Case number:	062
Age:	63
Clinical presentation:	Postmenopausal woman with average risk of developing breast cancer presented with a lump in the left breast. On examination, she was found to have a hard 3 cm lump in her left breast. Axillary nodes were not palpable.

Mammography:

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

‣ Location of the lesion:	Left breast, lower quadrants at 6 o’clock, posterior third
‣ Mass:
• Number:	1
• Size:	2.8 × 2.5 cm
• Shape:	Irregular
• Margins:	Indistinct
• 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 quadrants at 6 o’clock

‣ Mass
• Location:	Left breast, lower quadrants at 6 o’clock
• Number:	1
• Size:	2.5 × 1.6 cm
• Shape:	Oval
• Orientation:	Parallel
• Margins:	Spiculated
• Echo pattern:	Heteroechoic
• Posterior features:	No posterior features
‣ Calcifications:	None
‣ Associated features:	Minimal internal vascularity
‣ 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:	Lower at 6 o’clock
• Localization technique:	Palpation, soft feel to the needling
• Nature of aspirate:	Whitish
‣ Cytological description:	Highly cellular smears show poorly cohesive clusters and dispersed malignant cells. These cells are large and pleomorphic with prominent nucleoli. Many lymphocytes are seen in the background
‣ Reporting category:	Malignant
‣ Diagnosis:	Carcinoma – high grade. Medullary carcinoma to be considered in view of the lymphocytes
‣ Comments:	None

Histopathology:

Breast-conserving surgery

Histopathology features:

‣ Specimen type:	Breast-conserving surgery
‣ Laterality:	Left
‣ Macroscopy:	Lumpectomy specimen (7.5 × 6.0 × 3.5 cm) oriented with long suture laterally and short suture superiorly. Skin flap is 7.0 × 2.5 cm. On serial sectioning a firm greyish white tumour (2.5 × 2.1 × 2.5 cm) is identified with an intact cystic cavity (1.6 × 1.2 cm) filled with blood
‣ Histological type:	Invasive breast carcinoma of no special type with medullary pattern
‣ Histological grade:	Grade 3 (3 + 2 + 3 = 8)
‣ Mitosis:	28
‣ Maximum invasive tumour size:	2.5 cm in greatest dimension
‣ Lymph node status:	0/29
‣ Peritumoural lymphovascular invasion:	Present
‣ DCIS/EIC:	Absent
‣ Margins:	Free of tumour
‣ Pathological stage:	pT2N0
‣ Biomarkers:
‣ Comments:

Case summary:

Postmenopausal woman presented with lump in the left breast. Diagnosed as left breast carcinoma, BI-RADS 5 on imaging, as breast carcinoma on cytology, and as invasive breast carcinoma of no specific type with medullary pattern, pT2N0 on histopathology.

Learning points:

Invasive breast cancers of no special type with medullary pattern are well-circumscribed breast cancers with high histological grade, pushing margins, syncytial architecture with no glandular structures, regions of necrosis, and a prominent infiltrate of tumour-infiltrating lymphocytes. They are often negative for hormone receptors (ER and PR) and HER2 (triple negative).