Morphological examination of intracytoplasmic lumina of the breast lesions and its diagnostic significance

We morphologically examined the intracytoplasmic lumina (ICL) in tumorous lesions of the breast by imprint cytology. The ICL was demonstrated by staining with Papanicolaou, Periodic acid Shiff, Alcian blue, May Grünwald Giemsa and CEA staining using immunohistochemical methods. The ICL appeared as round or oval shaped vacuoles, ranging in size from 2 to 18μm (median, 5.9μm). The ICL was morphologically classified into two types. One was characterized by the presence (Type I) or absence (Type II) of secretory materials in the lumen. Electronmicroscopic examination of type I showed cytoplasmic vacuole with wellformed microvilli projecting towards the lumen and various amounts of secretory materials, whereas the type II had vacuole with only scanty microvilli. In cases of carcinoma of the breast, the ICL was observed in 51% of the cytological cases. On the other hand, the incidence of the ICL among non-malignant lesions was only 0.5%. The frequency of ICL was greater in cases of scirrhous carcinoma than those of the other type of carcinoma of the breast. These ICL may be a helpful cytologic feature in the diagnosis of breast carcinoma.