A 57-year-old woman has had pain on urination for 5 months and yesterday noted blood on her underwear. On examination, there is a tender red 1-cm nodule on the posterior lip of the external urethra. It is excised. What pathologic finding is most likely to be present on the microscopic examination of her lesion?

She has a urethral caruncle, which is most common in postmenopausal women as a result of urethral prolapse with atrophy from decreased estrogen. Topical estrogen creams and anti-inflammatory agents may shrink the lesion. It is not an infectious process, so multinucleated cells (herpes simplex virus) or plasma cell infiltrates (syphilis) are unlikely. It is not malignant or premalignant. Lichen sclerosus occurs at this age, but not produce a mass lesion.