counts showed that mean number of positive cells in OKC-P (25.7+/-11.4) was significantly higher than in DC (8.7+/-11.6) (p = 0.024) and in SAM (29+/-7) it was significantly higher than in UAM (14.9+/-4.9) and AMF/O (5.6+/-7.5) (p < 0.001). Counts in OKC-P and SAM were not significantly different from SCC (21.3+/-5.3) (p > 0.05). The high frequency of stromal MF in known aggressive odontogenic lesions, such as OKC-P and SAM, implies that MF can contribute to the biological behavior of these odontogenic lesions. Various pharmacological agents that control stromal MF can be used as an aid to reduce extensive and mutilating surgery in cases of remarkably aggressive odontogenic lesions.

The role of radical gastrectomy with systematic lymphadenectomy for the diagnosis and treatment of primary gastric lymphoma.

We evaluated the therapeutic efficacy of radical gastrectomy for primary B-cell lymphoma of the stomach and attempted to identify patients who could be adequately treated with surgery alone. Several recent gastric lymphoma reports have discussed the therapeutic benefits of various treatment strategies for stage IE and IIE lymphoma. However, few studies have been based on patients accurately staged by systematic lymphadenectomy with subsequent pathologic examination. A retrospective study was performed to evaluate the survival and biologic behavior of lesions in 60 patients with gastric lymphoma who were treated by radical gastrectomy alone. Tumors were classified according to the histopathologic concept of mucosa-associated lymphoid tissue (MALT)-derived lymphoma. A low histopathologic grade was associated with a significantly lower incidence of nodal metastasis (p = 0.07) and less extensive infiltration of the gastric wall (p < 0.005) despite larger tumor size. A 5-year survival rate of >95% was attained with surgery alone for MALT lymphoma and for true stage IE lymphoma diagnosed by pathologic examination of up to N2 lymph nodes routinely performed after radical gastrectomy. Surgery alone is adequate treatment for stage IE or pure MALT lymphoma, provided that the staging is performed after radical gastrectomy.

A correlative nuclear DNA and histologic study of genital squamous lesions in DES exposed progeny.

72 vaginal and cervical squamous lesions from 55 DES-exposed young women were analyzed using the technique of Feulgen microspectrophotometry to correlate the nuclear DNA content with histologic changes and follow-up data. A euploid pattern was observed in 23 specimens (14 cervical and 9 vaginal) histologically classified as immature squamous metaplasia. Of the 49 significant squamous abnormalities, 17 (9 cervical and 8 vaginal) were polyploid, and 32 (26 cervical, 5 vaginal, and 1 pericervical collar) were aneuploid. Most of the lesions with polyploid patterns were histologically classified as atypical metaplasia or slight dysplasia, while most of the aneuploid lesions were moderate and severe dysplasias. Conservative therapy usually eradicates polyploid lesions with no recurrence; in contrast, a high recurrence rate is seen in patients with aneuploid lesions managed with biopsy and/or therapy. The presence of abnormal mitotic figures in aneuploid lesions is the most significant histologic feature which differentiates aneuploids from polyploids. The biologic behavior of lesions can be better appreciated if histologic findings are supplemented with nuclear DNA data.