Q. A 62-year-old white woman comes to her gynecologist’s office for vulvar itching for the past 8 months. She does not have associated vaginal discharge or bleeding. She claims that she has used multiple steroid creams as advised by her physician earlier, but of no use. She is a known hypertensive and is on regular treatment. Her past medical history is significant for carcinoma of the breast which was treated with mastectomy. Her temperature is 98.4°F (36.9°C), pulse is 87/min, blood pressure is 130/80 mmHg, and respirations are 15/min. Physical examination shows a right mastectomy scar. Pelvic examination shows a well-demarcated, eczematoid red plaque with pale islands of tissue on the right side of the vulva. No lymphadenopathy is present. Which of the following is the most probable diagnosis in this patient based on her clinical features?