Mucous metaplasia of epithelial cells in fibrocystic disease of the breast. A histochemical study.

Mucous metaplasia of breast epithelium was studied by histochemical procedures in cases of fibrocystic disease. Epithelial mucins consist almost entirely of non-sulfated sialomucins. A slight amount of sulfated sialomucins was identified occasionally while neutral mucins seems to be absent. Abundant glycogen granules are contained in the cytoplasm of metaplastic cells. The secretion of sialomucins may be associated with a loss of cell antigenicity. In this case, the survival of metaplastic epithelium supports the hypothesis of the possible immunological nature of the disease.