A case of invasive micropapillary carcinoma diagnosed as breast cancer by mammotome^® biopsy for axillary lymph node metastasis of unknown origin

Abstract

We report a case of invasive micropapillary carcinoma (IMP) of the breast which was diagnosed as breast cancer by performing Mammotome^® biopsy for left axillary lymph node metastasis. The patient was a 62–year–old woman who visited the department of internal medicine in our hospital because of abnormal findings at a medical checkup for lung cancer in June 2005. A chest plain CT scan showed swelling of left axillary lymph node, and then she was referred to the surgical department for close exploration of breast cancer in July of the year. Mammography (MMG) revealed clustered circular microcalcifications of category 3 in the left AC area, but no tumor was demonstrated by ultrasonography of the breast. Hence we decided to follow her clinical course thereafter. MMG performed in February 2006 showed unchanged calcifications. Herical CT scan done on the same day showed scattered dotty images in the AC area of the left breast and swollen left axillary lymph node, but no tumor was identified. The lymph node swelling became prominent and metastasis was suggested, so that Mammotome^® biopsy was performed for the calcifications in the left AC area to search the primary lesion in May 2006. Papillary tubular adenocarcinoma was thus diagnosed. Following modified radical mastectomy, the histopathological diagnosis of the resected material was IMP.