tubercule

Tubercule is a term used in biology and medicine to denote a small, rounded eminence or nodular projection on a structure. In English, tubercule is a variant spelling of tubercle; tubercule comes from Latin tuberculum meaning a small swelling. The term is used across specialties to describe similar small, knob-like protrusions.

In anatomy, a tubercle is a small, rounded projection on a bone or other hard tissue that serves as a site for muscle or ligament attachment or articulation. Well-known examples include the greater and lesser tubercles of the humerus, where rotator cuff muscles attach, and the tibial tubercle on the tibia.

In medical pathology, tubercle refers to a nodular granulomatous lesion produced by infection with Mycobacterium tuberculosis. The tubercle is composed of immune cells surrounding a central area of caseous necrosis; multiple tubercles may coalesce to form larger lesions, especially in the lungs and lymphatic system. The term is historical but remains descriptive in describing lesion type.

In botany and horticulture, tubercule can describe small wart-like projections on plant surfaces, seeds, or tubers. The usage varies by discipline and is less common in modern nomenclature, but it appears in some botanical descriptions and older texts.

See also tuberculum, tuber, tubercle, and tuberculous disease.