Abstract
Well-differentiated osteosarcoma is extremely rare, there is no sex predominance
and the mean age is in the third decade. The tumor has a strong predilection for
the long bones of the extremities, especially the metaphysis but may also occur
in the diaphysis. Radiologically, the lesion shows no distinctive features,
often simulating fibrous dyplasia or desmoplastic fibroma. We report a case of
well-differentiated osteosarcoma involving the rib of a 45-year-old female. This
is a peculiar case of well differentiated osteosarcoma involving an unusual site
and older patient. We also discuss histological differential diagnosis as well
as clinical features of this rare disease.