Case 2 - Discussion

Uploaded: 2007-01-17, Updated: 2007-11-18

ER, 20 PR, 20
Ki67, 20  

Mucinous Carcinoma or Colloid Carcinoma of Breast

  • 1% to 6% of primary breast cancers in women 75 years or older;

  • Classified into pure and mixed types with areas of infiltrating ductal carcinoma;

  • For pure MCB, size does not correlate with metastasis, although smaller tumors carry an excellent prognosis;

  • The mucin is almost entirely extracellular;

  • The incidence of axillary metastases is very low in pure MCB;

  • 10-year survival rate: pure MCB, 90% to 100%;  mixed MCB, 60% ;

  • Differential diagnosis: 1, signet-ring carcinoma of the breast: the mucin is predominantly intracellular; 2, mucinous cystadenocarcinoma: tall columnar cells with abundant intracellular mucin.

  Personal Notes
  • Extensive sampling is necessary to search for possible concurrent ordinary invasive carcinoma;

  • Classical grading system can be used in this subtype of breast carcinoma.

  • Annals of Surgical Oncology 9:161-164 (2002)
  • Rosai and Ackerman's Surgical Pathology, 9th edition;