Histomorphological and Immunohistochemical Reappraisal of Cutaneous Adnexal Tumours: A Hospital Based Study
Table 7
Salient histopathological features of follicular tumours.
Proliferating trichilemmal tumour
(i) Tumour lobules of squamous epithelium (ii) Epithelium in centre abruptly changed into amorphous keratin (iii) Epidermoid keratinization resembling squamous eddies with nuclear atypia and individual cell keratinisation
Pilomatricoma
(i) Tumour made of epithelial islands in a cellular stroma, located in dermis containing two types of cells (ii) Basophilic cells round to elongated  (iii) Shadow cells that had distinct border with loss of nucleus and calcification seen
Trichilemmoma
(i) Verrucous hyperplasia with lobular formations extending into the dermis (ii) Many cells demonstrating clear cytoplasm (PAS positive)
Trichofolliculoma
(i) Keratin filled cysts lined by squamous epithelium (ii) Numerous secondary (immature) hair follicles emanating from the cyst wall
Trichoepithelioma
(i) Superficial dermal lesion with prominent stroma (ii) Horn cyst of variable sizes (iii) Basaloid epithelial formations (iv) No retraction artifact