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

The second population

Unit 2 of 8

Find the second, smaller, darker population inside the fragments and in the background, and notice when it has gone.

A benign breast fragment carries two populations: the ductal epithelial cells, and a second, smaller, darker population among them. Stripped nuclei of that second population lie loose in the background. When they thin out or vanish, the reading changes.

Nothing on this site labels that second population. The pipeline segments nuclei; it does not tell one kind from another. So this unit is your eyes against the expert's category, and the feedback shows you the category, the report line and the criteria, never a claim about the patch.

The Masood score below is the scaffold that makes your reading explicit. You score the six parameters yourself, and the drill compares only your band with the expert category.

The criteria, quoted

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.

A cytologist would look for

  • predominantly large cohesive three-dimensional tissue fragments and flat mono-layered sheets
  • evenly spaced ductal epithelial cells with myoepithelial cells creating a bimodal pattern
  • bare bipolar nuclei representing stripped myoepithelial nuclei, in the background

C5 Malignant

An unequivocal statement that the material is malignant, and the type of malignancy identified should be stated whenever possible.

Risk of malignancy
99 to 100 percent
Management
If the triple test is concordant, proceed to definitive management; if discrepant, CNB or excision biopsy is mandatory.

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

The modified Masood score

A cytologist would look for each of these six parameters and score it from 1 to 4, then read the total against the bands below. You score it yourself. The parameter scores have no answer key here, so the drill compares only your band with the expert category of the patch.

Parameter1234
Cellular arrangementMonolayerNuclear overlappingClusteringLoss of cohesion
Cellular pleomorphismAbsentMildModerateConspicuous
Myoepithelial cellsManyModerateFewAbsent
AnisonucleosisAbsentMildModerateConspicuous
NucleoliAbsentMicronucleoliMicro or rarely macronucleoliPredominantly macronucleoli
Chromatin clumpingAbsentRareOccasionalFrequent
  • 6 to 8Non-proliferative breast disease
  • 9 to 14Proliferative disease without atypia
  • 15 to 18Proliferative disease with atypia
  • 19 to 24Carcinoma in situ or carcinoma

Modified Masood scoring system for breast fine needle aspiration cytology (six parameters scored 1 to 4).

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

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Start the session

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