Diagnostic accuracy of immunohistochemical markers in differentiation between basal cell carcinoma and trichoepithelioma in small biopsy specimens.

BACKGROUND

The distinction of trichoepithelioma from basal cell carcinoma in small superficial biopsies is important but often challenging. This has inspired many scientists to test the validity of immunohistochemical markers in the differential diagnosis.

OBJECTIVES

To develop an immunohistochemical protocol that helps in differentiation between both trichoepithelioma (TE) and basal cell carcinoma (BCC) with higher sensitivity and specificity.

METHODS

Using standard immunohistochemical techniques, we examined 10 TEs and 19 BCCs for the expression of CK19, Ki-67, androgen receptors (AR), CD10, and PHLDA1.

RESULTS

Immunoreactivity of AR, Ki-67, and CD10 in tumor cells was significantly higher in BCC than TE with a diagnostic accuracy in BCC of 75.5%, 75.8%, and 79.3% respectively, whereas immunoreactivity of PHLDA1 in tumor cells and stromal CD10 was significantly higher in TE than BCC with a diagnostic accuracy in TE of 100% and 82.8%, respectively. In contrast, immunoreactivity for CK19 showed no statistically significant differences between both tumors.

CONCLUSION

The analysis of CD10, Ki-67, and PHLDA1 can be used as a helpful immunohistochemical panel in the distinction between TE and BCC especially in small and superficial biopsies.