Abstract
PURPOSE: It is clinically difficult to differentiate between primary lung cancer (PLC) and metastasis from breast cancer (MBC) in the diagnosis of a solitary pulmonary nodule (SPN) observed in a patient with past history of breast cancer. We evaluated several clinical, radiological and pathological variables in patients with SPN in an attempt to identify reliable markers to differentiate them. METHODS: Retrospectively we reviewed the clinical, radiological and pathological characteristics of 64 patients with a history of breast cancer resection who subsequently underwent surgical resection of an indeterminate SPN in our institute. RESULTS: The patients with MBC were significantly younger (p = 0.01). Among CT findings, presence of a solid opacity (p <0.01), well-defined tumor (p <0.01) and absence of an air bronchogram (p <0.01) were significantly associated with MBC. Among the intraoperative frozen section pathologic findings, the absence of lepidic or papillary patterns (p <0.01) and the presence of strong fibrosis in the tumor (p <0.01) were significantly correlated with MBC. CONCLUSION: Although some cases are difficult to confirm the definitive diagnoses of SPN, combining CT and intraoperative pathological findings might enable us to distinguish SPN between MBC and PLC prior to postoperative examinations.