Three days before a woman arrived at a Brooklyn hospital with a firm, tender mass limiting the movement of her right arm, a radiologist had read her mammogram and assigned it BI-RADS 3: probably benign. The biopsy that followed found diffuse large B-cell lymphoma.
That case, published in Cureus, came with a detail that changes how it should be read. The patient had AIDS, and immunosuppression is a recognized driver of aggressive extranodal lymphoma. Her pre-test probability was never that of an average screening patient. What the case still demonstrates is a specific and under-appreciated problem: a small group of breast cancers that are not carcinomas at all, that imaging cannot reliably distinguish from anything else, and that require the opposite treatment from the one a breast surgeon would normally reach for.
