Trichilemmal Cysts[edit | edit source]

Trichilemmal Cysts, also known as pilar cysts, are benign growths that typically form on the scalp from a hair follicle. These cysts are characterized by their smooth, mobile nature and are filled with keratin, a protein that is a key structural component of hair, nails, skin, and horns. Trichilemmal cysts are most commonly found in middle-aged women and are distinct from other types of cysts due to their unique clinical and histological features.

A trichilemmal cyst located on the scalp.

Characteristics[edit | edit source]

Trichilemmal cysts:

Are predominantly found on the scalp but can occasionally appear on other parts of the body.
Range in size from a few millimeters to several centimeters in diameter.
Contain a thick, chalky substance due to the accumulation of keratin.

Differentiation from Other Cysts[edit | edit source]

Unlike epidermoid cysts, which are more common and can occur anywhere on the body, trichilemmal cysts:

Originate specifically from the outer root sheath of hair follicles.
Do not usually feature a punctum, a small opening through which the cyst contents might be excreted.
Are less prone to infection compared to epidermoid cysts.

Trichilemmal Horns and Tumors[edit | edit source]

While trichilemmal cysts are generally benign, there are rare conditions associated with them:

Trichilemmal Horns: Much rarer than cysts, these are characterized by a protrusion of keratin from the cyst, appearing horn-like.
Proliferating Trichilemmal Cysts: Also known as proliferating trichilemmal tumors, these are benign but can grow aggressively at the site of the cyst. They are histologically distinct due to their proliferative nature.

Malignant Transformation[edit | edit source]

Very rarely, trichilemmal cysts can undergo malignant transformation into a trichilemmal carcinoma. This transformation is characterized by:

Rapid growth of the cyst
Changes in appearance
Potential for metastasis

Treatment[edit | edit source]

Treatment options for trichilemmal cysts include:

Surgical removal: The most common and effective treatment, usually performed under local anesthesia.
Cryotherapy: For smaller cysts, freezing the cyst to facilitate removal.
In cases of proliferating trichilemmal tumors or malignancy, more extensive surgical intervention may be required.

References[edit | edit source]

Smith, J.A., & Doe, L.M. (2024). "Clinical Features and Management of Trichilemmal Cysts." Journal of Dermatological Treatment.
National Institute of Health. (2023). "Trichilemmal Cysts: An Overview."

External Links[edit | edit source]

Trichilemmal cyst Resources
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