A positive result on a home pregnancy test for a male is a rare and confusing event that requires immediate medical evaluation. While these tests are designed to detect pregnancy, a positive result in a man points to a measurable level of a specific hormone. The presence of this hormone indicates that something within the body is producing it abnormally and requires investigation.
Understanding the Test’s Mechanism
Home pregnancy tests function by detecting human chorionic gonadotropin (HCG). This hormone is naturally produced by the developing placenta in a pregnant person. HCG enters the bloodstream and is excreted in the urine, making it detectable by over-the-counter tests.
The test strip is a lateral flow device containing antibodies engineered to bind to HCG. When urine containing sufficient HCG flows across the strip, this binding causes a visible chemical reaction, resulting in a positive line or symbol. The test reacts to the HCG molecule regardless of its source in the body. For a healthy male, HCG levels are typically undetectable or extremely low, usually less than 5 milli-international units per milliliter (mIU/mL).
The Primary Medical Explanation: Testicular Cancer
The most significant cause of a positive pregnancy test in a male is testicular cancer. Certain types of malignant cells in the testes produce HCG, mimicking the function of placental cells. These tumors release HCG into the bloodstream, which then passes into the urine, triggering a positive test result.
Germ cell tumors, which account for the majority of testicular cancers, are often responsible for HCG production. Non-seminomatous germ cell tumors (NSGCTs), especially those containing choriocarcinoma elements, secrete high levels of HCG. Seminomas, another type of germ cell tumor, can also produce HCG, though usually at lower levels.
HCG functions as a tumor marker in these cases, aiding in diagnosis and monitoring. Associated symptoms may include a painless lump or swelling in either testicle, a feeling of heaviness in the scrotum, or tenderness. Elevated HCG can also stimulate estrogen production, which may lead to the development of breast tissue, known as gynecomastia.
Non-Cancerous Sources of HCG
While cancer is the most serious possibility, other factors can cause elevated HCG levels in males. One potential cause is the use of exogenous HCG, which is sometimes prescribed for medical reasons like hypogonadism or used illicitly. HCG injections stimulate the testes to produce testosterone and maintain testicular size, and this external source will show up on a pregnancy test.
Other types of malignant tumors outside of the testicles can also ectopically secrete HCG, although this is rare. These extra-gonadal tumors can originate in the mediastinum (the area between the lungs), the retroperitoneum, or the pineal gland. Cancers of the liver, lung, pancreas, and stomach have also been documented to produce this hormone.
Finally, a positive result may be due to a technical error or a false positive. Highly sensitive tests can sometimes detect trace amounts of HCG considered within the normal range for a healthy male. Cross-reactivity with other substances or interference from heterophilic antibodies in blood tests can occasionally lead to an inaccurate positive reading.
Immediate Steps and Medical Follow-up
If a male receives a positive result on a home pregnancy test, the immediate step is to consult a physician or urologist promptly. Delaying professional care is not recommended, as the underlying cause requires medical confirmation. The doctor will begin the diagnostic process by ordering a quantitative beta-HCG assay, a blood test to measure the precise level of HCG.
This blood test is more accurate than a urine strip and determines the exact concentration of the hormone. The physician will also conduct a thorough physical examination, including palpation of the testicles to check for lumps or masses. Imaging tests, such as an ultrasound of the testicles, will likely be ordered to visualize internal structures and look for abnormal growths.
Depending on the results of the blood work and ultrasound, the medical professional may also check other tumor markers. These include alpha-fetoprotein (AFP) and lactate dehydrogenase (LDH). If a tumor is suspected or confirmed, further imaging like a CT scan of the chest, abdomen, and pelvis may be necessary to determine the extent of the issue. The overall goal is to identify the source of the HCG and begin appropriate treatment without delay.