Ovoid glands with scant but detectable spindled stroma lie beneath the squamous epithelium.
Vulvar endometriosis is rather rare. It generally occurs after an episiotomy or other trauma, when endometrial tissue implants into the wound. It appears as bluish, red firm cyst or nodule that enlarges with menses.1
1 Mills SE, ed. Sternberg's Diagnostic Surgical Pathology.4th Ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2004: 2336.
2 Kurman RJ, Norris HJ, Wilkinson E. Tumors of the Cervix, Vagina and Vulva: Atlas of Tumor Pathology. Third Series Fascicle 4. Washington DC; AFIP: 1990: Section 7.7.2.