Case number:	056
Age:	58
Clinical presentation:	Postmenopausal woman with average risk of developing breast cancer presented with blood-stained nipple discharge from the left nipple. Examination did not reveal significant lumps in either breasts or axillae.

Mammography:

Breast composition:	ACR category a (the breasts are almost entirely fatty)
Mammography features:

‣ Location of the lesion:	Left breast, lower outer quadrant at 5–6 o’clock, middle third
‣ Mass:
• Number:	Multiple small intraductal
• Size:	Not measurable
• Shape:	Indistinct
• Margins:	Obscured
• Density:	Equal
‣ Calcifications:
• Typically benign:	None
• Suspicious:	None
• Distribution:	None
‣ Architectural distortion:	Present
‣ Asymmetry:	Focal
‣ Intramammary node:	None
‣ Skin lesion:	None
‣ Solitary dilated duct:	Multiple dilated ducts
‣ Associated features:	Architectural distortion with linear opacities

Ultrasound:

Ultrasound features: Left breast, lower outer quadrant at 4 o’clock

‣ Mass
• Location:	Left breast, lower outer quadrant at 4 o’clock
• Number:	Ultrasound transverse scan left breast shows multiple dilated ducts with intraductal lesions along the walls of the ducts
• Size:	Largest 0.4 cm in greatest dimension
• Shape:	Irregular
• Orientation:	Not parallel
• Margins:	Indistinct
• Echo pattern:	Hypoechoic
• Posterior features:	No posterior features
‣ Calcifications:	None
‣ Associated features:	Duct changes: ectatic duct with intraductal lesion along the walls
‣ Special cases:	None

BI-RADS:

BI-RADS Category: 4B (moderate suspicion of malignancy)

Further assessment:

Further assessment advised: Further imaging with breast MRI

MRI:

MRI features:
‣ MRI features:		Amount of fibroglandular tissue: ACR category a (the breasts are almost entirely fatty). Background parenchymal enhancement: Minimal (< 25%), symmetrical

‣ Location:		Left breast, lower quadrant
‣ Focus:		No
‣ Mass:
• Shape:	No
• Margin:	No
• Internal enhancement:	No
• Kinetic curve:	No
‣ Non-mass enhancement:
• Distribution:	Intraductal and periductal non-mass-like enhancement in the inferior half at 5–8 o’clock
• Internal enhancement:	Heterogeneous
‣ Non-enhancing findings:		No
‣ Associated features:		Architectural distortion
‣ Axillary nodes:		No

Cytology:

Cytology features:

‣ Type of sample:	Nipple discharge
‣ Site of biopsy:
• Laterality:	Left
• Quadrant:
• Localization technique:
• Nature of aspirate:	Brownish yellow discharge
‣ Cytological description:	Smear from nipple discharge shows predominantly foamy macrophages and a few haemosiderin-laden macrophages. Occasional clusters of ductal epithelial cells are seen showing nuclear atypia
‣ Reporting category:	Atypical, probably benign
‣ Diagnosis:	Atypical, probably benign. Category 3 of IAC Yokohama System is atypical, probably benign
‣ Comments:	None

Cytology features:

‣ Type of sample:	FNAC
‣ Site of biopsy:
• Laterality:	Left
• Quadrant:	Lower half
• Localization technique:	Palpation
• Nature of aspirate:	whitish
‣ Cytological description:	Smear shows many dyscohesive clusters and scattered solitary plasmacytoid cells with large pleomorphic nuclei and moderate cytoplasm. Background shows presence of RBCs and many macrophages; a few are haemosiderin laden. Many fibroadipose tissue fragments are also seen
‣ Reporting category:	Suspicious, probably in situ or invasive carcinoma
‣ Diagnosis:	Suspicious, probably in situ or invasive carcinoma
‣ Comments:	None

Histopathology:

MRM

Histopathology features:

‣ Specimen type:	MRM
‣ Laterality:	Left
‣ Macroscopy:	On serial sectioning, a firm grey white area (7.8 × 3.0 × 2.5 cm) is seen in the central and lower quadrants. It is 3.0 cm from the skin and 1.5 cm from the base. The remaining breast tissue appears unremarkable
‣ Histological type:	Intraductal papillary carcinoma with invasive carcinoma
‣ Histological grade:	Grade 2 (3 + 2 + 1 = 6)
‣ Mitosis:	3
‣ Maximum invasive tumour size:	0.7 cm in greatest dimension
‣ Lymph node status:	0/15
‣ Peritumoural lymphovascular invasion:	Absent
‣ DCIS/EIC:	DCIS of solid, micropapillary, papillary, and flat-type intermediate grade; EIC present with multiple foci of microinvasion
‣ Margins:	Free of tumour, distance from nearest margin (i.e. base) 0.7 cm
‣ Pathological stage:	pT1N0
‣ Biomarkers:
‣ Comments:	The intraductal papillary carcinoma involves several large ducts, a few of which are cystically dilated with papillary carcinoma within the duct. Multiple foci of microinvasion are seen

Case summary:

Postmenopausal woman presented with left breast blood-stained nipple discharge, diagnosed as multiple dilated ducts with intraductal solid lesions in the left breast, BI-RADS category 4B on imaging, as suspicious, probably in situ or invasive carcinoma, left breast on cytology, and as intraductal papillary carcinoma with invasive carcinoma on histopathology.

Learning points:

Intraductal papillary carcinoma (papillary DCIS) is defined as a malignant non-invasive neoplastic proliferation with papillary architectural features occurring in the lumen of the ductal lobular system. The invasive component in this case was very small compared with the DCIS component.