The most likely diagnosis for the tumor at upper end of tibia is:-

* Giant cell tumor - It is the only tumor to involve the joint. It is seen in 20-40 years of age (after skeletal maturity). It occurs in epiphysis (mainly) and extends into metaphysis, so called as epiphyseal-metaphysis tumor * Unicameral bone cyst -Unilocular cystic bone cavity filled with serosanguinous fluid. X-ray shows fallen leaf sign. It often abuts but does not cross the physis. * Aneurysmal bone cyst -Blood-filled cystic spaces. X-ray shows expansile, lytic cystic lesions and MRI shows fluid-fluid levels within the lesion. * Chondroblastoma - presence of "chicken-wire" calcification is pathognomonic.