Lobular neoplasia found on breast biopsy: marker of increased risk of malignancy or direct pre-cancerous lesion?

The aim of this study was to compare the imaging symptoms and microscopic findings in females with lobular neoplasia (LN) found on biopsy. 1,478 women who underwent primary open biopsy or surgical excision after percutaneous biopsy were reviewed. In 24 of them (1.6%), LN was found. In four patients, excisional biopsy with hook-wire localization was done primarily due to the radial scar. In 20 females, surgical excision of BIRADS 4 lesion was performed because of the presence of LN in specimens from the vacuum-assisted or core-needle percutaneous biopsy. Postoperative pathologic findings were compared to the radiological symptoms. In 13 women, LN did not produce any radiological symptoms and was an additional histologic finding existing near the other lesion: fibroadenoma and radial scar. In none of these lesions was an invasive cancer noticed. In one single patient, ductal carcinoma in situ was observed in the other segment of the breast. Invasive ductal cancer developed in the contralateral breast in one patient. In 11 patients, LN was diagnosed due to radiological symptoms produced by itself. In this group, the invasive lobular cancer was found in seven lesions (64%). Our finding suggests that LN producing suspicious radiological symptoms can be a different biologic type of this lesion when compared asymptomatic LN diagnosed which is usually found on biopsy as additional microscopic pathology. Symptomatic LN is probably associated with a higher potential of malignant transformation.