LOBULAR CARCINOMA IN SITU: A Histological Study of 52 Cases

In 52 cases of lobular carcinoma in situ of the breast (LCIS) without simultaneous invasive carcinoma, the actual lesion and the adjacent breast tissue were evaluated histologically and the findings related to the overall occurrence of invasive breast carcinoma. No single histological parameter appeared to any significant degree in cases with invasive carcinoma, whereas, in a few instances, this was the case when certain parameters were found concurrently. However, with our present knowledge, the result of a histological subclassification of LCIS cannot be decisive in the choice of treatment. Out of the 52 cases, 49 had fibro-adenomatosis concurrently; of these, 6 were of a high degree of severity, 4 had fibroadenoma, 1 had papilloma, 8 had ductectasia, 5 non-specific mastitis and 2 fat necrosis. Only occasionally was intracellular mucin found in cases of LCIS, whereas PAS-positive material was frequent. In a few cases very large mast cells were seen in the adjacent stroma, but the significance of this finding remains unclarified.