A 30-year-old South Asian male with no specific medical history presented with shortness of breath of insidious onset for two months, with facial puffiness and progressive dysphagia. Physical examination revealed dilated veins over the upper chest, upper arms, and back, with an ejection systolic murmur. Thoracic imaging revealed a large mass occupying the anterior mediastinum, encasing the aorta with mass effect on the esophagus, and causing superior vena cava obstruction. Histopathological and immunohistochemical examination of the mass revealed a seminomatous germ cell tumor. Ultrasonography of the testes was normal except for microlithiasis. The patient was initiated on cisplatin-based chemotherapy and showed symptomatic improvement after two cycles. This case describes an uncommon presentation of primary extragonadal germ cell malignancy with testicular microlithiasis, a premalignant condition linked to gonadal germ cell malignancy. Further studies are needed to determine a correlation, if any, between testicular microlithiasis and extragonadal germ cell malignancy.
Keywords: extragonadal germ cell tumors; germ cell tumours (gct); mediastinal germ cell tumor; mediastinal seminoma; testicular microlithiasis.
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