Hyaluronan, CD44 and hyaluronidase (HYAL) 1–2 stainings of benign (a-d) and dysplastic nevi (e-h), in situ melanomas (i-l), superficial (<1 mm, in m-p) and deep melanomas (>4 mm, in q-t) and lymph node (LN) metastases (u-x). Red arrows in (i) indicate the increased hyaluronan staining intensity of melanocytic cells and stroma of in situ melanoma, showing also intracellular staining of hyaluronan. Red arrow in (q) points to reduced hyaluronan staining and in (r) to reduced CD44 staining, while in (t) the arrow indicates the increased HYAL2 staining in deep melanomas. Black arrows in (h, l, p) indicate the increased HYAL2 staining in the melanocytic cells of dysplastic nevus (h), in situ melanoma (l) and superficial melanoma (p). White asterisk in (i) indicates strong hyaluronan staining in tumor cells in in situ melanoma, while in (q) the white asterisk shows the reduced hyaluronan staining of tumor cells in deep melanoma. White dash lines in (i-p) delineate the border between the tumor cells and the stroma in in situ melanomas (i-l) and encircle the invasive tumor cells in superficial melanomas (m-p). Scale bar in (a) 100 μm.