However, malignant clear cell mesothelioma exhibits the following characteristics: malignant progression, always with ascites; a tendency to grow in the peritoneum; a nodular-like appearance; the presence of clear cells that are partially gland like; the edematous degeneration of papilloma epithelial cells; lipid accumulation in foam sample cells can occur; and immunohistochemically it is positive for CK and Vim. The gene discussed is VIM; the disease is papilloma.