Late recurrence of a seminoma of the testis with a poorly differentiated neuroendocrine carcinoma component.

The frequency and clinical relevance of late recurrences of testicular germ cells tumors (GCTs) has increased in the past few decades because of the improved survival of patients following the introduction, in the late 1970s, of cisplatin-based chemotherapy. The late recurrences of GCT may take extremely variable features and occur several years after the primary tumor, making the diagnosis a challenge for both clinicians and pathologists. This study reports a case of a testicular seminoma that relapsed 28 years after surgery as an undifferentiated GCT with a heterologous component of neuroendocrine carcinoma that was initially misdiagnosed as a metastasis of primary intestinal tumor.