2015 Volume 64 Issue 2 Pages 153-157
Case 1：A 72-year-old woman visited us with a complaint of right axillary lymph node swelling. Breast cancer metastases to the axillary lymph nodes were suspected. Even with mammography（MMG），ultrasound（US），computed tomography（CT），and magnetic resonance imaging（MRI），the primary lesion could not be identified. Axillary lymph node biopsy revealed invasive lobular breast carcinoma. She was diagnosed with latent breast cancer and underwent mastectomy and axillary lymphadenectomy. Case 2：A 60-year-old woman visited us with a complaint of right axillary lymph node swelling. Despite various examinations, including MMG, US, CT and MRI as in Case 1, the primary lesion could not be identified. Axillary lymph node biopsy revealed invasive ductal breast carcinoma, leading to a diagnosis of latent breast cancer. She underwent mastectomy and axillary lymphadenectomy. Postoperatively, both patients have remained recurrence-free for two years to date. Latent breast cancer develops at a low incidence, 0.3－1% of all breast cancers, and therapeutic strategies are determined on an individual basis at each institution. While insufficient treatment increases the possibility of recurrence and metastasis, excessive therapy should be avoided. Therefore, determining the optimal therapeutic strategy can be challenging. We advocate accumulating more cases to establish systematic therapeutic guidelines.
