Differential Expression of Claudin 1 and 4 in Basal Cell Carcinoma of the Skin

Table 1

Localization of claudin 1- and claudin 4-positive cells in normal skin and basal cell carcinoma.

Normal skin		Basal cell carcinoma
Location	Intracellular distribution	Location	Intracellular distribution
Claudin 1
Epidermis, basal to granular cell layer (staining intensity is strongest in pickle cell layer)	Membrane^※	Majority of neoplastic cells (staining intensity is attenuated in the central area of tumour nests)	Membrane and cytoplasm
Myoepithelial cell of sweat gland	Membrane and cytoplasm
Sebaceous cell of sebaceous gland	Membrane
Hair follicle	Membrane^※
Claudin 4
Epidermis, granular layer	Cytoplasm	Neoplastic cells showing glandular or adenoid cystic structure, sebaceous or keratinizing in the central area of tumour nests	Membrane and cytoplasm
Myoepithelial cell of sweat gland	Membrane and cytoplasm
Sebaceous cell of sebaceous gland	Membrane
Hair follicle	Membrane and cytoplasm

^※inner root sheath of hair follicle and small population of pickle layer showed positivity in cytoplasm along with membrane.