In a Pinch: An Unusual Case of Zoon's Vaginitis, a Plasma Cell Disorder.

Plasma cell, or Zoon's, vulvitis (PCV) is a rare inflammatory disorder of the female genital tract. Clinically, it is characterized by erythematous mucosal lesions associated with burning, pruritus, and dyspareunia. Histologically, it is characterized by the thinning of the epithelium with the infiltration of plasma cells in the underlying dermis. There are few case reports describing predominantly vaginal symptoms. Our patient is a 53-year-old postmenopausal female presenting for the gynecologic evaluation of a vaginal pinching sensation and vulvar irritation for three months. On examination, vaginal mucosa was notable for erythematous macules and papules with focal tenderness. Initial evaluation was significant for bacterial vaginosis. This was treated, but it did not improve the patient's presenting symptoms. Our preliminary working diagnosis was vulvovaginal atrophy. Biopsies showed plasmacytosis mucosae consistent with Zoon's vaginitis. The patient was treated with external clobetasol ointment and hydrocortisone 25 mg vaginal suppositories with improvement in symptoms. Female genital tract lesions engender a range of differential diagnoses, including infectious, immunologic, and malignant causes. In this patient, our initial working diagnosis of genitourinary syndrome of menopause suggested that local hormonal treatment was indicated. However, histological diagnosis directed the use of steroid treatment, ultimately improving the patient's symptoms.