Objectives: To identify the types of the cells in a case of pilomatricoma and to evaluate the lesion's stage, the cells' proliferating rate and the associated inflammatory reaction.
Material and methods: The paraffin-embedded tissue was investigated by histological examination and by immunohistochemistry for the expression of some markers such as: cytokeratins, CD3, CD20, CD68, PCNA, CD34 II.
Results: The lesion presented the characteristic epithelial cells of a classical pilomatricoma: bazaloid cells, ghost cells and transitional cells. 10-15% of the bazaloid cells were PCNA+. The MNF 116 antibody labeled only some of the transitional and of the ghost cells. We found no CD3-positive cells and few CD20-positive cells. A marked inflammatory reaction was noticed, dominated by giant multinucleated cells, positive for CD68 and PCNA and a rich network of blood vessels with a high vascular density.
Conclusion: The histological pilomatricoma diagnosis was straightforward on the basis of the bazaloid and ghost cells presence. Immunohistochemistry brought additional data regarding the cells proliferation rate, the stage of the lesion and the intensity of the associated inflammation.