A rare case of metachronous pituitary germinoma and testicular seminoma: The role of tumor markers in diagnosis and the influence of glucocorticoids on disease progression

Abstract

The presence of both an extragonadal germ cell tumor and gonadal germ cell tumor is a rare occurrence with few cases reported in the literature. We herein report a case of a young man presenting with hypophysitis due to a pituitary germinoma. After a course of high dose glucocorticoid (GC) therapy and the surgical removal of the germinoma, a testicular seminoma was discovered, an apparently second distinct primary germ cell tumor. Hypophysitis was initially attributed to lymphocytic hypophysitis due to the largely unrevealing secondary work up that included beta-human chorionic gonadotropin (b-hCG) and alpha fetoprotein (AFP), which highlights the pitfalls of relying on the tumor marker of b-hCG in both germinomas and seminomas and the important role of biopsy for definitive diagnosis of hypophysitis etiology. Furthermore, the presentation of the seminoma following a course of high dose GC indicates that immunosuppressive therapies may promote the growth of these germ cell tumors.