system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 44-year-old woman presents for her annual physical checkup. She says she first noticed a mass in her right breast while taking a shower 3 months ago, which has progressively increased in size. She denies any weight loss, fever, night sweats, discharge from or change in her nipples. Her family history is negative for breast, ovarian, and endometrial cancer. She is afebrile, and her vital signs are within normal limits. Physical examination reveals a smooth, multinodular, firm 5 cm x 5 cm mass in the right breast that is mobile and painless. The skin over the mass appears to be stretched and shiny without ulcerations, erythema, or vascular demarcation. On follow-up 6 weeks later, an interval ultrasound of the right breast reveals a well-circumscribed hypoechoic mass with some cystic components that now measures 8 cm x 7 cm. A core needle biopsy of the mass is performed. Which of the following diagnosis is most likely expected to be confirmed by the core needle biopsy in this patient?
assistant
Phyllodes tumor