What is the most appropriate next diagnostic step for a 16-year-old male with a firm, fixed, 6-cm, nontender testicular mass, facial acne, gynecomastia (breast swelling), and striae (stretch marks) over the abdomen?

From the Guidelines

The most appropriate next step in diagnosis for this 16-year-old boy is to measure serum alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (β-hCG) concentrations. The patient's presentation strongly suggests a testicular tumor rather than a traumatic cyst as initially diagnosed. The increasing size and firmness of the testicular mass, combined with systemic symptoms like acne, gynecomastia, abdominal striae, and unexplained weight gain, point toward a hormone-producing testicular tumor. These symptoms are consistent with a germ cell tumor that may be secreting hormones.

Key Points to Consider

• AFP and β-hCG are important tumor markers for testicular germ cell tumors, particularly nonseminomatous types, as indicated by the study 1.
• Elevated levels of these markers can help confirm the diagnosis and provide baseline values for monitoring treatment response.
• The patient's age group is also consistent with the peak incidence of testicular cancer, which commonly affects adolescents and young adults.
• According to the guideline by the American Urological Association 1, serum tumor markers (STM) (alpha-fetoprotein [AFP], human chorionic gonadotropin [hCG], lactate dehydrogenase [LDH]) should be drawn and measured prior to any treatment, including orchiectomy.
• The most recent and highest quality study 1 supports the use of serum tumor markers, including AFP and β-hCG, in the diagnosis of testicular cancer.

Rationale for Choosing AFP and β-hCG

• The other listed tests, such as serum alkaline phosphatase activity, serum CA 125 concentration, serum prostate-specific antigen concentration, and urine homovanillic-vanillylmandelic acid, are not specifically indicated for suspected testicular tumors in this clinical scenario.
• The study 1 also emphasizes the importance of measuring serum concentrations of AFP, LDH, and beta-hCG in the evaluation of a testicular mass.
• Therefore, measuring serum AFP and β-hCG concentrations is the most appropriate next step in diagnosis for this patient, based on the strongest and most recent evidence 1.

From the Research

Diagnostic Approach

The patient presents with a firm, fixed, 6-cm, nontender mass in the right testicle, along with symptoms such as facial acne, swelling of the breasts, stretch marks over the abdomen, and weight gain. These symptoms suggest a possible hormonal imbalance, which can be associated with testicular tumors.

Relevant Markers

• Alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG): These are tumor markers commonly associated with testicular germ cell tumors, particularly non-seminomatous tumors 2, 3, 4, 5.
• AFP is often elevated in yolk sac tumors and some non-seminomatous germ cell tumors, while hCG can be elevated in choriocarcinoma and some seminomas 2, 4.

Diagnostic Value

• The measurement of serum alpha-fetoprotein and beta-hCG concentrations is crucial in the diagnosis and management of testicular tumors, especially non-seminomatous germ cell tumors 3, 6.
• Elevated levels of these markers can indicate the presence of a tumor and help in monitoring the response to treatment 3.

Appropriate Next Step

Given the clinical presentation and the importance of tumor markers in diagnosing and managing testicular tumors, the most appropriate next step in diagnosis would be to measure:

• Serum a-fetoprotein and β-hCG concentrations [C], as these are directly relevant to the suspected condition and can guide further management 2, 3, 4, 5, 6.