We report two cases of solitary plasmacytoma of the skull, a very unus
ual presentation and location of this tumor. There seems to be no diff
erence in prognosis between the tumor originating from the skull (osse
ous form) and from the dura mater (non-osseous form), differently from
the data of other parts of the body. The risk of secondary multiple m
yeloma appears to be low but the mean follow-up is too short for any c
onclusion on this point.