Prognostic significance of periodic acid-Schiff-positive patterns in primary breast cancer and its lymph node metastases.

Invasive ductal carcinoma is by far the largest histological subtype of breast cancer, but clinical behavior can differ greatly. Reliable morphological markers are, therefore, of invaluable help to distinguish between patients with good and poor prognosis. Histological patterns stained with periodic acid-Schiff (PAS) were previously shown to be of prognostic significance in cutaneous and uveal melanoma.