TRANSFORMING GROWTH-FACTOR-BETA AND BCL-2 DISTRIBUTION PATTERNS DISTINGUISH TRICHOEPITHELIOMA FROM BASAL-CELL CARCINOMA

BACKGROUND. Trichoepithelioma (TE) and basal cell carcinoma (BCC) have many features in common both clinically and histologically. Despite t hese many similarities TE and BCC represent different biological entit ies. OBJECTIVE. Recently, bcl-2 and CD34 have been reported as reliabl e markers in distinguishing the two types of tumor. Transforming growt h factor-beta (TGF-beta), a multifunctional regulator of both cell gro wth and differentiation, was evaluated in this study. METHODS. The imm unohistochemical expression of TGF-beta was compared with the distribu tion patterns of bcl-2 and CD34 in five sees, five TEs, and seven bord erline cases. RESULTS. All five TEs showed a diffuse cytoplasmic stain ing of tumor cells for TGF-beta, whereas four of five BCCs were TGF-be ta negative. Of the seven equivocal cases of TE/BCC, five tumors demon strated TGF-beta positivity in combination with negative bcl-2 stainin g corresponding to TE. The remaining two cases demonstrated the opposi te staining pattern, characteristic for BCC. CONCLUSION. The TGF-beta staining pattern appears to be a helpful additional marker together wi th bcl-2 in differentiating between TE and BCC. The demonstrated stain ing differences may relate to the distinct origin and biological behav ior of the two tumors and may therefore be of value in subsequent pati ent management. (C) 1997 by the American Society for Dermatologic Surg ery, Inc.