Triple-Negative or Close-to-Triple-Negative Breast Cancer Presenting as a Thick-Walled Cystic Lesion.

Clinical and pathologic characteristics of the invasive ductal carcinoma (IDC) presenting as a thick-walled breast cyst are little known. Three female patients were included in this report. A palpable, nontender breast lump was found in all cases. While mammography showed a hyperdense mass, ultrasonography demonstrated a thick-walled cystic mass. Magnetic resonance imaging clearly showed the cystic breast lesions with ring-like or irregular rim enhancement. A grade III IDC was confirmed in all cases. All IDCs but one were estrogen receptor negative, progesterone receptor negative, and human epidermal growth factor receptor 2 negative, with merely weak progesterone receptor positivity (5%) in one case. All cases underwent surgical management first and postoperative chemotherapy. Breast malignancy presenting as a thick-walled cystic mass could be a highly aggressive IDC, even triple-negative breast cancer. It is imperative for breast cancer-related practitioners to identify the potentially malignant cystic lesions timely and adopt appropriate management.