Trichoepithelioma vs Basal Cell Carcinoma

Comments:
Trichoepithelioma vs Basal Cell Carcinoma: Both tumors show nests of basaloid cells with peripheral palisading.

Features favoring trichoepithelioma: no surface ulceration, prominent epithelial fronds, dense connective tissue stroma with papillary mesenchymal bodies, CK15 positivity, bcl-2 positivity in the peripheral portion of the tumor, low MIB-1 proliferation index, lack of staining with p53, absence of androgen receptors, and the presence of CD34+ cells in stroma.

Features favoring basal cell carcinoma: surface ulceration, prominent tumor-stroma retraction artifact, mucin deposits, lack of CK15 staining, diffuse expression of bcl-2, high MIB-1 proliferation index, p53 staining, androgen receptor positivity, and absence of CD34+ stromal cells.