Acaulous

Definition & Etymology

Acaulous is an adjective describing a structure as sessile, meaning attached directly by its base without a stalk or peduncle. Synonymous with “stemless,” it originates from Greek: a- (“without”) + kaulos (“stalk”). In medicine, particularly pathology, it describes the morphology of lesions like polyps. An acaulous growth adheres broadly to a surface, contrasting with a pedunculated (stalked) growth, a distinction vital for diagnosis.

Clinical Significance

The term’s clinical importance is most pronounced for polyps in the gastrointestinal tract or bladder. An acaulous (sessile) polyp is a flat, broad-based lesion, making it harder to detect during endoscopy. Its complete removal (polypectomy) is technically challenging, increasing the risk of incomplete resection. This elevates the risk of recurrence and malignant transformation, directly impacting patient prognosis and surveillance strategies. It is a critical descriptor for procedural planning and risk assessment.

Related Conditions

The term is relevant to conditions with sessile growths, most notably Colonic Polyps, including precancerous Sessile Serrated Adenomas/Polyps (SSA/Ps). Other examples include Bladder Polyps and Uterine Polyps presenting without a stalk. In dermatology, some warts are acaulous. The term is also used in mycology to describe fungal colonies growing directly on a substrate without a stipe.

Key Takeaways

• Definition: Acaulous means “stemless” or “sessile,” describing a structure attached directly by its base.
• Clinical Context: Primarily describes the flat morphology of polyps, distinguishing them from stalked (pedunculated) growths.
• Procedural Impact: An acaulous morphology complicates detection and removal, influencing cancer risk and management.

Note: This content is for informational purposes only and does not substitute for professional medical advice. Always consult your doctor for diagnosis and treatment.