Superficially Invasive Vulvar Squamous Cell Carcinoma: A 37-Year-Long Experience of a Tertiary Referral Center

Superficially, invasive vulvar squamous cell carcinoma (SISCCA) (FIGO stage IA) is a rare subset of vulvar cancer defined as a single lesion measuring ≤2 cm with a depth of invasion of ≤1.0 mm. This is a retrospective study performed on 48 patients with SISCCA, surgically treated between 1981 and 2018 at the S. Anna Hospital, University of Turin, to evaluate pathological characteristics and prognosis of these tumors. Ten patients (21%) recurred: seven (14%) as SISCCA and three (7%) as deeply invasive carcinoma. One case with perineural invasion and groin node metastasis at recurrence. No patient had groin lymph node metastases at initial diagnosis. Site of SISCCA, type of surgery, status of surgical margins, and histopathological features did not differ between recurrent and non-recurrent patients. We observed a non-significant trend towards an increase of recurrences in younger women (median age: 63 years vs. 70 years, p = 0.09), while, surprisingly, smaller tumors (<12 mm) were significantly related to tumor relapse (p = 0.03). Overall, SISCCA has a good long-term prognosis, regardless of the pathological characteristics and the type of surgical treatment. We recommend close follow-up, especially for younger patients and for small tumors, due to the possibility of recurrence or re-occurrence even after years.