Bularreko minbizi gehienak erraz diagnostika daitezke biopsia edo analisi mikrokopikoaren bitartez. Hala ere, badira laborategiko azterketa bereziak behar dituzten bularreko minbiziak.
Bularren azterketa fisikoak eta mamografiek batzuetan bulto bat kantzerosoa den adieraz dezakete eta beste hainbat kalte antzemateko ere baliagarriak dira. Azterketa hauen emaitzak ez direnean guztiz ziurrak, medikuak fluido edo ehun lagin bat har dezake mikroskopioan aztertzeko. Fluido garbi bat agertuz gero, bultoa
Most types of breast cancer are easy to diagnose by microscopic analysis of a sample—or biopsy—of the affected area of the breast. Also, there are types of breast cancer that require specialized lab exams.
The two most commonly used screening methods, physical examination of the breasts by a healthcare provider and mammography, can offer an approximate likelihood that a lump is cancer, and may also detect some other lesions, such as a simple cyst. When these examinations are inconclusive, a healthcare provider can remove a sample of the fluid in the lump for microscopic analysis (a procedure known as fine needle aspiration, or fine needle aspiration and cytology—FNAC) to help establish the diagnosis. The needle aspiration may be performed in a healthcare provider's office or clinic using local anaesthetic if required.<sup>[''clarification needed'']</sup> A finding of clear fluid makes the lump highly unlikely to be cancerous, but bloody fluid may be sent off for inspection under a microscope for cancerous cells. Together, physical examination of the breasts, mammography, and FNAC can be used to diagnose breast cancer with a good degree of accuracy.
Other options for biopsy include a core biopsy or vacuum-assisted breast biopsy, which are procedures in which a section of the breast lump is removed; or an excisional biopsy, in which the entire lump is removed. Very often the results of physical examination by a healthcare provider, mammography, and additional tests that may be performed in special circumstances (such as imaging by ultrasound or MRI) are sufficient to warrant excisional biopsy as the definitive diagnostic and primary treatment method.