Mucins in prostatic intra-epithelial neoplasia and prostatic carcinoma.

A histochemical study of 27 well-differentiated prostatic carcinoma cases associated with prostatic intra-epithelial neoplasia (PIN) was carried out. In the histological areas examined a decreasing production of neutral mucin was found as follows: normal prostatic tissue (70%), prostatic carcinoma (55%), PIN 1 (50%), PIN 2 (30%) and PIN 3 (15%). A progressively increasing content of acidic mucin (AB 2.5) was observed in the areas of PIN 3 (25%), PIN 2 (35%) and prostatic carcinoma (70%), while it was absent in the areas of PIN 1 and normal prostatic tissue. Acidic mucin sulphated type (AB 1) was secreted only in PIN 3 (5%) and prostatic carcinoma (10%) areas. These data were correlated with the proliferative activity of PIN. It is postulated that the lower neutral mucin production by PIN 3 can be linked to the higher proliferative activity of this lesion. Moreover, the acidic mucin secretion by PIN and prostatic carcinoma is considered to be a further feature of these lesions.