Educational demo. Not a medical device. Not for diagnostic use.

The nuclear membrane

Unit 4 of 8

Read the edge of the nucleus, and see what smoothness, concavity and concave points measure on the traced outline.

The pipeline traces each nucleus with 64 points. Three of the eight inputs are read off that outline. Smoothness is the local variation in radius length. Concavity is the severity of the concave portions of the outline. Concave points is how many of them there are.

Those definitions are the 1993 ones, so the numbers mean the same thing here as they did for the 569 patients the model was fitted on. The marks in the example below sit where the outline turns inward, which is what concave points counts.

Read the edge first with the outlines hidden, then turn them on. The drills ask it in that order for a reason.

The criteria, quoted

The high power criteria of a malignant aspirate

A cytologist would look for

  • high cellularity, prominent dispersal of single cells
  • crowded tissue fragments with overlapping nuclei
  • nuclear enlargement, anisonucleosis, pleomorphism of the nuclear margin, size and chromatin, hyperchromasia and prominent nucleoli
  • a greatly reduced number or total lack of myoepithelial cells associated with the epithelial tissue fragments, and scant or absent bare bipolar nuclei

C2 Benign

A benign breast FNAB diagnosis is made in cases that have unequivocally benign cytological features, which may or may not be diagnostic of a specific benign lesion.

Risk of malignancy
1.4 to 2.3 percent
Management
If the triple test is benign, no further biopsy is required; if clinical or imaging findings are suspicious, repeat FNAB or proceed to CNB.

Source: Field AS et al. The International Academy of Cytology Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy Cytopathology. Acta Cytologica 2019;63:257-273.

The worked example

Loading the case library.

What the machine sees

The eight inputs

worst radius
mean of the three largest nuclei's mean radius. Touches nuclear enlargement.
worst perimeter
mean of the three largest nuclei's perimeter. Touches nuclear enlargement.
worst area
mean of the three largest nuclei's area. Touches nuclear enlargement.
worst texture
standard deviation of grey values inside the three largest nuclei. Touches chromatin, in part.
worst smoothness
local variation in radius length, three largest nuclei. Touches pleomorphism of the nuclear margin.
worst concavity
severity of concave portions of the outline, three largest nuclei. Touches pleomorphism of the nuclear margin.
worst concave points
number of concave portions of the outline, three largest nuclei. Touches pleomorphism of the nuclear margin.
mean concave points
number of concave portions of the outline, every nucleus. Touches pleomorphism of the nuclear margin.

Not measured here:

  • cohesion and architecture (sheets, three-dimensional fragments, dispersal)
  • myoepithelial cells and bare bipolar nuclei
  • nucleoli
  • cellularity of the whole smear
  • the background (stroma, mucin, cyst fluid, pus, fat)
  • necrosis
  • mitoses

A reader who sees only the first column can be right about the size of the nuclei and wrong about the smear. That is why your call comes first and the model answers second.

Start the session

About 20 trials, 5 to 8 minutes. You can stop at any point.