Case number:	063
Age:	39
Clinical presentation:	Premenopausal woman with average risk of developing breast cancer presented with a rapidly growing left breast lump. On examination, she was found to have a large firm to hard lump in her left breast.

Mammography:

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

‣ Location of the lesion:	Left breast, lower outer quadrant at 5 o’clock, anterior, middle, and posterior thirds
‣ Mass:
• Number:	1
• Size:	5.5 × 4.0 cm
• Shape:	Oval
• Margins:	Circumscribed
• Density:	High
‣ 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: Left breast, lower outer quadrant at 5 o’clock

‣ Mass
• Location:	Left breast, lower outer quadrant at 5 o’clock
• Number:	1
• Size:	5.2 × 4.0 cm
• Shape:	Irregular
• Orientation:	Parallel
• Margins:	Indistinct
• Echo pattern:	Heterogeneous with areas of breakdown
• Posterior features:	No posterior features
‣ Calcifications:	None
‣ Associated features:	Internal vascularity in mass. Enlarged lymph nodes (2.0 × 1.3 cm and 2.0 × 0.7 cm) with loss of central fatty hilum
‣ Special cases:	None

BI-RADS:

BI-RADS Category: 4C (high suspicion for malignancy)

Further assessment:

Further assessment advised: Referral for cytology

Cytology:

Cytology features:

‣ Type of sample:	FNAC (solid lesion)
‣ Site of biopsy:
• Laterality:	Left
• Quadrant:	Lower outer
• Localization technique:	Palpation
• Nature of aspirate:	Whitish
‣ Cytological description:	Highly pleomorphic malignant cells seen with lymphocytes in the background
‣ Reporting category:	Malignant
‣ Diagnosis:	Carcinoma – high grade
‣ Comments:	None

Histopathology:

Breast-conserving surgery

Histopathology features:

‣ Specimen type:	Breast-conserving surgery
‣ Laterality:	Left
‣ Macroscopy:	Cut surface shows a large, greyish white, well-circumscribed tumour (5.5 × 5.0 × 4.0 cm) (T3) with a soft central necrotic area
‣ Histological type:	Invasive breast carcinoma of no special type with medullary pattern
‣ Histological grade:	Grade 3 (3 + 2 + 2 = 7)
‣ Mitosis:	15
‣ Maximum invasive tumour size:	5.5 cm in greatest dimension
‣ Lymph node status:	1/24
‣ Peritumoural lymphovascular invasion:	Not identified
‣ DCIS/EIC:	Not identified
‣ Margins:	Free of tumour
‣ Pathological stage:	pT3N1
‣ Biomarkers:
‣ Comments:	Extensive areas of tumour necrosis seen

Case summary:

Premenopausal woman presented with lump in the left breast. Diagnosed as circumscribed high-density mass with perilesional halo, with left axillary enlarged node of altered morphology, BI-RADS 4C on imaging, as breast carcinoma on cytology, and as invasive breast carcinoma of no specific type with medullary pattern, pT3N1 on histopathology.

Learning points:

“Medullary” carcinoma is a subtype of breast carcinoma and is so-called because the tumour is a soft, fleshy mass that resembles the medulla of the brain. The large tumour with extensive necrosis is seen to displace the adjacent breast parenchyma with perilesional halo, thus forming a clear boundary between the tumour and the normal breast tissue.