Immunohistochemical analysis of vascular endothelial growth factor (VEGF) and p53 expression in pterygium from Tunisian patients.

A pterygium is characterized by abnormal fibrovascular corneoconjunctival tissue. A number of investigations have attempted to elucidate this incompletely understood pathology. Since vascular endothelial growth factor (VEGF) and p53 are known to participate in tumor vascularization, our purpose was to study VEGF and p53 expression in active primary and recurrent pterygium from Tunisian patients. To this end, 15 cases of active primary pterygium and five cases of recurrent pterygium from Tunisia were studied by immunohistochemistry. Antibodies raised against VEGF and p53 were used to analyze the distribution and expression of these markers in pterygium and normal human conjunctiva were used as negative control. VEGF and p53 proteins were found in all cases of primary pterygium in epithelial, fibroblast and vascular endothelial cells. Active primary and recurrent pterygium have different patterns of expression. In primary pterygium, an important variability of p53 and VEGF expression was observed. However, in recurrent pterygium, p53 immunoreactivity was weak to moderate, whereas VEGF immunoreactivity was strong. In normal human conjunctiva, VEGF and p53 expression was weak to negative. The overexpression of VEGF in active primary and recurrent pterygium suggests that angiogenesis may play a role in pterygium pathogenesis and the expression of p53 in active primary pterygium, which might be associated with its mutated form, supports the hypothesis that actinic radiation may be involved in the genesis of pterygium. Thus, VEGF and p53 may be useful biomarkers for understanding the physiopathology of pterygium.

[Recurrent primary mediastinal liposarcoma with histological change]. / Liposarcome médiastinal primitif récidivant avec modification histologique.

INTRODUCTION: Primary mediastinal liposarcomas are rare tumours with various histological features. Local recurrence is frequent. CASE REPORT: We report the case of a 70-year-old patient, in whom a mediastinal mass was resected surgically and identified as a mediastinal, "lipoma-like" liposarcoma on histopathological examination. Nine years later, the patient complained of dyspnoea with cough. The chest X-ray showed anterior mediastinal enlargement and the chest CT scan revealed a heterogeneous mass containing both solid tissue and fat. The patient underwent a successful surgical resection of the mass and the histopathological examination confirmed the diagnosis of a recurrent, mixed-type liposarcoma of the mediastinum (well-differentiated and myxoid). CONCLUSION: This report discusses the epidemiological, clinical and therapeutic features of this tumour.