Purpose: Patients with spontaneous nipple discharge (SND) who have neither clinically palpable masses nor evidence of disease on imaging with mammogram and/or ultrasound are traditionally investigated with galactogram and duct excision. As breast imaging improves, it has raised the question whether galactography and microductectomy are necessary to diagnose breast cancer. The purpose of this study was to determine the incidence of malignancy in patients presenting with SND who underwent microductectomy and to evaluate the utility of duct excision and galactography in patients whose initial clinical and radiological evaluation were negative.
Methods: A 10-year retrospective study was conducted in British Columbia's largest tertiary breast referral center examining the clinical, radiological and pathological results for all patients who underwent a microductectomy procedure for SND between 2008 and 2017.
Results: A total of 231 microductectomies were performed and the overall incidence of malignancy was 13% (n = 32). Following initial work up, 155 patients (67%) had only discharge on exam and no radiologically suspicious findings of malignant disease. Of these patients, 14% (n = 21) were diagnosed with cancer by duct excision. Galactography yielded a sensitivity and specificity of 63% and 36%, respectively (PPV 15% and NPV 85%). Lastly, we found that 3% of patients (n = 8) initially diagnosed with benign disease later developed breast cancer.
Conclusions: Patients with SND should continue to be evaluated with microductectomy to prevent missing a breast cancer. Moreover, we do not recommend performing galactography for diagnosing breast cancer due to poor sensitivity and specificity though it may assist in preoperative planning.
Keywords: Breast cancer; Breast imaging; Duct excision; Galactogram; Microductectomy; Nipple discharge.