Pleomorphic lobular carcinoma in situ of the breast: clinicopathological review of 47 cases

AimsPleomorphic lobular carcinoma insitu (PLCIS) of the breast is a distinctive entity, but its behaviour and management are unclear. The purpose of this study was to review a relatively large number of cases and to evaluate the risk of recurrence. Methods and resultsCases of PLCIS (n=47) from a 12-year period were reviewed. The clinical, radiological and pathological findings were recorded. Immunohistochemistry for oestrogen receptor (ER), progesterone receptor (PR) and HER2 was performed. Thirty-one patients had no concurrent breast cancer or past history of breast cancer, and six (19.4%) of these had local recurrence; all tumours (four invasive carcinoma and two PLCIS) were ipsilateral. Younger age at presentation was a risk factor for local recurrence: patients with recurrence had a mean age (range) of 52.5years (44-59years), versus 60.6years (40-81years) for those without (P=0.03). Three of 31 patients were treated with radiation therapy (RT), and none of these developed local recurrence. PLCIS had an adverse ER/PR/HER2 molecular profile, with at least 41.2% of the cases overexpressing HER2. Moreover, at least 11.7% of the cases were triple-negative. ConclusionsThis study included the largest number of patients who had no concurrent breast cancer or past history of breast cancer with the longest clinical follow-up, providing insights into management practices for PLCIS and the risk of recurrence.