ABSTRACT
The parotid gland is the most common site for the uncommon salivary glands tumors. However the immunohistochemical characteristics of the salivary gland tumors, regarding expression of proliferating cell antigens and oncogenes, in relation to their clinical behavior have not been fully clarified. These may provide predictive quantitative measures for the prognosis of salivary neoplasms and may assess in their management. The aim of this study was to detect the immunohistochemical expression of epidermal growth factor receptor [EGFr], ki-67 proliferating cell antigen and p53 concoprotein in major salivary glands tumors and also to study the relation between these markers expression and the clinicopathological parameters of these tumors focusing on prognostic factors and tumor differentiation. Thus twelve patients with primary tumors of their major salivary glands were included in this study. They were seven men and five women and ranged in age between 32 to 67 years [mean age=51.7 years]. All patients were treated surgically by complete excision of their masses after preoperative investigations including computed tomographic [CT] scan and fine-needle aspiration biopsy [FNAB] and followed up clinically postoperatively for a period ranging from 11 to 48 months [average =33 months]. The tumor size ranged between 15 and 55 mm [average = 31.2 mm]. The clinicopathologic features and the immunohistochemical expression of EGFr, p53 and ki-67 detected with monoclonal antibodies in these cases were analyzed. The results revealed that 6 cases [50%] showed grade-1 of differentiation while the other 3 cases [75%] were grade-II. None of these cases had cellular pleomorphism, vascular or neural invasion, recurrence, lymph modes or distant metastasis. [5 cut of 6 cases. 83.3%] and in all ALs and MECs with no significant differential expression in the various salivary gland tumors. However, p53 and ki-67 expressions were negative in almost all benign cases [PAs and Als] and positive in all MECs but with no significant difference between grade-1 and grade-II cases. Also, no significant association was found between any of these cell markers and the evaluated clinicopathologic parameters of these tumors regarding tumor location, size, aggressiveness, recurrences, lymh nodes or distant metastasis. In conclusions, there was a high prevalence of EGFr expression in primary salivary glands tumors [either benign or malignant with no significant difference]. However, p53 seems to be involved in the pathogenesis of MECs but not in Pas or Als. Also, the highly significant difference in expression of p53 and ki-67 biomarkers between the benign and the low-grade malignant tumors of the major salivary glands can help to distinguish between them, although they may have similarities in their clinicopatholoogic features