Absent Testis With a Mediastinal Germ Cell Tumor

Primary mediastinal mixed germ cell tumors (PMMGCTs) are rare, aggressive tumors that, at diagnosis, are typically metastatic. A 22-year-old male with a three-month history of cough, chest pain, and fever presented to our outpatient department. Clinical examination showed reduced left-sided air entry in the left hemithorax, with a non-palpable left testis. Imaging suggested a large anterior mediastinal mass and an absent left testis. Multiple biopsies revealed only necrotic tissue, and laboratory investigations showed elevated alpha-fetoprotein levels. A provisional diagnosis of mediastinal germ tumor was made, and surgical excision was planned given absent nodal or distant metastasis. Intraoperatively, a densely adherent bosselated mass was found. A biopsy revealed a mixed germ cell tumor with a predominant seminoma component and chemotherapy with cisplatin and ifosfamide was advised. However, the patient was lost to follow-up after one cycle. PMMGCTs possibly occur due to reverse migration. These tumors warrant an early diagnosis due to their highly aggressive nature. A multimodal approach with chemotherapy with surgical resection is recommended. Our case sheds light on the possible mechanism and emphasizes the impact of early diagnosis.