🦹🏽‍♀️LCIS

Question 1

Overview of LCIS

Answer 1

Definition: spectrum of atypical epithelial lesions that originate in the terminal duct-lobular unit (TDLU)

• Include lobular carcinoma in situ (LCIS) and atypical lobular hyperplasia (ALH) – differentiated by only degree of proliferation
• ALH and LCIS are both non-obligate precursors and risk indicators of invasive breast cancer

Question 2

Types of LCIS

Answer 2

4 variants of LCIS:
- 🍊Type A
- 🍎Type B
- 🍊Pleomorphic LCIS
- 🍎Apocrine LCIS

can be differentiate by its cytoplasm, cell cohesiveness, calcification and necrosis, phenotype

Question 3

Presentation of LCIS

Answer 3

• No specific clinical features
• Usually not identified Clinically or on MMG.
• 🚨Incidental finding in biopsy for some other mass producing lesion.
• 70 - 90% multicentric, 90% bilateral

Question 4

Investigation of LCIS

Answer 4

Radiology
- No radiologic features specific to LCIS
- Microcalcifications are not commonly seen in LCIS

Question 5

Management of LCIS

Answer 5

• Incidental diagnosis during surgical excision – no further excision of classic subtype, no need to report on margin
• 🚨If Pleomorphic LCIS (PLCIS) detected on surgical margin, re-excision till clear margin advised due to higher risk with PLCIS
• If diagnosed on Core Needle Biopsy; all lesion should be term as Lobular Neoplasia (LN) – not to differentiate between ALH and LCIS
• Surgical excision indicated in case of LN diagnosed on CNB only if presence of PLCIS or radio-pathological discordance

-Low upgrade rate in case of classic LCIS (5%) vs PLCIS (25%)

• Confirmed pleomorphic → if at margin, re-excision to negative margin.
• Classical → no further resection even if at margin

Question 6

Surveillance for LCIS

Answer 6

Probability of developing invasive cancer by:
- 🍎13%: 10 years after a diagnosis of LCIS:
- 🍎26% by 20 years
- 🍎35% by 35 years.

• Surveillance – NCCN suggest clinical assessment and MMG (6-12 monthly). No routine MRI breast except in high risk patients (strong family history or BRCA mutation)
• Chemoprevention – Tamoxifen and exemestane proven to reduce development of IBC up to 50% and 65% respectively (NSABP P1, STAR-2, MAP-3, ASCO Guidelines)
• 🙅🏻‍♂️❌Risk reduction mastectomy – not indicated in current practice due to low occurrence of IBC in Lobular Neoplasia patients