Trichofolliculoma: A Confusing Benign Tumor Volume 1 - Issue 4

Sialiti S¹*, Belmourida S¹, Khallaayoune M¹, Znati K² and Senouci K¹

• ¹Department of Dermatology-Venereology, Ibn Sina University Hospital, Mohammed V University, Morocco
• ²Department of Anatomopathology, Ibn Sina University Hospital, Mohammed V University, Morocco

Received: November 22, 2020   Published: December 18, 2020

*Corresponding author:Sialiti Sanae, Department of Dermatology-Venereology, Ibn Sina University Hospital, Mohammed V University, Rabat, Morocco

DOI: 10.32474/TRSD.2020.01.000119

Abstract PDF

Trichofolliculoma is a rare adnexal tumor of unknown etiology, occurring mainly in adults. It presents clinically as a solitary flesh-coloured papule or nodule, sitting on the face and scalp area, with rarely extra cephalic localizations. Histologically, the characteristic finding of trichofolliculoma include a squamous epithelium lined keratin containing dermal cyst with radiating hair follicles from the cyst wall. We present a case of an adult male with trichofolliculoma located on the eyebrow, that has been surgically removed without reccurence.

Keywords: Trichofolliculoma; Benign tumor; Follicular hamartoma

Trichofolliculoma is a uncommon benign tumor, generally considered to be a hamartoma with a follicular differentiation. It mostly affects young people and has a predilection for the face and scalp area, in which it presents as a single papule or nodule with a central depression from which a tuft of thin and white hair emerges. In this case, we report a classic case of trichofolliculoma of the face in a young man

A 36-year-old patient, without any notable history, presented in our dermatology department for a lesion that appeared more than two years ago, located on the left eyebrow, without no associated functional signs which, however, caused a rather marked aesthetic discomfort.

Clinical examination showed a well-circumscribed, fleshcoloured nodular lesion of 6mm, painless on palpation and with a hole in the center from which emerges a tuft of thin and whitish hairs (Figure 1). A complete excision of the lesion was performed with an anatomopathological study revealing a well-limited nodular benign tumour proliferation at the periphery, centred by an infundibular invagination (Figure 2) on which immature follicular structures, in the form of small nodules of basaloid cells lacking cytonuclear atypia, are connected. The whole was covered with an acanthosic epidermis surmounted by an orthokeratosis with the presence of horny plugs (Figure 3). On the basis of this histological finding, the diagnosis of a trichofolliculoma was confirmed and no recurrence was noted during follow-up at five months.

Figure 1: Eyeborw flesh-coloured tumor with tuft of hair emerging from central depression

Figure 2: Histological section of a primary follicle with dilated pore.

Figure 3: Histological section showing several secondary follicles.

Described in 1944 by Miescher, trichofolliculoma is a rare benign adnexal tumor that grows at the expense of the hair follicle [1]. It is also described as a hamartoma of hair differentiation, which is easy to diagnose clinically due to its typical appearance. Usually presented as a single painless, papular or nodular, fleshcolored or pink, centered by a tuft of white hairs emerging from a central opening, which may be absent in atypical forms. This tumor frequently sits on the face with some atypical extra-facial localizations on the abdomen or scalp [2]. For some authors, it would be more of a follicular malformation than a tumor of the hair follicle itself, which would occur spontaneously, although a notion of prior trauma was reported in a few cases.

The differential diagnosis can be made with trichoepithelioma, keratoacanthoma, syringoma, sebaceous hyperplasia or basal cell carcinoma if there is no duct [3]. Histopathology shows a characteristic tumor finding consisting of a dilated central follicle corresponding to the primary follicle, lined with a thick wall into which secondary follicles with a highly variable differentiation [4], ranging from mature secondary follicles with hair to the anagen stage, and from a hair papilla to very immature structures, end in a thick wall [5]. Sometimes it may contain rudimentary sebaceous structures on the seborrheic areas. A routine surgical excision without margins remains the treatment of choice for trichofolliculoma, if the patient is requesting it or to establish the diagnosis in hairless forms [6].

Trichofolliculoma is a rare benign tumor with a good prognosis belonging to the group of adnexal tumors. Generally of typical clinical presentation, it should be evoked in front of any facial or scalp lesion with an emerging tuft of hair in the center.

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