Why are granulomas called tubercles in tuberculosis?

In the context of pathology, the term tubercle is derived from the Latin word tuberculum, which is a diminutive of tuber, meaning a small, knobby prominence or nodule.1

While a granuloma is a general term for a mass of chronically inflamed tissue—often formed by the accumulation and fusion of activated macrophages to sequester persistent stimuli—the specific lesion characteristic of tuberculosis is historically and clinically referred to as a tubercle. The name reflects the physical appearance of these discrete, small, abnormal lumps that develop within the substance of an organ or skin during the infection caused by Mycobacterium tuberculosis.12