Located in Iwamurada, Saku City, Nagano Prefecture, Masuda Clinic is an internal medicine clinic specializing in breast and thyroid diseases. The clinic is staffed by a Japan Surgical Society certified specialist and holds accreditation from the Japan Central Organization on Quality Assurance of Breast Cancer Screening for imaging services. The clinic is equipped with dedicated mammography devices capable of 3D mammography and high-performance ultrasound diagnostic equipment, accommodating patients seeking breast cancer screening or thyroid cancer screening. In addition to this dedicated equipment, the clinic also features thyroid hormone and tumor marker measurement devices, with a system in place to provide explanations while reviewing results on the same day as blood collection. The clinic also offers general blood tests, ECG, blood sugar tests, and urinalysis. Reception hours are until 12:30 PM in the morning and until 5:30 PM in the afternoon. The clinic is closed on Thursday afternoons, Saturday afternoons, Sundays, and holidays. Parking and barrier-free access are available, and medical services are provided in English as well.