Does Paget Disease of the Breast Present Bilaterally?
No, Paget disease of the breast is almost always unilateral, with bilateral presentation being extraordinarily rare—documented only in isolated case reports rather than any meaningful case series.
Clinical Presentation Pattern
Paget disease typically presents as a unilateral condition affecting the nipple-areolar complex of one breast, characterized by eczema-like changes, scaling, excoriation, bleeding, ulceration, and itching of the nipple 1.
The disease manifests with neoplastic cells in the epidermis of the nipple-areolar complex and is associated with underlying breast cancer (either DCIS or invasive carcinoma) in 80-90% of cases 1, 2.
Evidence for Bilateral Disease
Bilateral Paget disease is exceptionally rare, with only isolated case reports in the medical literature 3, 4.
One case report from 2003 described synchronous bilateral breast cancer where one breast had Paget disease and the contralateral breast had invasive ductal carcinoma—these were two separate primary cancers, not bilateral Paget disease 3.
A 1990 case report documented true bilateral Paget disease in a 74-year-old woman, explicitly noting "the rarity of this clinical entity" 4.
Clinical Implications
When evaluating suspected Paget disease, bilateral diagnostic mammography with or without ultrasound is mandatory as the initial imaging study, but this is to evaluate both breasts for any underlying malignancy, not because bilateral Paget disease is expected 1, 2.
The bilateral imaging recommendation exists because: (1) standard of care requires comprehensive breast evaluation for any breast cancer diagnosis, and (2) the associated underlying cancer may be located away from the nipple-areolar complex 1, 2.