Unifocal versus multifocal breast cancer

Case contribution: Radhiana Hassan


  • A 43 years old
  • Complaint of right nipple retraction, no nipple discharge
  • No breast lump palpable
  • Initially thought change is due to breastfeeding a one year old child

Mammogram findings:

  • Bilateral dense breasts BIRADS C with slight asymmetry in density
  • There is right nipple retraction (arrows)
  • No obvious mass on digital mammogram images
  • However tomosythesis shows a focal stromal distortion in right upper quadrant
  • A clustered microcalcifications is also seen at right upper outer quadrant near axillary tail
  • No skin thickening. No abnormal axillary node.

Ultrasound findings:

  • Two suspicious lesions are seen in the right breast.
  • A lesion adjacent to right areolar region measures 8 mm in its largest dimension
  • It shows irregular outline with some posterior shadowing
  • Another lesion as same quadrant but further away near axillary region measuring 10×9 mm.
  • It shows irregular outline with papillary projection
  • It also shows posterior shadowing
  • No continuation of these two lesions are seen.

Progress of patient:

  • Biopsy shows invasive carcinoma
  • Surgical team inquired whether this is a unifocal or multifocal lesions as patient requested breast-sparing surgery
  • Based on imaging it was concluded as multifocal lesion.
  • Patient subsequently had right mastectomy and axillary clearance. HPE shows invasive carcinoma NST, Bloom and Richardson Grade 3, florid lymphovascular invasion, extensive DCIS component (50%), the closest DCIS margin is 1 mm from lateral margin and deep margin is 2 mm from the invasive component. Positive nodal metastasis in 6 out of 7 lymph nodes, ER/PR –ve, Cerb B2: +ve.
  • Conclusion: only one tumour identified based on gross and microscopic analysis of the specimen measuring 40x30x16 mm.


  • Presence of two or more foci of cancer within the same breast quadrant is defined as multifocal (MF)
  • Presence of two or more foci of cancer in different quadrants of the same breast is defined as multicentric (MC)
  • Some defined that the separation between two lesions should be more than 4 cm to be classified as MF/MC tumours
  • MF/MC have been reported in 40-70% in serial studies of mastectomy specimens
  • Usually a contraindication for breast-conserving surgery
  • MRI has been shown to have higher accuracy than mammogram/ultrasound assessment
  • TNM classification use only the diameter of the largest focus and may underestimates higher tumour burden of MF/MC breast cancers.
  • MF/MC cancers are biologically more aggressive than unicentric tumours with higher incidence of metastasis and related with worse outcome.



Author: radhianahassan