Mitosis Detection in Breast Cancer Histological Images

IPAL UMI CNRS — TRIBVN — Pitié-Salpêtrière Hospital — The Ohio State University

General Description of the Problem

Nottingham Grading System is an international grading system for breast cancer recommended by the World Health Organization. It is derived from the assessment of three morphological features: tubule formation, nuclear pleomorphism and mitotic count. Several studies on automatic tools to process digitized slides have been reported focusing mainly on nuclei or tubule detection. Mitosis detection is a challenging problem and has not been addressed well in the literature.

Mitotic count is an important parameter in breast cancer grading as it gives an evaluation of the agressiveness of the tumour. Detection of mitosis is a very challenging task since mitosis are small objects with a large variety of shape configurations. The four main phases of a mitosis are prophase, metaphase, anaphase and telophase. The shape of the nucleus is very different depending on the phase of the mitosis. On its last stage, the telophase, a mitosis has two distinct nuclei, but they are not yet full individual cells. A mitosis in telophase must be counted as a single mitosis, it should not be miscounted as two mitosis. Artefacts are also common and should not be confused with mitosis. Figure 1 shows some examples of possible mitotic phases.

Figure 1: Some examples of mitotic phases.

Prophase mitotic cellProphase

Metaphase mitotic cellMetaphase

Telophase mitotic cellTelophase

The objective of the contest is to detect mitosis on H&E stained histological images of different breast cancers.

Contest Description

The competition consists in being able to tell what is the mitotic count on an image. Different types of images are provided. The contestants can take advantage of using the information of some of the spectral bands which may be more discriminating for the detection of mitosis, or to concentrate only on RGB images.

The result of the detection should be a text file (CSV type) containing the list of pixel coordinates of all the pixels covering the detected mitosis areas (the origin point of an image is at the top left corner of the image). One line of the file contains the list of all pixels coordinates of a single mitosis.