It is important to exclude any coexisting malignancy or atypia present at diagnosis as these occur in 8-15% of cases on presentation, and these justify an en bloc resection with possible radiotherapy, depending on the histology and degree of invasion (Fig. 15.34a, b). It is
important that all macroscopically diseased tissue is examined in order to avoid malignancy being missed (Fig. 15.35 a-d).
The management of lesions without malignancy or atypia is more contentious, as the orthodox view has been that wide excision leads to reduced recurrence rates and a reduced risk of malignant transformation. A review of the world literature shows that, while malignant transformation does occur, it is very unusual (Jones, 1998 b).
The main determinant of the endonasal approach in benign lesions is the extent of disease and whether it
is possible to remove all macroscopic disease. This is one circumstance when the edict that mucosa should be preserved at all costs does not apply, and success is influenced by the ability to remove all the diseased mucosa. It is now recognized that when there is no malignancy it is purely a mucosal disease and that the likelihood of cure depends not only on the removal of all macroscopically diseased tissue but also on host immunity and resistance. It is associated with human papilloma viruses 16 and 11; these probably alter the mucosa's genome and they may also be present in some tissue that has yet to show macroscopic evidence of disease.
The authors have operated on patients with very extensive disease (many previous procedures involving all sinuses bilaterally, and the septum) and, in spite of thorough attempts to remove all diseased tissue, have felt that they had not been successful. However, some of these patients have then been disease free while others have had very limited residual disease reappear, but surprisingly not affecting a number of areas where a reappearance of disease was anticipated. This has led us to believe that there is also an immunological aspect to this disease that affects prognosis. Perhaps a reduction in tumor antigen load in these patients after surgery may help eradicate any residual disease. Smaller lesions may not only be more readily excised but may represent better host immunity.
Recurrence rates are often quoted as being over 30 % and this of course represents residual disease. The most difficult areas for excision are the frontal sinus
(Fig. 15.36a, b), the anterior wall of the maxilla, and the nasolacrimal system.
There are now several series that show similar results from both endoscopic and more radical surgery (WaitzandWigand, 1992;Tufano etal., 1999; Cheeand Sethi, 1999), although others have shown better results with more radical surgery (Mansell and Bates, 2000). Endoscopic surveillance is needed after excision, allowing any recurrence to be excised early in order to limit its spread (Fig. 15.37a, b).The authors have never seen a recurrence when endoscopy has been clear for 3 years and we have 90% who are disease free after a mean of 10 years following endoscopic medial maxil-lectomy (Kraft et al., 2003). There are many reports of disease appearing long after excision, but these come from the pre-endoscopic era. lTVl* 14
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