Benign Breast Conditions

The specific benign diagnoses reached after a breast symptom has been worked up with the triple test. All of these are diagnoses of concordance — each is only “benign” once clinical, imaging and (where indicated) biopsy findings agree. Any discordance → refer to a breast surgeon.

Breast cyst

• Age 40–50 (rare <30; tend to regress after menopause). ~1 in 1000 risk of cancer.
• Presentation: usually asymptomatic; variable pain/tenderness. A discrete, firm, mobile, occasionally fluctuant mass.
• Investigation: ultrasound ± mammography (age-dependent).
• Management: FNA drainage; send fluid to cytology if bloody or if a lump remains after aspiration → then refer.

Fibroadenoma

• Most common in the 20s (can occur 10–60). The commonest discrete benign lump in young women.
• Examination: firm, smooth, mobile, rounded (“breast mouse”); may double in size over ~12 months.
• Investigation: triple test — ultrasound + core biopsy (+ mammography if >35).
• Management: if imaging and biopsy are reassuring, repeat imaging at 6–12 months until stable. Refer for excision if >3–4 cm, continuing to enlarge, or any biopsy suspicion.

Phyllodes tumour — a rapidly growing, giant fibroadenoma-like tumour; ~75% benign, ~25% malignant with metastatic potential. Treatment is wide local excision with a rim of normal breast tissue. Suspect it in an unusually large or fast-growing “fibroadenoma”.

Fibrocystic change (fibroadenosis)

• Age 30–50, mostly in the ~5 years before menopause.
• Presentation: pre-menstrual pain, tenderness and swelling; lump size fluctuates through the cycle; uni- or bilateral. Nipple discharge (usually green/grey) can occur.
• Examination: nodularity ± a discrete mass, typically upper outer quadrant.
• Investigation: mammography if diffuse lumpiness and >40; triple test if a discrete lump is palpable.
• Management: as for mastalgia — supportive bra, topical NSAIDs, reassurance.

Mammary duct ectasia

• Peri-menopausal. Benign dilatation of the subareolar ducts.
• Presentation: a poorly defined lump near the areolar margin with local inflammation/erythema of that quadrant; toothpaste-like nipple discharge; green–grey discharge. A whole quadrant may be involved.
• Investigation: mammogram is characteristic (dilated ducts).
• Management: conservative, unless the mammogram is suspicious for malignancy.

Intraductal papilloma

• Benign lesion of a single duct; the commonest cause of blood-stained nipple discharge.
• Must be differentiated from intraductal carcinoma.
• Diagnosis: ultrasound + core biopsy of the lesion.
• Management: excision of the affected duct (microdochectomy or wedge resection).

Breast fat necrosis (traumatic fat necrosis)

• Follows trauma or surgery (an initial inflammatory/erythematous response → chronic fibrotic reaction).
• Mimics carcinoma — a hard, irregular lump ± skin dimpling or nipple retraction; mammogram may show a stellate area with calcification.
• Core biopsy distinguishes it from carcinoma — the diagnosis should not be made on clinical/imaging grounds alone.