<s>[INST] context: CSDT writes - "Unilateral, spontaneous, serious or serosanguineous discharge from a single duct is usually caused by an intraductal papilloma or rarely, by intraductal cancer."
Mostly the underlying cause is a duct papilloma or duct ectasia, but since the chances of malignancy are high, it must be investigated further. The risk of malignancy increases if an underlying mass is present.
Investigation used are

Mammography - can show any underlying suspicious lesion.
Cytological examination - this may identify malignant cells, but a negative finding does not rule out cancer.
Galactography/Ductography.


The primary indication for ductography is nipple discharge, particularly when bloody.
Ductography though helpful in reaching a diagnosis is not essential since excision of the bloody duct system is indicated regardless of finding.
In this study, a contrast medium is injected into the discharging duct and a mammogram taken. The injected may show an intraductal papilloma as a filling defect surrounded by contrast. Cancers may appear as irregular masses or as multiple intraluminal filling defects, or abrupt obstruction. Duct ectasia or fibrocystic disease may appear as dilated cystic structures.
Ultrasound - may show the presence of an underlying mass or duct ectasia.
The final diagnosis is made by excising the involved duct (Microdochotomy) and any underlying mass if present and subjecting them for a histopathological diagnosis.
Radical duct excision (meaning removal of all lactiferous ducts) is not done. [/INST] question: A 25 year old Female complains of discharge of blood from a single duct in her breast. The most appropriate treatment is : | options: A: Radical excision B: Microdochectomy C: Radical mastectomy D: Biopsy to rule out carcinoma | answer: B </s>