Breast and Soft Tissue Surgery
Questions test triple assessment, staging and receptor-driven treatment in breast cancer, plus the safe management of soft tissue lumps and skin malignancy. The recurring theme is: do not operate on an undiagnosed mass without a plan.
Assessment of a breast lump
- Triple assessment: clinical examination, imaging and pathology. Ultrasound for women under about 40 and for dense breasts; mammography for older women and for screening.
- BI-RADS grades the imaging from 0 (incomplete) to 5 (highly suspicious); grade 4 and 5 need biopsy.
- Core needle biopsy is preferred to fine needle aspiration for solid lesions because it gives histology and grade; FNA remains useful for cysts and axillary nodes.
- Skin signs: dimpling from ligament of Cooper tethering, peau d'orange from dermal lymphatic obstruction, nipple retraction, eczema of the nipple suggesting Paget disease.
Breast cancer management
- Staging by TNM; grade describes differentiation and is separate from stage.
- Receptor status drives treatment: ER and PR by immunohistochemistry, HER2 by immunohistochemistry with in situ hybridisation when equivocal, Ki-67 for proliferation.
- Sentinel lymph node biopsy uses dual localisation with radioisotope and blue dye; axillary clearance is reserved for three or more involved nodes or a failed sentinel procedure.
- Neoadjuvant chemotherapy for HER2-positive and triple-negative disease, and to downstage large tumours.
- Endocrine therapy for 5–10 years: tamoxifen in premenopausal women, aromatase inhibitors in postmenopausal women.
- BRCA1 and BRCA2 carriers need risk-reducing discussion; BRCA1 is more associated with triple-negative disease.
Soft tissue sarcoma and skin cancer
- Sarcoma: assess size, depth and grade with MRI; core biopsy along the line of a future incision. Treatment is wide excision with a 1–2 cm margin plus radiotherapy. Shelling out a lump is wrong.
- A lipoma is soft, mobile and homogeneous on imaging; a rapidly growing deep mass is sarcoma until proven otherwise.
- Basal cell carcinoma: pearly rolled edge, telangiectasia; rarely metastasises. Squamous cell carcinoma is keratinising and can spread to nodes.
- Melanoma: ABCDE features; Breslow thickness determines margins (1 cm for up to 1 mm, 2 cm for deeper) and sentinel node biopsy is offered above 1 mm.
Worked example
A 55-year-old woman has a 2 cm irregular lump. Ultrasound shows a suspicious mass, and core biopsy shows grade 2 invasive ductal carcinoma that is ER positive and HER2 negative; sentinel node biopsy is negative. Treatment is breast-conserving surgery with radiotherapy and endocrine therapy.
Traps that lose marks
Excising a suspected sarcoma without imaging or planning; using FNA alone to diagnose a solid breast mass; confusing grade with stage; omitting receptor testing.