A subset of breast invasive ductal carcinoma with distinctive cytomorphology, aggressive clinical behavior, and unique immunologic profiles

BACKGROUND Invasive ductal carcinoma of the breast is a heterogeneous collection of divergent types of carcinomas. Some subtypes have been characterized by histologic observations. This study describes a distinctive subset recognized through cytomorphologic examination of breast carcinoma specimens obtained by fine-needle aspiration biopsies (FNAB). Identification of this subset is established further by analyses of its clinical and immunologic characteristics. METHODS One hundred patients underwent FNAB and were diagnosed with breast ductal carcinoma. These diagnoses were followed by surgical resections and histologic evaluation of tumors. Immunohistochemical analyses of estrogen receptor, progesterone receptor, Her2/neu, p53 protein, and Ki-67 were performed. Patient's age, race, and family history of breast carcinoma were obtained. The objective of the study is to identify a cytomorphologically distinctive, clinically relevant, subset of breast carcinomas. RESULTS A subset carcinoma was recognized by cytomorphologic examination of Pap-stained FNAB slides. This subset consisted of seven patients with a median age of 37 years. At the time of surgical resection, all patients had axillary lymph node metastases. Six of seven patients had distant metastases. Immunohistochemical studies revealed that all tumors are positive for p53 protein and negative for estrogen and progesterone receptors. CONCLUSION This study presented a unique subset of breast ductal carcinomas that involved young patients and had aggressive growth behavior. These tumors expressed p53 protein but not estrogen and progesterone receptors. Cancer (Cancer Cytopathol) 2002;96:294–300. © 2002 American Cancer Society.