This visualization shows the distribution of breast cancer tumor sizes, categorized as Small, Medium, or Large based on the mean area from the dataset. A pie chart displays the count of records in each category, with interactive tooltips revealing exact counts on hover. The chart is rendered as SVG using D3 v7, leveraging `d3.pie`, `d3.arc`, and `d3.scaleOrdinal` for slice geometry, coloring, and a custom legend. Data is loaded from a TSV file via `d3.tsv` and aggregated with `d3.rollup`.