An Uncommon Presentation of a Metachronous Testicular Primary Nonseminoma and Seminoma Separated by Two Decades and a Testicular Cancer Literature Review

INTRODUCTION Testicular cancer is the most common malignancy in men aged 15-40 years [Bols et al.: Philadelphia, Wolters Kluwer, Lippincott Williams & Wilkins, 2011]. Its incidence comprises 0.8% of all male cancers worldwide, with a mortality rate of 0.1%. The incidence has nearly doubled from 1975 to 2007 leading to the concern of environmental causes [Thomas: Am J Epidemiol 2013; 178: 1240-1245]. Testicular cancer presents as a painless testicular mass without transillumination. Testicular cancer is subcategorized under germ cell testicular cancer or sex cord-stromal tumors. Of the germ cell tumors, approximately 90% originate in the testis, with the other 10% being extragonadal [Bols et al.: Philadelphia, Wolters Kluwer, Lippincott Williams & Wilkins, 2011]. Typically, if a patient presents with a testicular mass and is 50 years old or older, the diagnosis of a primary lymphoma is considered until proven otherwise [Bols et al.: Philadelphia, Wolters Kluwer, Lippincott Williams & Wilkins, 2011]. Germ cell testicular cancer is further divided into the subtypes of seminomatous and nonseminomatous; each presents with a unique histology and differing treatment implications. DISCUSSION Given the uniqueness of our patient's metachronous second testicular primary, we sought to compare our case findings to available historic publications. We sought to address the issues of the incidence of a second primary testicular malignancy with regard to varying histology, age of incidence, and timing of a second primary testicular cancer, the presence of bowel involvement, and finally a brief discussion of testosterone replacement therapy. CONCLUSION A review of our case presents several unique factors. The above varying literature has shown our patient to have met the odds of a contralateral testicular primary development in that he had a nonseminomatous primary, followed by a second testicular primary seminoma. Our patient exceeded the 15-year cumulative risk of contralateral metachronous testicular cancer of 1.9% versus the seemingly contradictory 5.2% cumulative risk 25 years after the first testicular germ cell tumor. With his second primary (seminoma), he presented with the common retroperitoneal landing zone site, though with an uncommon involvement of the gastrointestinal tract (<1%) and rare incidence of involving the duodenum.