Trichoadenoma

Trichoadenoma is a rare, benign tumor that originates from the hair follicle. It was first described by Nikolowski in 1958. Trichoadenoma predominantly affects the facial region, particularly the nose, and is more common in women than in men.

Clinical Features

Trichoadenoma presents as a solitary, well-circumscribed, skin-colored or slightly pigmented nodule. The size of the nodule can range from a few millimeters to several centimeters. The surface of the nodule is usually smooth, but it can also be slightly verrucous. The lesion is typically asymptomatic, but it can sometimes cause discomfort due to its location.

Histopathology

Histologically, trichoadenoma is characterized by numerous small, round to oval, epithelial nests in the dermis. These nests are composed of basaloid cells that resemble the outer root sheath of the hair follicle. The center of the nests often contains keratinous material, which is a characteristic feature of trichoadenoma. The surrounding stroma is usually fibrous and may contain a mild inflammatory infiltrate.

Diagnosis

The diagnosis of trichoadenoma is primarily based on histopathological examination. Other diagnostic methods, such as dermoscopy and immunohistochemistry, can also be used to support the diagnosis. Dermoscopy typically shows a homogeneous pattern with white areas, while immunohistochemistry reveals the expression of hair follicle-related markers in the tumor cells.

Treatment

The treatment of choice for trichoadenoma is surgical excision. The prognosis is excellent, as the tumor is benign and does not have the potential to metastasize. However, recurrence can occur if the tumor is not completely removed.

See Also

• Trichoepithelioma
• Basal cell carcinoma
• Hair follicle