177 Background: Pleomorphic lobular carcinoma in situ (PLCIS) is an increasingly diagnosed variant of lobular carcinoma in situ. Histologically, it resembles ductal carcinoma in situ (DCIS), leading to controversy over proper management. Yet, the natural history of PLCIS is unknown. Here we describe our experience with PLCIS. Methods: Review of pathology reports (1995–2012) identified 233 cases of LCIS variants. Patients with synchronous ipsilateral DCIS or invasive cancer (IC) were excluded leaving 25 cases for review. Consensus review by 3 pathologists further excluded 7; leaving 18 cases, 12 of which were classified as PLCIS and 6 as LCIS with pleomorphic features (LCIS-PF). (Table) PLCIS was defined by cellular dyshesion, nuclear pleomorphism with a 2-3 fold size variation, conspicuous nucleoli, mitoses and abundant cytoplasm; lesions not meeting all parameters were classified as LCIS-PF. Loss of e-cadherin was confirmed; clinical data were obtained from medical records. Results: Mean patient age at diagnosis of PLCIS/LCIS-PF was 57 yrs (42-67 yrs). All cases presented with imaging abnormalities. A previous history of breast cancer was present in 7/18 (39%) pts (3/7, ipsilateral; 4/7, contralateral). Following PLCIS/LCIS-PF diagnosis, 6/18 (33%) pts underwent mastectomy and 12/18 had excision alone, with (n=3) or without chemoprevention (n=9). Margin status was negative in 4/12 pts; close in 3/12 pts and positive in 5/12 pts undergoing excision. At a median follow-up of 27 mos (2-148 mos), 2/12 pts treated with excision developed ipsilateral breast cancer (1 DCIS; 1 IC). Both had close margins at initial excision; median time to cancer, 54 mos. Conclusions: Pure PLCIS is an uncommon lesion. Synchronous malignancy or prior history of breast cancer are often present in patients with PLCIS, contributing to the difficulty in determining the actual risk conferred by this lesion and appropriate management. Efforts to systematically characterize LCIS variants and prospective documentation of outcomes are needed to clarify the significance of these lesions. [Table: see text]
Trends in incidence, treatment, survival and subsequent breast cancer in lobular carcinoma in situ in the Netherlands: A population-based analysis
