This image was taken from the wall of a long-standing inflamed hydrocele. The surface is denuded. The submesothelial tissue shows florid mesothelial hyperplasia consisting of arrays of widely-spaced simple elongated tubules and small solid nests and cords of cells. The stroma shows fibroblastic organization and chronic inflammation. Sometimes, these mesothelial-lined glandular structures are accompanied by stromal response and may be mistaken for invasive carcinoma. The other main differential diagnostic consideration is malignant mesothelioma.