Fig. 1

Histological and immunohistochemical features of the tumour. a Infiltrates of secretory carcinoma show microcystic to reticular and focally tubular growth and moderate nuclear pleomorphy with accompanying desmoplastic stromal reaction (HE staining). b Focal intra- and extracellular PAS-positive mucin production is recognized (PAS staining). c Focal expression of S100 protein. d Mammaglobin expression in part of tumour cells