Epithelioid and Epithelial Neoplasms of Bone

Context.—Epithelioid and epithelial neoplasms seen in bone are rare and include epithelioid variants of vascular lesions, osteoblastoma, osteosarcoma, chordoma, and chondroblastoma as well as adamantinoma and metastatic carcinoma.Objective.—To provide an overview of tumors with epithelioid histology and address the clinical context and diagnostic issues.Data Sources.—Pertinent literature is reviewed with emphasis on recent and controversial issues.Conclusions.—The differential diagnosis in epithelioid/ epithelial lesions of bone is limited. The primary consideration in many cases is distinguishing primary from metastatic lesions.