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Tricholemmoma and tricholemmal carcinoma and Cowden syndrome
Published in Longo Caterina, Diagnosing the Less Common Skin Tumors, 2019
Eugenia Veronica Di Brizzi, Simonetta Piana, Giuseppe Argenziano, Elvira Moscarella
Tricholemmal carcinoma occurs most commonly on the face, scalp or neck of the elderly as an asymptomatic exophytic or polypoid mass, sometimes associated with ulceration, scales and telangiectasia, or as an alopecic area. It is generally about 2 cm in diameter.7,8
Hair Morphology, Biogenesis, Heterogeneity, Pathophysiology and Hair Follicle Penetration
Published in Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters, Cosmetic Formulation, 2019
Alexa Patzelt, Jürgen Lademann
Several benign, semi-malignant or malignant skin tumours have their origin in hair follicles. Basal carcinoma, for example, has mutations of the patched gene. This gene is a tumour suppressor associated with the Sonic Hedgehog–patched signalling pathway, which is active in hair follicle morphogenesis (Misago et al., 2003). Basal carcinoma is thus considered to be a malignant neoplasm of abnormal follicular germinative cells (Misago et al., 2003). Other skin tumours with follicular origin are seborrheic keratosis, trichoepithelioma, trichoblastoma, pilomatricoma and tricholemmal carcinoma (Headington, 1976).
Malignant vascular, adnexal, and fibrous tissue tumors
Published in Iris Zalaudek, Giuseppe Argenziano, Jason Giacomel, Dermatoscopy of Non-Pigmented Skin Tumors, 2016
Aimilios Lallas, Elvira Moscarella
Trichilemmal carcinoma is a rare tumor that arises on sun-exposed areas, most commonly the face and ears. Dermoscopy of a single case revealed a polymorphous vascular pattern, in conjunction with whitish-yellow well-circumscribed areas and ulceration (Figure 28.7).1 Although unspecific features, a polymorphous vascular pattern and ulceration are usually associated with malignant tumors.
Malignant proliferating trichilemmal tumor of the scalp: report of 4 cases and a short review of the literature
Published in Case Reports in Plastic Surgery and Hand Surgery, 2022
Cemal Alper Kemaloğlu, Melikgazi Öztürk, Beyza Aydın, Özlem Canöz, Orhun Eğilmez
Another manifestation that can be confused with MPTT is pilomatrix carcinoma. It is a rare malignant hair follicle tumor that typically presents as a nontender, firm dermal swelling on the head and neck regions with vary in size from 1 to 10 cm. Histologically, pilomatrix carcinomas show proliferating atypical basaloid cells with an infiltrating border [24]. Necrotic areas and frequent mitoses are often seen. Unlike MPTT, multiple lobulated and bosselated expansive masses of squamous epithelium was not observed. Pilomatrix carcinoma composed mostly basaloid cells, shows infiltrating border and marked nuclear pleomorphism with prominent nucleoli. Most studies recommend complete excision with 5–30 mm excision margins to prevent recurrence [25,26]. Adjuvant radiation therapy should be generally reserved for recurrent disease or residual macroscopic disease. Finally, trichilemmal carcinoma, which can cause confusion because of the name resemblance, should also be mentioned. This tumor is a completely separate entity from the MPTT. Trichilemmal carcinomas develop from trichilemmomas and their clinical course is not as aggressive as MPTT [27].