Case number:	041
Age:	64
Clinical presentation:	Postmenopausal woman with increased risk of developing breast cancer because of breast carcinoma in her daughter presented for screening for breast cancer. Examination revealed a lump, 1.5 cm in diameter, in the upper outer quadrant of the left breast.

Mammography:

Breast composition:	ACR category c (the breasts are heterogeneously dense, which may obscure small masses)
Mammography features:

‣ Location of the lesion:	Left breast, upper outer quadrant at 2–3 o’clock, posterior third
‣ Mass:
• Number:	1
• Size:	1.8 × 1.6 × 1.4 cm
• Shape:	Irregular
• Margins:	Microlobulated
• 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

Breast composition:	ACR category c (the breasts are heterogeneously dense, which may obscure small masses)
Mammography features:

‣ Location of the lesion:	Bilateral breasts: Right: upper inner quadrant at 1 o'clock, anterior third. Left: upper outer quadrant at 1 o'clock, middle third
‣ Mass:
• Number:	0
• Size:	None
• Shape:	None
• Margins:	None
• Density:	None
‣ Calcifications:
• Typically benign:	Round
• 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: Left breast, outer quadrants at 3 o’clock position

‣ Mass
• Location:	Left breast, outer quadrants at 3 o’clock position
• Number:	1
• Size:	1.1 × 1.0 cm
• 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: Referral for cytology

Cytology:

Cytology features:

‣ Type of sample:	FNAC
‣ Site of biopsy:
• Laterality:	Left
• Quadrant:	Upper outer
• Localization technique:	Palpation
• Nature of aspirate:	whitish
‣ Cytological description:	Smears are very cellular with many dyscohesive clusters of malignant ductal cells. Many single isolated malignant cells are also seen
‣ Reporting category:	Malignant
‣ Diagnosis:	Carcinoma – low grade
‣ Comments:	None

Histopathology:

MRM

Histopathology features:

‣ Specimen type:	MRM
‣ Laterality:	Left
‣ Macroscopy:	Cut surface shows a tumour (2.0 × 1.5 × 1.5 cm) in the lateral quadrant. Tumour is 1.5 cm from the base and 3.5 cm from the skin. Cut surface of tumour is firm to hard in consistency, greyish white with infiltrating margins. Areas of fibrosis are seen in the remaining breast
‣ Histological type:	Invasive cribriform carcinoma
‣ Histological grade:	Grade 1 (1 + 1 + 1 = 3)
‣ Mitosis:	2
‣ Maximum invasive tumour size:	2.0 cm in greatest dimension
‣ Lymph node status:	0/14
‣ Peritumoural lymphovascular invasion:	Present
‣ DCIS/EIC:	Cribriform DCIS of low grade
‣ Margins:	Free of tumour, distance of tumour from the margin is 1.5 cm
‣ Pathological stage:	pT1N0
‣ Biomarkers:	ER positive, PR positive, and HER2/neu negative
‣ Comments:	Surrounding breast shows fibrosis and cyst formation

Case summary:

Postmenopausal woman presented with left breast lump. Diagnosed as left breast carcinoma, BI-RADS 5 on imaging, as breast carcinoma on cytology, and as invasive cribriform carcinoma, pT1N0 on histopathology.

Learning points:

In invasive cribriform carcinoma, the cancer cells invade the stroma (connective tissues of the breast) in nest-like formations between the ducts and lobules. DCIS, generally of cribriform architecture as seen in this case, is seen in 80% of cases.