How do you treat a patient with a history of clinical stage IIb cN2, mixed germ cell embryonal carcinoma treated with BEP and RPLND five years ago, who now has signet ring cell adenocarcinoma with abdominal carcinomatosis with an unknown primary?  

My experience would suggest that this is a second primary unrelated to his germ cell tumor. I would predict that the i12p will be negative and, if it were available, the MiR371 would be negative. I presume his current AFP and HCG are negative. I have seen this situation once with a young man almost ...

I agree with @Craig R. Nichols. If this represents malignant transformation of teratoma along endodermal elements to adenoCA, it does not matter as it would not benefit from any standard systemic chemotherapy. It might be worthwhile to evaluate for HIPEC therapy if one felt it appropriate. Obviously...

I agree with @Craig R. Nichols that this is a second primary cancer. Increased incidences of second primary cancer in testicular cancer survivors have been well-described in the literature (PMID 8471324, 16174857, 17262080). In majority of those studies, gastric cancer is among the top cancers in th...