Microinvasive carcinoma of the vulva.

Thirty cases of microinvasive squamous cell carcinoma of the vulva were seen from 1972 to 1978 inclusive. They comprised 37.7% of 77 cases of squamous carcinoma of the vulva seen during this period of time. The results of analysis of multiple factors, including tumor depth and pattern of invasion, nuclear and histologic grade, volume, inflammatory response, presence of vascular invasion, and depth of invasion as compared to the depth of adjacent skin appendages and rete ridges are presented. Two patients were found to have inguinal lymph node metastasis: in one of these patients the tumor was deeper than the adjacent deepest skin appendages while in the second patient skin appendages were not adjacent to the tumor. These tumors measured 2.25 and 1.8 mm in depth, respectively. In both patients the tumor was of high nuclear grade and had a diffuse pattern of infiltration. No nodal metastases were found in patients whose tumors did not invade deeper than 1.5 mm or deeper than the adjacent deepest skin appendage. Tumors measuring 1.5 mm in depth had tumor volumes under 1,000 mm3. The only death from tumor that occurred in this series occurred in a woman who had a second primary tumor of the vulva following a local excision for her microinvasive carcinoma. The definition and measurements of microinvasive carcinoma of the vulva are discussed and an improved method of measurement is proposed.