Background: Growing teratoma syndrome (GTS) is an uncommon clinical finding in patients treated for testicular cancer. It is diagnosed during or after chemotherapy as an expanding tumour mass not responding to the treatment while the serum tumour markers are within the normal range. Pathological evaluation of resected tissue confirms the structures of benign mature teratoma. Case: Authors report a case of metastatic germ cell testicular cancer treated with 2 lines of chemotherapy and everolimus, that had finally been subjected for the resection of voluminous metastatic masses. We give a brief overview of current records concerning clinical management of GTS, and support the major role of surgical treatment in GTS. Results: Patient with metastatic mixed germ cell tumour of testis underwent a radical orchiectomy and completed the 1st line treatment with BEP (bleomycin, etoposide, cisplatin) regimen. Radiographic restaging showed considerable disease progression to the retroperitoneum and supraclavicular lymph nodes. Second-line treatment with VIP (etoposide, ifosfamide, cisplatin) did not reverse the progression and the patient was consulted at our institute. Following the enrolment to the clinical study with everolimus, the patient exhibited continual metastatic growth in contrast to serum markers decrease. GTS was confirmed after resection of enormous retroperitoneal tumour mass, as well as from the specimen obtained from the subsequent supraclavicular and hepatal metastasectomy. The patient attained complete remission and has been closely observed over the last 31 months since the last surgery. Conclusion: GTS is resistant to chemotherapy and radiation and complete surgical resection results in excellent disease control. Clinicians should be aware of this infrequent presentation of testicular tumours, to ensure the timely diagnosis and the appropriate surgical removal without any delay. Despite the great extent and vital vasculature encasement, surgery may be feasible and successful, as we report in our case, consistently with the published data.