LCIS
A non-invasive lesion that arises from the lobules and terminal ducts of the breast.
Pathophysiology
[edit | edit source]- Recognised by its conformity to the outline of the normal lobule, with expanded and filled acini
- Variant - pleomorphic LCIS - a distinct, more aggressive subtype
- Shows nuclear pleomorphism compared with classic LCIS
- One or more lobules are distended by discohesive cells with irregularly-shaped, high-grade nuclei
- May or may not be associated with comedonecrosis and calcifications
- Controversial, but some suggest it should be excised and treated like DCIS
- Florid LCIS is another more aggressive variant
Presentation
[edit | edit source]- Uncommon condition, predominantly seen in younger pre-menopausal women
- Often found incidentally on biopsy
- Does not manifest as palpable mass or microcalcifications on mammography
Treatment
[edit | edit source]- If found incidentally:
- If core biopsy only shows classic LCIS, and radiology is concordant, observe with clinical and imaging follow-up. Very low upgrade rates (<3%).
- Pleomorphic or florid LCIS should be excised to negative margins.
- Treatment options
- Close surveillance
- Annual mammography and consider annual MRI (ideally, alternate these every 6 months)
- Chemoprevention
- Significant risk reduction with SERMs or Ais (reduces 5-year risk of invasive cancer by about 50%)
- Bilateral mastectomy
- 90-95% risk reduction
- Consider for women with additional risk factors
- Close surveillance
Prognosis
[edit | edit source]- Typically thought of as a marker of increased risk of developing breast cancer in the future, however this is controversial
- Not currently considered to be a preinvasive breast cancer
- Estimated lifetime risk of developing breast cancer is 30-40% (applies to both breasts, but higher risk in ipsilateral breast). Sabiston quotes actuarial risk of getting cancer within 35 years of 21.4%.
- RR of 7 for breast cancer
- 40% of cancers subsequently developing in patients with LCIS were in situ lesions. The invasive cancers that DID develop were predominantly ductal and not lobular, and 50% occurred in the contralateral breast.