Solitary adenocarcinoma metastasis mimicking sarcomatous degeneration in Paget's disease.

A rare case of mucinous adenocarcinoma presented as a solitary, metastatic deposit to a region of Paget's disease within the peripheral skeleton. Historical, physical, radiographic, and scintigraphic findings were indistinguishable from those of sarcomatous degeneration arising from pagetoid bone. This case supports the idea that when a painful, osteolytic lesion is discovered within a region of Paget's disease, bone scintigraphy has greater value of disclosing potential multifocal or multicentric disease than for providing etiologic specificity for the principal lesion.