The craniocaudal view of the right breast showed a “V” shaped distortion of the posterior margin of the parenchyma ("tent sign"). Although the tumor was palpable, it was the only mammographic sign of malignancy.

The patient underwent a NAC skin-sparing mastectomy and immediate prosthetic breast reconstruction. The tumor was an invasive G2 lobular carcinoma of 5.8 cm in greatest dimension; 12 axillary lymph nodes were metastatic.

The tent sign accounts for a significant number of cancers missed by screening radiologists, for it may be the only mammographic sign of malignancy, and is usually seen only in one projection.