DCIS

More than 90% of the cases entered into the Sloane Project are of DCIS. This page gives relevant extracts from the Sloane Pathology Form, examples of the main patterns seen in your practice and also some side-by-side images to act as an aide memoire for grading. There will always be an element of subjectivity at the grade 'boundaries' but it is hoped that we can help reduce the inter-observer variability by providing guidance notes and high quality images to illustrate the points.

Growth Pattern

Solid DCIS (example 1)

Cribriform DCIS (example 1)

Cribriform DCIS (example 2)

Cribriform DCIS (example 2)

Micropapillary DCIS (example 1)

Papillary DCIS (intracystic papillary carcinoma) (example 1 - macro)

Papillary DCIS (intracystic papillary carcinoma) (example 1)

Apocrine DCIS (example 1)

Apocrine DCIS (example 2)

Clinging DCIS (example 1)

Clinging/Flat DCIS (example 2)

Grading

College of American Pathologists Guidelines for grading DCIS:

• Grade 1:
• Monotonous nuclei, 1.5 to 2.0 RBC diameters
• finely dispersed chromatin & only occasional nucleoli
• Grade 2:
• Neither nuclear grade 1 nor nuclear grade 3
• Grade 3:
• Markedly pleomorphic nuclei, usually greater than 2.5 RBC diameters
• coarse chromatin & prominent or multiple nucleoli

In the following series of six combination photos all the images have been photographed using a x40 objective on the same microscope. Every effort has been made to ensure that during the assembly of the images the magnifications remain comparable and unaltered.

Grading DCIS - Combination photo showing three separate examples of low grade DCIS

Grading DCIS - Combination photo showing three separate examples of intermediate grade DCIS

Grading DCIS - Combination photo showing three separate examples of high grade DCIS

Grading DCIS - Low grade left hand panel, high grade right hand panel

Grading DCIS (Micropapillary DCIS) - Low grade left hand panel, high grade right hand panel

Grading DCIS - Low grade left hand panel, high grade right hand panel

Paget's Disease

Paget's disease of the nipple

Microinvasion

• Microinvasion is uncommon and usually seen in association with high grade or comedo DCIS



• To qualify as microinvasive it is necessary:



1. To demonstrate carcinoma cells outside the specialised periductal stroma



2. That the size of each such focus is < 1mm


• Microinvasive carcinoma cells are distributed singly and when in small groups have an irregular outline



• The presence of periductal chronic inflammation and fibrosis is often a pointer to lurking microinvasive cells



• Immunostains are helpful both in detection and confirmation of microinvasion:



• A pan cytokeratin marker helps to pick out the cells as irregular groups or single cells - they can be very subtle on an H & E



• A myoepithelial marker such as CK 5/6 will demonstrate the absence of such a layer around the suspect cells



• If you are cutting levels to pursue a suspect focus ask for any immunostains either before the levels or between them depending on whether you have already reached the suspicious focus or alternatively are not quite there

High grade comedo DCIS and microinvasion - 'Mouse over' for high power view

High grade DCIS and microinvasion (example 2)

High grade DCIS and microinvasion (example 2) CK 5/6 immunostain
Note the foci of microinvasive carcinoma (labels A & B) and the apparent breach of the basal layer with protruding carcinoma into specialised stroma (arrow)

Assessing receptor status in DCIS