Читать книгу Veterinary Surgical Oncology - Группа авторов - Страница 121

Various anatomical sites for cutaneous MCT have historically been associated with a poor prognosis. These include MCT located in the scrotum, muzzle, and pinnae. Prognosis is correlated more with grade rather than anatomic location and these anatomical locations often have a higher proportion of high‐grade MCTs and more limited wide resection options.

Mast cell tumors are the most common type of cutaneous scrotal tumors diagnosed in dogs (Trappler et al. 2014; Smiech et al. 2018). MCTs located in the inguinal, perineal, or scrotal regions were previously reported to have a poorer prognosis compared to other cutaneous locations (Turrel et al. 1988). More recent studies have refuted this finding and concluded that when MCTs in these locations that are treated appropriately have survival times and tumor‐free intervals equivalent to other cutaneous locations (Cahalane et al. 2004; Sfiligoi et al. 2005). The scrotum, inguinal area, and axilla are however reported to be the anatomical locations with highest incidence of high‐grade MCTs (Reynolds et al. 2019). Scrotal ablation and evaluation of the inguinal lymph nodes are recommended for treatment of scrotal MCTs.

A retrospective study of 24 dogs with MCTs located in the muzzle region identified this location as a site for biologically aggressive tumors with higher regional metastatic rates than previously reported for MCTs in other sites (Gieger et al. 2003). Another study found that dogs with tumors located on the extremities had a longer tumor‐free interval than dogs with MCT located on the trunk (Turrel et al. 1988).

MCTs of the pinnae have also been reported to have a poor prognosis. A prolonged disease‐free interval without local recurrence may be achieved with local excision of grade 1 and 2 MCTs of the pinnae. Animals with grade 3 MCTs of the pinnae, however, are reported to have a poor outcome with short times to local recurrence and median survival time of 10 months (Schwab et al. 2014).