Original Article: PDF OnlyMicroinvasive Squamous Carcinoma of the Vulva: Search for a DefinitionHOFFMAN, JAMES S. MD; KUMAR, NEELAM B. MR; MORLEY, GEORGE W. MDAuthor Information From the University of Michigan Medical Center, Departments of Obstetrics and Gynecology and of Pathology, Ann Arbor, Michigan Obstetrics & Gynecology: May 1983 - Volume 61 - Issue 5 - p 615-618 Free Abstract All cases of stage I squamous cell carcinoma of the vulva from the University of Michigan Tumor Registry from 1935 to 1981 were reviewed. Seventeen of 90 (19%) patients had nodal metastases. All had a depth of invasion of more than 2 mm and all exhibited histologic confluence. The risk of nodal metastases varied with depth of invasion, size of lesion, and histologic grade, although the association with grade was not statistically significant. The size of the lesion influenced the incidence of nodal metastases only in that it was associated with the depth of invasion. Lymphovascular invasion was present in only four patients, but three of them had nodal metastases, including one patient with only 3 mm depth of invasion. © 1983 The American College of Obstetricians and Gynecologists