Case number:	004
Age:	78
Clinical presentation:	Postmenopausal woman with average risk of developing breast cancer presented with a large lump in the right breast. On examination, she had a large firm right breast lump.

Mammography:

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

‣ Location of the lesion:	Right breast, upper inner quadrant at 12–1 o’clock, middle third
‣ Mass:
• Number:	1
• Size:	3 cm
• Shape:	Oval
• Margins:	Circumscribed
• 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 a (the breasts are almost entirely fatty)
Mammography features:

‣ Location of the lesion:	Left breast, upper outer quadrant at 1 o’clock, middle third
‣ Mass:
• Number:	2
• Size:	Largest 0.5 cm
• Shape:	Round
• Margins:	Circumscribed
• 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, central portion of the breast at 12 o’clock

‣ Mass
• Location:	Right breast, central portion of the breast at 12 o’clock
• Number:	Multiple
• Size:	Largest 3.0 cm
• Shape:	Round
• Orientation:	Parallel
• Margins:	Circumscribed
• Echo pattern:	Anechoic
• Posterior features:	Posterior shadowing
‣ Calcifications:	None
‣ Associated features:	None
‣ Special cases:	Simple cyst

Ultrasound features: Left breast, central portion of the breast at 1 o’clock

‣ Mass
• Location:	Left breast, central portion of the breast at 1 o’clock
• Number:	Multiple
• Size:	Largest 0.5 cm in greatest dimension
• Shape:	Oval
• Orientation:	Parallel
• Margins:	Circumscribed
• Echo pattern:	Anechoic
• Posterior features:	Posterior shadowing
‣ Calcifications:	None
‣ Associated features:	None
‣ Special cases:	Simple cyst

BI-RADS:

BI-RADS Category: 2 (benign)

Further assessment:

Further assessment advised: Referral for cytology

Cytology:

Cytology features:

‣ Type of sample:	FNAC done on four occasions
‣ Site of biopsy:
• Laterality:	Right
• Quadrant:	Upper and central
• Localization technique:	Palpation
• Nature of aspirate:	2–6 mL of yellow fluid aspirated each time
‣ Cytological description:	Smears show tight clusters of benign ductal epithelial cells, some with apocrine metaplasia and many foamy histiocytes on a proteinaceous background
‣ Reporting category:	Benign
‣ Diagnosis:	Proliferative fibrocystic change
‣ Comments:	None

Histopathology:

Lump excision

Histopathology features:

‣ Specimen type:	Lump excision
‣ Laterality:	Right
‣ Macroscopy:	Irregular fibrofatty tissue bit (4.5 × 3.5 × 2.5 cm) with small piece of skin on one side (2.0 × 0.7 cm). Cut surface is yellowish, soft to firm, with a few whitish fibrous areas ranging in size from 0.3 cm to 1.0 cm and small cysts ranging in size from 0.3 cm to 0.5 cm in largest dimension
‣ Histological type:	Many of the ducts are cystically dilated, some lined by flattened epithelium; a few show mild epitheliosis and papillary apocrine hyperplasia
‣ Histological grade:
‣ Mitosis:
‣ Maximum invasive tumour size:
‣ Lymph node status:
‣ Peritumoural lymphovascular invasion:
‣ DCIS/EIC:	Not identified
‣ Margins:
‣ Pathological stage:
‣ Biomarkers:
‣ Comments:	Negative for ADH/DCIS/malignancy

Case summary:

Postmenopausal woman presented with right breast lump. Diagnosed as multiple simple cysts in both breasts, BI-RADS 2 on imaging and as proliferative fibrocystic change on cytology and histopathology.

Learning points:

Cysts in older women:

Peak incidence of breast cysts is in women aged 30–50 years, but they may occasionally be seen in postmenopausal women. Most cysts form in the lobule. As the lobular epithelium atrophies, the acini coalesce and dilated fluid-filled spaces form.
Appearance on mammography is of a round or oval circumscribed lesion with lucent halo.