A 24-year-old patient is described who had a 4-year history of pain in
the right upper arm, with distinct night pain, that responded to sali
cylates. From the findings on conventional radiography, bone scintigra
phy and MRI a multifocal osteoid osteoma was suspected, with one focus
in the cancellous region of the greater tuberosity and a second corti
cal focus at the proximal humeral diaphysis. The resection ''en bloc''
of both tumors and histological examination confirmed the diagnosis.
The patient was painfree after the curative resection of the two osteo
id osteomas, Osteoid osteoma is a frequently found benign bone tumor,
accounting for approximately 11% of cases. In rare cases a multicentri
c occurrence has been described. A possible occurrence of more than on
e osteoid osteoma in a single bone, not verified histologically, has b
een reported only three times in the literature. In patients with scin
tigraphic and radiographic findings of two foci, discrete synchronous
multi focal osteoid osteomas should be suspected.