Nestin and caveolin-1 in the diagnosis of GISTs

Gastrointestinal stromal tumors (GISTs) are the most common primary mesenchymal neoplasias of the gastrointestinal tract, typically expressing c-kit (CD117) and CD34. Recently, it was reported that nestin and caveolin-1 are also expressed in some human sarcomas, GISTs included. We performed a retrospective study on formalin fixed, paraffin embedded samples from 81 cases of confirmed GISTs, aiming to characterize their immunohistochemical profile, including nestin and caveolin-1 expressions. Tissue samples were evaluated immunohistochemically for CD117, CD34, nestin and caveolin-1. The patients (M:F 36:45), aged 46 to 84 years, had spindle cell type GISTs in 56.7% of cases, epithelioid in 30.8% and mixed pattern in 12.3%. Immunohistochemically, CD117 was positive in 88.9% of GISTs, CD34 in 85.1%, nestin in 77.7% and caveolin-1 in 71.6% of the tumors. Of nine c-kit negative GISTs, 66.7% expressed nestin, the same as caveolin-1 and 44.5% expressed both nestin and caveolin-1. Statistical analysis using Kendall's and Spearman's tests revealed significant correlations between nestin and caveolin-1 expressions (p=0.024). Our results suggest that nestin and caveolin-1 could be considered sensitive markers in GISTs, together with CD117 and CD34, for diagnostic purposes. Their significant expression in CD117 negative GISTs could represent an immunohistochemical alternative in establishing the diagnosis of these tumors.