Dermoscopy of Sporadic Multiple Trichoepithelioma

Sir, A 69-year-old female presented with multiple, asymptomatic lesions over the face for 5 years. Initially, lesions were on the forehead, which gradually increased to involve the bridge of the nose, malar, and postauricular area in the past 5 years. No history of recent drug intake or radiation exposure was present. No significant family history could be elicited. Cutaneous examination showed multiple discrete skincolored papules and nodules over the forehead, face, nasal bridge, malar, and postauricular area [Figure 1a-c]. Papules were firm, nontender, mobile, and nonadherent to the overlying skin. Palms and soles revealed no abnormality. Oral cavity, hair, and nail examination were normal. Routine blood investigations and systemic examination were normal.Figure 1: Multiple skin-colored papules and nodule present over the (a) forehead, face, nasal bridge (b) malar (c) postauricular areaDermoscopy performed using a firefly dermoscope under ×10 showed few arborizing vessels, multiple milia-like cysts, and rosettes with the whitish background [Figure 2].Figure 2: Dermoscopy showing arborizing vessel (white arrow), milia like cysts (yellow arrow) and with whitish background (black arrow)Histopathology from the lesion over the forehead revealed the presence of horn cysts of varying size formed by few layers of basaloid epithelial cells and a fully keratinized center. The stroma showed few basaloid epithelial islands and fibroblast. Acanthosis in the epidermis and mild inflammatory infiltrate in the dermis was present [Figure 3]. Findings were consistent with the diagnosis of trichoepithelioma. The patient was advised for cryotherapy; she took few sitting but then was lost in follow-up.Figure 3: Keratin cysts formed by few layers of basaloid epithelial cells stroma with acanthosis in epidermis and mild inflammatory infiltrate in dermis (H and E, ×4)Trichoepitheliomas (TE), a superficial form of trichoblastoma, are rare benign hamartomatous tumors originating from the pilosebaceous follicle. They are dermal tumors having focal continuity with the epidermis and are composed of immature islands of basaloid cells with focal, primitive follicular differentiation. The tumor cells form rudimentary hair follicles but do not form actual hair shafts. The gene for TE is located on chromosome 9p21.[1] TE can present as small, firm, rounded, and shiny papule or nodule, which may be of yellow, pink, or brown in color having solitary, multiple, and desmoplastic variants. Multiple trichoepitheliomas is inherited (Brooke–Spiegler syndrome) and is more common in females.[2] Solitary TE presenting more commonly are not inherited (sporadic) and are associated with deletions at chromosome 9q22.3. It is found more often in young adults over the middle face, neck, scalp or trunk, and nasal area due to the increased number of sebaceous glands.[3] Multiple trichoepitheliomas (MTs) emerge as multiple skin colored to pink, firm, and papulonodular lesions, mainly on the face. It gradually increases in number and size with age, occurring on both cheeks, eyelids, and around the nose, as was seen in our patient. Malignant transformation to basal cell carcinoma (BCC) is unusual and occurs late in the course of the disease. It forms a part of rare syndromes which include Rombo's syndrome and Basex syndrome. Trichofolliculoma is a solitary tumor which grow slowly on the face of the elderly. Our patient had multiple lesions over the face but did not have any positive family history. A similar case has been reported by Sanaa and Zahra also.[3] The firm, pearly skin-colored papules of MTs must be differentiated from the firm, red-brown, telangiectatic papules of angiofibromas seen in tuberous sclerosis complex. Individual lesions may be differentiated on the basis of clinical, dermatoscopy, and histopathology with various conditions [Table 1].[3–6]Table 1: Differential diagnosis of trichoepitheliomaDermoscopy of TE shows homogeneous brown areas, white globules, and arborizing vessels.[7] The present case showed arborizing vessels and milia-like cysts, as reported in the literature.[8] which correlates with the presence of keratin cysts in the histopathology. Histopathology shows horn cysts, tumor islands composed of basophilic cells of basaloid appearance arranged in the peripheral palisading pattern. These basophilic cells lack atypia and mitosis in contrast to BCC. Keratinization is abrupt and complete as opposed to horn pearls seen in squamous cell carcinoma. The islands can have a "paisley tie" appearance. The aggregations of basaloid cells are arranged in different morphologic patterns, for example, cribriform (classic) and columnar (desmoplastic). Treatment of TE includes surgical excision for solitary lesions. Chemical cauterization, laser resurfacing, electro-surgery, and dermabrasion can be used for multiple lesions. Recently, topical 5% imiquimod cream has been advocated as a useful treatment. Although rare, TE can develop high-grade carcinomas and mixed (epithelial/sarcomatous) tumors.[4] Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Authors' contributions Data acquisition: P.A.N; Data analysis: P.A.N; Manuscript preparation: P.A.N; Manuscript editing: D.P; Manuscript review: J.J.T. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.