“…27,28 The frequency of regional nodal metastases varies with anatomic site, histologic features such as increasing tumor thickness and histologic dedifferentiation, tumor size, host immune competency, perineural invasion, and prior treatment. 19,[28][29][30][31][32][33][34][35] Squamous cell tumors arising in nonglabrous mucocutaneous sites such as the lip, vulva, penis, and perianal area are also more likely to metastasize than those involving other areas of the skin. 29 Squamous cell carcinoma arising in areas of chronic inflammation, nonhealing wounds, chronic osteomyelitis, and in irradiated fields are known to be particularly aggressive, with rates of nodal metastases between 18% and 30%.…”