Synopsis
Distinguish invasive carcinoma of no special type from invasive lobular carcinoma, integrate morphology with extent and nodal assessment, and plan a concordant multidisciplinary treatment pathway.
- Invasive breast carcinoma has crossed the basement membrane and can enter lymphatic or blood vessels; “no special type” replaces the older default label invasive ductal carcinoma.
- Invasive carcinoma of no special type often forms a stellate mass, whereas lobular carcinoma more often infiltrates in single-file strands because loss of cell cohesion can obscure its true extent.
- Diagnosis needs concordant clinical assessment, age-appropriate bilateral imaging and image-guided core biopsy; record tumour type, grade and ER, PR and HER2 status.
Key red flags
A rapidly enlarging hard mass, skin tethering, peau d’orange, bloody nipple discharge or fixed axillary nodes requires urgent diagnostic breast assessment rather than routine surveillance.
Investigation priorities
Confirm invasion and provide sufficient tissue for type, grade and receptor testing.
Management branches
Core biopsy from a 24 mm lesion confirms grade 2 invasive lobular carcinoma and the patient hopes to conserve the breast.
- Confirm that the core sampled the clinical and imaging target; request ER, PR and HER2 together and review grade and any lymphovascular invasion.
- Perform pretreatment axillary ultrasound and image-guided sampling of any abnormal node, documenting whether nodal disease is proven or only suspected.