Clear cell Paget disease with underlying malignancy: A case report and review of literature.

Paget's disease of the breast (PDB) is a rare form of breast cancer, characterized by the existence of Paget cells. It accounts for nearly 1%-3% of all breast cancers. Glycogen-rich clear cell ductal carcinoma in situ (DCIS) of the breast is an infrequent occurrence. The current study reports a rare case of clear cell PDB with clear cell DCIS. A 53-year-old woman presented with a 3-month history of a left nipple lesion. Core needle biopsy confirmed high-grade DCIS without invasion. The patient underwent left mastectomy with sentinel lymph node sampling. Histopathological examination revealed a clear cell PDB of the nipple, associated with extensive high-grade clear cell DCIS. A total of 11 previously reported cases of PDB and related DCIS were identified in the literature. All patients were female with a mean age of 52.91 years (range 34-68). The right breast was involved in 6 cases (54.55%), the left breast in 3 cases (27.27%), both breasts in 1 case (9.09%), and axillary involvement in 1 case (9.09%). The association of PDB with glycogen-rich clear cell change with underlying glycogen-rich clear cell DCIS is extremely rare. The clinical presentation of PDB should prompt evaluation for underlying malignancy, as this may influence diagnosis, management, and prognosis.