Masuda Clinic, located in Iwaimurada, Saku City, Nagano Prefecture, is a medical facility specializing in breast and thyroid diseases. Dr. Hiroyuki Masuda, the director, graduated from Hirosaki University School of Medicine, trained at the Second Department of Surgery, Shinshu University School of Medicine, and earned his medical doctorate. After serving as Chief Surgeon at Saku Municipal Kokuho Asama General Hospital, he opened this clinic in August 2003. He holds numerous qualifications including Japan Breast Cancer Society Breast Specialist and Certified Physician, Japan Thyroid Association Specialist, and Japan Society of Endocrine Surgery Instructor and Specialist, demonstrating exceptional expertise. The clinic is equipped with a mammography device capable of 3D mammography (tomosynthesis) imaging and a high-performance ultrasound diagnostic device with elastography and Doppler functions. The clinic is certified as a Japan Breast Cancer Society Specialist System-Related Facility, Japan Thyroid Association Certified Specialist Facility, and Image-Certified Facility by the Central Committee for Quality Assurance of Mammography Screening. Another feature is the ability to receive explanations while checking thyroid hormone and tumor marker results on the same day as blood collection. If treatment is needed, a referral system to multiple medical institutions including Shinshu University, Saku Medical Center, and Cancer Institute Ariake Hospital is well-established. The clinic has parking and is barrier-free, ensuring easy accessibility.