On the welcome page of the dictionary, three major sections are shown: Normal tissues, Cancer and Cell structure. Below the image of each section are links to introductory texts for i) normal tissue histology, ii) hallmarks of cancer, and iii) cell structure overview. For the cancer-section there is also a link to current cancer statistics (incidence, survival, etc) for Sweden and the rest of the world. Within each section there are direct links to histology descriptions of different tissue types and tumor forms as well as descriptions of cell structures.
For the 'Tissue & cell types' and 'Tumor' sections, tissue-slides stained with hematoxylin and eosin (HE) are shown at three different levels of magnification. On the top level, an overview of the whole tissue-sample is shown with boxes in black indicating where zoomed-in representative parts of the tissue are available for viewing. Clicking on these boxes will zoom in on that part to show tissue structures, cells and features in greater detail. Throughout these sections, arrows indicate relevant tissue structures, cell-types and other features.
For the 'Cell structure' section, immunofluorescent images of formaldehyde-fixed cell lines are shown. The various cell structures that are demonstrated are always shown in the green channel using an antibody found in the Human Protein Atlas. The antibody name is linked to the subcellular location summary page of the target gene. The other channels: nucleus, microtubules and endoplasmic reticulum, are always shown in the blue, red and yellow channels, respectively. The channels can be toggled on and off by clicking on the respective coloured button above the image. When applicable, the immunofluorescent images are complemented by immunohistochemically stained cells where the location of the particular cell structure is shown in brown.
A common feature for all sections is that a general descriptive text about the tissue, tumor-type or cell structure is provided when browsing a particular topic.
The breast consists of three main components, the skin, the subcutaneous adipose tissue and the functional glandular tissue that comprises both parenchyma and stroma. The collecting ducts open at the nipple through which the infant obtains milk at suckling. Below the nipple, the collecting ducts dilate to form the lactiferous sinuses. The breast is divided into 15-25 lobules, each based on a branching duct system that leads from the collecting ducts to the terminal duct-lobular units. The terminal duct-lobular units are the functional sites of milk production. Each collecting duct drains a lobe made up of 20-40 lobules. In addition to the glandular cells, the lobe is composed chiefly of adipose tissue and fibrous stroma ? referred to as the inter- and peri-lobular connective tissue.
In the nipple the stratified squamous epithelium from the surface extends into the collecting ducts for a variable short distance. There is then an abrupt change into the glandular epithelium that is present throughout the duct and lobular system. The glandular epithelium is composed of two distinct types of cells, the secretory or luminal cells and the myoepithelial cells. In the collecting ducts the lining cells are usually columnar whereas in the acini they are usually cuboidal. Two types of luminal secretory cells have been identified. Basal cells, which have relatively, clear cytoplasm and an oval nucleus lacking a visible nucleolus, and the superficial luminal cells with darker, basophilic cytoplasm. The myoepithelial cells usually form a discontinuous layer between the luminal secretory cells and the basement membrane. The myoepithelial cells appear small, flattened and with dark nuclei.
