Giant seminoma in an undescended testis presenting as an abdominal wall mass

Seminomas in undescended testes may present as abdominal wall tumours. A unilateral testis tumour in a 29 year old man with ipsilateral undescended testis is presented and relevant literature is reviewed. A 29 year old man presenting with a tender left lower abdominal mass was admitted to our clinic and initial diagnostic tests followed by abdominal computerized tomography (CT) and positron emission tomography/computerized tomography (PET/CT) were performed. Abdominal CT clearly demonstrated the tumour location between the lower left abdominal subcutaneous layer and the external oblique fascia. He underwent surgery and the tumour was resected via en-bloc excision. Pathological diagnosis of the resected specimen was consistent with classical seminoma and no distant metastasis was detected with PET/CT. He was referred to oncology clinic after discharge. Tumours of undescended testis can present as an abdominal wall mass and clinicians must be aware of their existence.