Shinya Tajima

St. Marianna University School of Medicine, Japan

Title: Breast papillary lesions: benign to malignant

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Biography

I am Shinya Tajima MD, PhD from Japan. I was born in 1976 in Saitama near Tokyo. I graduated from Keio University School of Medicine. After graduated the university, working in Department of Pathology at the same institution. Then I learned general pathology. And I would like to be a specialist of breast pathology. I affiliated St. Marianna University School of Medicine which is the most breast operation number in Japanese university. I received PhD in Radiologic-Pathology from the same Graduate School of Medicine, Kanagawa, Japan. I was working at the Department of Pathology and Radiology of this latter institution. Now I am working at Department of Diagnostic Pathology of Shizuoka medical center.

Abstract

Breast papillary lesions reveal broad range. Benign are divided into intraductal papilloma (IDP), radial sclerosing lesions, subareolar sclerosing duct hyperplasia, cystic and papillary apocrine metaplasia, florid papillomatosis of the nipple, syringomatous adenoma of the nipple and others. Breast benign papillary lesions are many but most common and important lesion is IDP. And accurate diagnosis of IDP from malignancy (Ductal carcinoma in situ) is important.       

Here, in relation to IDP, we would like to present new concept of two papillary lesions at a glance IDP. In the past, lacking myoepithelial cells is thought to be invasion and means malignancy. Two cases of 68- (Case1) and 44-year-old (Case2) female are presented. They have abnormality in the breast. And they came to our hospital for further examination and treatment. Radiologically, malignancy could not completely excluded. Then, breast excision was performed. Histologically, both cases revealed papillary neoplastic lesions lined by fibrovascular core and nuclear inverse-polarity without atypia. Loss of myoepithelial cells was observed by HE, p63, and calponin. Previous report indicate CK5/6, ER, p63 and MUC3 are important for distinguishing between papillary lesions according to the differential index (based on Allred score) of ([ER total score] + [MUC3 total score])/([CK5/6 total score] + [p63 total score] + 1). Based on this analysis, our 2 cases had benign lesions. Additionally, the Ki-67 index was <1% in both cases, and no evidence of disease was observed minimum 62 months of follow-up for both cases, despite lack of additional treatment. Thus, we propose that lack of myoepithelial cells in papillary lesions do not necessarily indicate malignancy and thought to be benign. These lesions are reported and named “Nuclear inverse polarity papillary lesion lacking myoepithelial cells”. However, the name is too long and its distinctiveness and rare, someone think this tumor as “Tajima tumor” as for the advocator.