**Core Concept**
Testicular tumors are a diverse group of neoplasms that can be classified based on their histological features and clinical behavior. The incidence of testicular tumors varies with age, with certain types being more common in specific age groups.

**Why the Correct Answer is Right**
In patients older than 60 years, the most common testicular tumor is lymphoma. This is because lymphoma is a type of cancer that arises from the immune system, and its incidence increases with age. In contrast to germ cell tumors, which are more common in younger men, lymphoma is the primary testicular malignancy in older adults. The pathophysiology of lymphoma involves the clonal expansion of malignant lymphocytes, which can infiltrate the testis and cause tumor formation.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because seminoma is a type of germ cell tumor that is more common in younger men. While it can occur in older adults, it is not the most common testicular tumor in this age group.
* **Option B:** This option is incorrect because embryonal carcinoma is also a type of germ cell tumor that is more common in younger men. It is not typically associated with older adults.
* **Option D:** This option is incorrect because teratoma is a type of germ cell tumor that can occur at any age, but it is not the most common testicular tumor in older adults.

**Clinical Pearl / High-Yield Fact**
In older adults, testicular lymphoma often presents with painless testicular enlargement and may be accompanied by systemic symptoms such as weight loss, fever, and fatigue. A high index of suspicion and prompt evaluation are essential for making an accurate diagnosis and initiating appropriate treatment.

**Correct Answer:** C. Lymphoma.