Case number:	177
Age:	39
Clinical presentation:	Premenopausal woman with average risk of developing breast cancer presented with a left breast areolar nodule. On examination, there was expressible serous discharge from the left nipple.

Mammography:

Breast composition:	ACR category b (there are scattered areas of fibroglandular density)
Mammography features:

‣ Location of the lesion:	Left breast, central portion of the breast, anterior third
‣ Mass:
• Number:	1
• Size:	No mass
• Shape:	None
• Margins:	None
• Density:	None
‣ Calcifications:
• Typically benign:	None
• Suspicious:	None
• Distribution:	None
‣ Architectural distortion:	None
‣ Asymmetry:	Focal
‣ Intramammary node:	None
‣ Skin lesion:	None
‣ Solitary dilated duct:	None
‣ Associated features:	Solitary dilated duct

Ultrasound:

Ultrasound features: Intraductal lesion in solitary dilated duct in left subareolar region, lower outer quadrant at 5 o’clock

‣ Mass
• Location:	Intraductal lesion in solitary dilated duct in left subareolar region, lower outer quadrant at 5 o’clock
• Number:	1
• Size:	1.0 × 4.0 cm
• Shape:	Oval
• Orientation:	Parallel
• Margins:	Circumscribed
• Echo pattern:	Hypoechoic
• Posterior features:	No posterior features
‣ Calcifications:	None
‣ Associated features:	Solitary dilated duct
‣ Special cases:	None

BI-RADS:

BI-RADS Category: 4A (low level of suspicion for malignancy)

Further assessment:

Further assessment advised: Referral for cytology

Cytology:

Cytology features:

‣ Type of sample:	FNAC
‣ Site of biopsy:
• Laterality:	Left
• Quadrant:	Retroareolar lump
• Localization technique:	Ultrasound-guided FNAC of intraductal lesion
• Nature of aspirate:	Whitish
‣ Cytological description:	Smears are moderately cellular. Three-dimensional papillary groups with fibrovascular cores are seen. Flat sheets of ductal cells with myoepithelial cells are also present. Background shows foamy macrophages, apocrine metaplasia, and some inflammatory cells
‣ Reporting category:	Atypical, probably benign
‣ Diagnosis:	Papillary neoplasm, favour benign
‣ Comments:	None

Histopathology:

Microdochectomy

Histopathology features:

‣ Specimen type:	Microdochectomy
‣ Laterality:	Left
‣ Macroscopy:	Microdochectomy specimen (2.0 × 2.0 ×1.5 cm) with apex marked with suture. On opening, a dilated duct with a small polypoid nodule (0.8 × 0.7 × 0.4 cm) was seen
‣ Histological type:	Intraductal papilloma
‣ Histological grade:
‣ Mitosis:
‣ Maximum invasive tumour size:
‣ Lymph node status:
‣ Peritumoural lymphovascular invasion:
‣ DCIS/EIC:
‣ Margins:
‣ Pathological stage:
‣ Biomarkers:
‣ Comments:

Case summary:

Premenopausal woman presented with left breast, expressible serous nipple discharge. Diagnosed as left breast subareolar solitary dilated duct with intraductal lesion, BI-RADS 4A on imaging, as benign proliferative change on cytology, and as papilloma on histopathology.

Learning points:

Solitary intraductal papilloma in a large duct in the retroareolar region presents as a palpable areolar lump as seen in this patient. Spontaneous or expressible nipple discharge, which may be serous or bloody, is also a common clinical presentation.