26th April 2024

A 42-year-old woman presents with a palpable, round, and mobile lump in her left breast that she noticed a week ago

A 42-year-old woman presents with a palpable, round, and mobile lump in her left breast that she noticed a week ago. The lump is tender to touch and located near the outer aspect of the breast. She reports that the lump seems to become more prominent and painful during her menstrual cycle. She has no family history of breast cancer. On examination, the lump is smooth, well-defined, and fluid-filled.

Which is the most likely diagnosis?