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Brooke–Spiegler Syndrome
Published in Dongyou Liu, Handbook of Tumor Syndromes, 2020
Trichoepithelioma (cribriform trichoblastoma or follicular tumor) is a benign neoplasm that presents as firm, elevated, flesh-colored nodules of <2 cm in diameter in the head and neck region as well as midface (mainly on the nose and nasolabial folds) in adolescence or adulthood. The defining lesions of MFT are bilaterally and symmetrically distributed, flesh-colored papules or small nodules on the face (especially the nose), neck, or chest. Histologically, trichoepithelioma is a symmetric lesion showing dual differentiation toward follicular germinative epithelium and specific follicular stroma. While the epithelial component comprises bland basaloid cells arranged in a cribriform pattern, the stroma includes delicate fibrillary collagen bundles and numerous spindled fibroblasts, resembling follicular papillae (papillary mesenchymal bodies) and perifollicular sheath. Trichoepithelioma related to MFT may consist of areas with ductal differentiation and intratumoral lymphocytes, resembling a spiradenomatous moiety (Figure 36.4) [25,26].
Trichoblastoma
Published in Longo Caterina, Diagnosing the Less Common Skin Tumors, 2019
Trichoblastoma is a rare benign tumor of the hair germ, mainly composed of follicular germinative cells. Together with the syringocystadenoma papilliferum, it is the most common benign tumor arising in organoid (sebaceous) nevus.1 Clinically, it generally appears as a slow-growing nodule of the head and neck, greater than 1 cm in diameter. Several variants of trichoblastoma have been described, including pigmented, giant, clear cell and adamantanoid. Of note, trichoepithelioma could represent a superficial (intradermal) and differentiated variant of trichoblastoma.2
Multiple secondary neoplasms in nevus sebaceus excision
Published in Baylor University Medical Center Proceedings, 2022
Travis S. Dowdle, David A. Mehegran, Dylan Maldonado, Cort D. McCaughey
Nevus sebaceus is of particular clinical interest because of its association with the development of secondary neoplasms of varying rarity. Secondary tumors are typically benign, but malignant neoplasms have also been observed. The most common benign neoplasms include trichoblastoma and syringocystadenoma papilliferum. Additional benign neoplasms such as apocrine/eccrine adenoma, trichilemmoma, and sebaceoma have been observed.3 It has been estimated that approximately 40% of syringocystadenoma papilliferum lesions are associated with nevus sebaceus.4
Basal cell carcinoma within nevus sebaceous of the trunk
Published in Baylor University Medical Center Proceedings, 2019
Ian T. Watson, Andrew DeCrescenzo, So Yeon Paek
Trichoblastoma (34.7%), syringocystadenoma papilliferum (24.7%), apocrine adenoma (10%), and trichilemmoma (5.3%) are the most common secondary neoplasms found within NS.2 The incidence of BCC in NS is about 1%, making it the most common secondary malignancy.2 In one report of 65 NS tissue samples, 95% of lesions displayed HRAS gene mutations and 5% had a KRAS mutation. These oncogenic mutations may explain a predisposition to the development of secondary tumors because additional genetic “hits” occur later in life.3