Plasmacytoma of anterior maxilla mimicking periapical cyst.

An unusual case of plasmacytoma mimicking a large periapical cyst in the anterior maxilla is described. Of the involved teeth, 22 was discoloured and had an open, immature apex, a feature strongly suggestive of the lesion being of pulpal origin. The case was treated by a conservative endodontic approach, but failed to show any improvement. Apical surgery comprising complete enucleation of the cystic lesion and extraction of the involved tooth was carried out. The unexpected histopathological finding was a plasmacytoma.