A Case Report of Giant Cell Tumor of the Tendon Sheath after Treatment of Germ Cell Tumor of Testicles in a 7-year-old boy

Germ cell tumors account for 2 to 3% of all cancers in children. These tumors appear in the testicles as painless masses. The primary treatment of these tumors is the removal of testicles and chemotherapy. Giant cell tumor of the tendon sheath (GCTTS) is slow-growing tumor and the primary treatment of this tumor is surgery and both surgery and radiotherapy in invasive type. This report presents the case of a 7-year-old boy who was diagnosed with germ cell tumor at the age of 8 months. He had undergone surgery and chemotherapy and had recovered. At the age of 7, the patient referred with a mass in right heel and after evaluation and surgery, he was diagnosed with Giant cell tumor of the tendon sheath. Surgery was performed and no evidence of recurrence was observed in follow-up evaluation. To the best of our knowledge, this report is the first case of a giant cell tumor of the tendon sheath following the treatment of testicular germ cell tumor.