So far, five cases of regional lymph node recurrences following treatment for FIGO stage Ia squamous cell carcinoma of the vulva have been reported in the literature [4–8]. One of two cases described by Thangavelu et al  cannot be considered true stage IA disease as the tumor was multifocal at initial presentation, the official FIGO classification stating that "Stage IA carcinoma of the vulva is defined as a single lesion measuring 2 cm or less in diameter with a depth of invasion of 1.0 mm or less..." .
Age at initial diagnosis was between 39 and 84 years. Tumors were well differentiated (G1) in three patients [4, 7, 8] including the present case. None of the tumors showed lymphvascular space involvement. In four patients, vulvar intraepithelial neoplasia (VIN) was also present [4–6]. All patients with the exception of the case presented here had had a long-standing history of local complaints such as pruritus or suffered from vulvar diseases such as lichen sclerosus prior to the diagnosis of vulvar cancer.
The case reported by Volgger et al  is unusual as the patient had received immunosuppressive treatment for twelve years following a renal transplant. Long-standing Immunosuppression may have influenced the course of disease leading to groin node recurrence which occurred only four months after initial diagnosis, whereas, in the other five cases of microinvasive carcinoma, recurrence free survival was reported between 12 and 36 months.
All inguinal recurrences were unilateral. Five patients [4–6] including the present case died from progressive disease and/or distant metastases. In the other two cases [7, 8], no follow-up information was provided.
In summary, no pattern of particular risk factors can be deducted from this small number of cases. Theoretically, HPV status of the tumor tissue may play a role. However, Pinto et al  did not find an association between HPV DNA in the primary tumor and clinical outome in patients with vulvar carcinoma, whereas viral presence in the inguinal lymph node metastases was indeed associated with a worse prognosis.
As the salvage rate for patients with inguinal recurrence is low, the development of groin metastases might have been avoided in some of these patients if inguinal lymphadenectomy had been performed at the time of initial cancer diagnosis . In retrospect, the patient discussed in this article had been brought into remission through secondary lymph node dissection and radiation therapy. At the time of recurrence she was already 82 years old. In a younger patient, radiation therapy with the concurrent administration of cytotoxic treatment using cisplatin should have been considered.
A more extensive surgical approach including pelvic lymphadenectomy should be reserved for the debulking of grossly positive nodes. In all other cases the routine removal of pelvic lymph nodes is obsolete .
In conclusion, the definition of microinvasive carcinoma of the vulva based on depth of invasion alone is not as reliable as previously thought for ruling out inguinal lymph node involvement or recurrence. Although the present standard of care cannot be revised on the basis of a very small number of cases, the necessity of inguinal surgery for microinvasive carcinoma needs to be discussed on an individual basis taking into account the age of the patient as well as the potential morbidity. In addition, immunocompromised patients may be at a significantly higher risk for inguinal spread of vulvar cancer.
Thus, unilateral inguinal lymph node dissection through a separate incision should not be ruled out entirely in patients with microinvasive vulvar cancer. Certainly, radical groin node dissection with removal of the fascia lata and resection of the saphenous vein is not justified. Instead, the surgical procedure should be tailored to the exact localization of inguinal lymph nodes as defined by several anatomical studies [13–15].
Nevertheless, lymph node involvement is rare if depth of invasion is less than one millimeter, and omission of inguinal lymph node dissection may be discussed individually with selected patients in order to avoid the considerable morbidity following inguinal surgery. In the future, these patients should undergo sentinel lymph node biopsy. Although not yet applied routinely in vulvar cancer patients, preliminary studies show its feasibility: Sliutz et al  have been able to identify one or more sentinel lymph nodes in all 26 patients studied. Furthermore, the survival of patients with early vulvar cancer treated with sentinel lymph node biopsy and radical local excision appears to be excellent .