Immunohistochemical investigation of suprabasin, isthmin-1, and podocalyxin immunoreactivity in basal cell carcinoma and trichoblastoma/trichoepithelioma

OBJECTIVE: Basal cell carcinoma (BCC) and trichoblastoma/trichoepithelioma (TB/TE) are skin tumors that may exhibit similar histopathological features. This study aimed to examine the immunoreactivity of suprabasin (SBSN), isthmin-1 (ISM-1), and podocalyxin (PODXL) BCC and TB/TE, and to evaluate the possible roles of these molecules in pathogenesis. MATERIALS AND METHODS: A total of 60 tissue samples were included in the study: 20 BCC, 20 TB/TE, and 20 healthy skin samples. Indirect immunohistochemical staining was performed using SBSN, ISM-1, and PODXL antibodies. A histoscore was calculated based on staining extent and intensity. Data were analyzed using SPSS 22.0 software, and p < 0.05 was considered statistically significant. RESULTS: The mean SBSN histoscores in the BCC, TB/TE, and control groups were 0.115 ± 0.036, 0.105 ± 0.022, and 0.410 ± 0.060, respectively. A significant decrease in SBSN immunoreactivity was observed in the BCC and TB/TE groups compared with the control group (p < 0.001). The mean ISM-1 histoscores were 0.385 ± 0.046, 1.815 ± 0.247, and 0.895 ± 0.187, respectively. A significant decrease was observed in the BCC group compared with the control group, whereas a significant increase was found in the TB/TE group (p < 0.001). The mean PODXL histoscores in the BCC, TB/TE, and control groups were 0.395 ± 0.035, 1.785 ± 0.283, and 0.105 ± 0.022, respectively. PODXL expression was significantly increased in the BCC and TB/TE groups compared with the control group (p < 0.001). CONCLUSION: In our study, SBSN did not appear to be a distinctive biomarker for BCC and TB/TE. However, ISM-1 and especially PODXL may contribute to the pathogenesis of BCC and may have potential utility in the diagnosis of BCC and TB/TE.