Spindle cell carcinoma of the vulva: a series of 4 cases and review of the literature.

Spindle cell or sarcomatoid squamous cell carcinoma is an uncommon variant of squamous cell carcinoma of the vulva (SCCV) with only 12 well-documented cases reported to date. Morphologically tumors may be biphasic or monophasic, and uncommonly include heterologous elements. Only 1 reported vulval tumor has previously been investigated for human papillomavirus DNA content. We describe 4 women with spindle cell (sarcomatoid) SCCV, 3 of which occurred de novo and 1 followed radiotherapy for previous SCCV. The tumors in all 4 women arose in a background of lichen sclerosus, and 3 were associated with vulval intraepithelial neoplasia differentiated (simplex) type. All tumors were negative for human papillomavirus DNA on polymerase chain reaction analysis. One case is the second reported with malignant heterologous elements described in the vulva. These tumors seem to be more aggressive than conventional SCCV.