History
Patients present with a papule on the face, usually localized to the nose. [7] They are also found on the malar/cheek area, ears, scalp, or neck. Although one report describes multiple lesions, folliculomas usually present as solitary nodules. Lesions are asymptomatic and slow growing, with a diameter usually of 0.2-1 cm. Lesions have a central punctum, in which patients may note the presence of a vellus hair protruding.
Physical Examination
A folliculoma is a solitary tumor, most commonly found on the face or occasionally the scalp, ears, or neck. One reported case describes a congenital folliculoma on the cheek. [9] Folliculomas have also been identified in the vulva [10] and on the abdomen. [11]
The lesion is a firm, slightly elevated, pearly tumor with a central punctum. The central punctum contains keratinous material or a wisp of white, wool-like or cottony hairs protruding from it. If hairs protrude from the punctum, the diagnosis of folliculoma is strongly suggested.
On dermatoscopic examination, a distinct "firework" pattern has been described. A central hair shaft and several smaller radial dark-brown projections are scattered peripherally that correlate to nests of cells of pigmented follicular epithelium. [12] Description of a second case was less specific, with a bluish nodule, shiny-white structures, dotted vessels, and some central scale. [13]
Complications
Folliculomas are completely benign growths. No cancerous tendencies have been reported and they are not usually associated with complications. Rarely this condition has been associated with focal acantholytic dyskeratosis. [14]
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Classic microscopic findings of a trichofolliculoma with smaller radially budding hair follicles opening to a large central follicle. A dense eosinophilic stroma surrounds the tumor (hematoxylin and eosin, 40x).
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Folliculosebaceous cystic hamartoma (sebaceous trichofolliculoma) is a variant of trichofolliculoma with extensive sebaceous differentiation in the follicular buds emerging from the larger central follicle (hematoxylin and eosin, 40x).
