Case number:	108
Age:	52
Clinical presentation:	Premenopausal woman presented for mammography screening. She had an increased risk of breast cancer because of family history, and was scheduled for mammographic surveillance.

Mammography:

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

‣ Location of the lesion:	Right breast, upper outer quadrant at 10 o’clock, middle third
‣ Mass:
• Number:	1
• Size:	0.7 cm in greatest dimension
• Shape:	Irregular
• Margins:	Indistinct
• Density:	Equal
‣ Calcifications:
• Typically benign:	None
• Suspicious:	None
• Distribution:	None
‣ Architectural distortion:	None
‣ Asymmetry:	None
‣ Intramammary node:	None
‣ Skin lesion:	None
‣ Solitary dilated duct:	None
‣ Associated features:	None

Ultrasound:

Ultrasound features: Right breast, upper outer quadrant at 10 o’clock

‣ Mass
• Location:	Right breast, upper outer quadrant at 10 o’clock
• Number:	1
• Size:	0.7 cm in greatest dimension
• Shape:	Irregular
• Orientation:	Not parallel
• Margins:	Spiculated
• Echo pattern:	Hypoechoic
• Posterior features:	Posterior shadowing
‣ Calcifications:	None
‣ Associated features:	None
‣ Special cases:	None

BI-RADS:

BI-RADS Category: 5 (highly suggestive of malignancy)

Further assessment:

Further assessment advised: Further imaging with breast MRI

MRI:

MRI features:
‣ MRI features:		Amount of fibroglandular tissue: category b (there are scattered areas of fibroglandular density). Background parenchymal enhancement: Mild (25–50%), symmetrical

‣ Location:		Right breast, upper outer quadrant
‣ Focus:		No
‣ Mass:
• Shape:	Round
• Margin:	Spiculated
• Internal enhancement:	Intense homogeneous
• Kinetic curve:	Type 3
‣ Non-mass enhancement:
• Distribution:	No
• Internal enhancement:	No
‣ Non-enhancing findings:		No
‣ Associated features:		No
‣ Axillary nodes:		No

Cytology:

Cytology features:

‣ Type of sample:	FNAC
‣ Site of biopsy:
• Laterality:	Right
• Quadrant:	Upper outer
• Localization technique:	Palpation
• Nature of aspirate:	Whitish
‣ Cytological description:	Smears reveal many sheets of tightly cohesive, benign ductal epithelial cells and bare nuclei. A few sheets of ductal epithelial cells show anisonucleosis, enlarged, mildly hyperchromatic nuclei and moderate amounts of cytoplasm
‣ Reporting category:	Suspicious, probably in situ or invasive carcinoma
‣ Diagnosis:	Predominantly benign cells with a few cells suspicious for malignancy
‣ Comments:	None

Histopathology:

Breast-conserving surgery

Histopathology features:

‣ Specimen type:	Breast-conserving surgery
‣ Laterality:	Right
‣ Macroscopy:	On serial sectioning, a small firm greyish white area (0.6 × 0.5 × 0.5 cm) is seen. The closest cut margin is the superior margin, which is 1.5 cm from the tumour
‣ Histological type:	Invasive carcinoma of no special type, a few with tubular carcinoma morphology
‣ Histological grade:	Grade 1 (2 + 1 + 1 = 4)
‣ Mitosis:	3
‣ Maximum invasive tumour size:	0.6 cm in greatest dimension
‣ Lymph node status:	0/14
‣ Peritumoural lymphovascular invasion:	Not identified
‣ DCIS/EIC:	Small foci of cribriform type – low grade
‣ Margins:	Free of tumour
‣ Pathological stage:	pT1N0
‣ Biomarkers:
‣ Comments:	Amount of fibroglandular tissue: category b (scattered fibroglandular tissue). Background: parenchymal enhancement: Mild (25–50%), symmetrical.

Case summary:

Premenopausal woman with increased risk of developing breast cancer presented for screening. Mammography, breast ultrasound, and breast MRI reveal right breast irregular subcentimeter-size lesion of suspicious morphology, diagnosed as BI-RADS category 4C on imaging, suspicious for malignancy on cytology, and invasive breast carcinoma of no special type, pT1N0 on histopathology.

Learning points:

Screen-detected suspicious findings were further evaluated on supplementary ultrasound and MRI in view of the patient’s high-risk family status. Tissue sampling confirmed the presence of malignancy.