Whole Breast Invasive Lobular Carcinoma Not Detected Radiographically.

Breast cancer is the most commonly occurring cancer in women, with invasive lobular carcinoma being the second most common histologic form. A 78-year-old female patient presented complaining of an enlarged palpable lymph node in the left axilla. Breast ultrasound, digital mammography, and contrast-enhanced spectral mammography (CESM) revealed no abnormal findings. Core needle biopsy of the lymph node revealed infiltrative, diffuse neoplastic growth suggestive of adenocarcinoma, indicating that the primary site should be sought in the breast. The patient underwent mastectomy and the histopathology was suggestive of invasive lobular carcinoma throughout the whole extent of the breast parenchyma. Breast cancer should be definitely included in the differential diagnosis of enlarged axillary lymph nodes, even if there is no other clinical or radiographic presentation of breast disease.