What are Trichoepitheliomas/ Trichoblastomas?
Trichoepitheliomas /trichoblastomas are benign adnexal tumors that exhibit biphasic differentiation, meaning they develop towards both follicular germinative epithelium and follicular papillae.
These tumors are usually sporadic and are not known to be familial, occurring independently without a known genetic predisposition in most cases.
What syndromes are associated with Trichoblastomas?
They are associated with Brooke-Spiegler syndrome and multiple familial trichoepithelioma, which involve CYLD mutations.
How are Trichoblastomas molecularly distinguished from basal cell carcinomas?
Trichoblastomas lack PTCH mutations, which helps differentiate them from basal cell carcinomas at the molecular level.
What is the typical demographic affected by Trichoblastomas?
Trichoblastomas usually affect individuals in their 5th and 6th decades of life. However, tumors associated with syndromes typically appear around puberty, with an equal predilection between males and females.
Where on the body are Trichoblastomas commonly found?
These tumors are most commonly found on the scalp, head, and neck but can occasionally appear on the trunk, extremities, and even the genital area.
What are the microscopic features of Trichoblastomas?
These tumors are well-circumscribed and located in the superficial dermis.
They contain nests of basaloid cells with peripheral palisading.
They are supported by a fibrous cellular stroma.
Papillary mesenchymal bodies, which are clusters of fibroblastic cells, may be seen.
Mitoses and apoptosis are present with minimal pleomorphism.
Keratin horn cysts may occasionally be observed.
What are the differential diagnoses for Trichoblastomas?
Nodular Basal Cell Carcinoma: This differs as it shows an epidermal connection with cellular pleomorphism and clefting between epithelial and stromal components, along with mucin.
Infundibulocystic Basal Cell Carcinoma: This condition predominantly shows basaloid nests with prominent follicular differentiation, less developed stroma, and clefting between epithelial and stromal components.
What is the recommended treatment for Trichoblastomas?
The recommended treatment is surgical excision, which involves removing the tumor from the skin to prevent any potential complications or recurrences.
