Search

The aim of this study was to investigate the expression of p16 in relation with the histopathologic features and the clinical course in patients with sinonasal melanoma. Thirty-seven sinonasal melanomas were immunostained for p16. Seventeen tumours were investigated for loss of the 9p21 region using interphase fluorescence in situ hybridization (FISH). Twenty-seven melanomas (72.9%) showed loss of p16 expression. All cases with spindle or mixed cytology showed loss of p16, whereas this was present in 50% of epithelioid tumours (p=0.01). Loss of p16 expression was more frequently seen in melanomas with alveolar architecture (87.5%) than in tumours with diffuse architecture (68.9%) (p=0.4). There was no correlation between p16 expression and presence of lymph node or distant metastases (p=0.57 and 0.24, respectively). In addition, p16 status did not influence overall survival (p=0.2). The FISH results were in good agreement with immunohistochemistry: 11 tumours out of 17 showed deletion of the 9p21 region and 10 of these showed loss of protein expression. Loss of p16 expression is a frequent event in sinonasal melanoma and it is mainly related to deletion of 9p21 region. At variance from cutaneous melanoma, loss of p16 is not correlated with the prognosis of patients affected by sinonasal melanoma.

D2-40 is a monoclonal antibody, which reacts with a fixative-resistant epitope of lymphatic endothelium. Sinonasal-type hemangiopericytoma (SHP) and tumors of the (conventional) hemangiopericytoma/solitary fibrous tumor family (HP/SFT) are characterized by prominent vasculature. However, data concerning D2-40 labeling of these tumors are very sparse. In the present study, we investigated D2-40 staining in tissue specimens of 17 patients with SHP (male to female ratio of 2.4:1, median age of 63 years) and compared the immunolabeling with 20 cases of HP/SFT, including three SFT cases from nasal mucosa. D2-40 was detected in vascular channels of all SHP patients examined. By contrast, all cases of HP/SFT did not reveal any vascular channel being positive for D2-40, neither in the nasal cases nor in the remaining patients. This study presented for the first time data on D2-40 labeling in a series of SHP, HP/SFT, and supports the distinction of SHP from HP/SFT.

We present the clinicopathological, histological and immunohistochemical findings of six cases of primary tubulopapillary low-grade adenocarcinoma of the sinonasal tract with ultrastructural examination in one case. Due to its unique features, we believe that primary tubulopapillary low-grade adenocarcinoma of the sinonasal tract represents a tumour entity different from any tumours generally recognised in the sinonasal region. Our cases had an equal sex incidence, with an age range of 44-76 years. The tumour has a tendency to recur, but none of our six patients developed metastases. We feel that it is important to separate this tumour entity from other types of sinonasal adenocarcinomas that exhibit a papillary growth pattern, as they frequently pursue a much more aggressive clinical course than the tumours in this study.