Scrotal Masses & Testicular Cancer
Transilluminate, ultrasound, and never cut through the scrotum
Approach to a scrotal mass
Examination. Decide whether the mass arises from the testis or lies beside it, whether you can get above it (a mass you cannot get above suggests an inguinal hernia), and whether it transilluminates. Painful, acute swelling raises torsion or epididymitis, which are handled as emergencies; a painless mass follows the pathway below.
Ultrasound first. Scrotal ultrasound with Doppler is the initial test for any scrotal mass. It separates intratesticular from extratesticular and cystic from solid lesions. Extratesticular and cystic masses are almost always benign, whereas a solid intratesticular mass is malignant until proven otherwise.
| Feature | Hydrocele | Spermatocele / epididymal cyst | Varicocele |
|---|---|---|---|
| Location | Surrounds the testis within the tunica vaginalis | Epididymal head, above and behind the testis | Along the spermatic cord, usually left |
| Transilluminates | Yes | Yes | No |
| Key feature | Testis may be impalpable within it | Separate from the testis | "Bag of worms"; decompresses supine |
| Management | Ultrasound to see the testis; hydrocelectomy if bothersome | Reassure; excise only if large or painful | Repair for infertility, pain, or adolescent atrophy |
Hydrocele and spermatocele
Adult hydrocele. Fluid collects between the layers of the tunica vaginalis, producing a smooth, painless swelling that transilluminates and that you can get above. It may be idiopathic or reactive to a tumor, epididymitis, trauma, or torsion, so ultrasound must show a normal testis before the hydrocele is dismissed. A bothersome hydrocele is treated with hydrocelectomy through a scrotal incision; aspiration with sclerotherapy is an option for poor surgical candidates but recurs more often.
A new hydrocele in a young man hides a tumor until ultrasound proves otherwise.
Pediatric hydrocele. A communicating hydrocele connects with the peritoneum through a patent processus vaginalis, so it enlarges with crying or activity and shrinks overnight. Simple (noncommunicating) newborn hydroceles usually resolve by 1–2 years and are observed. A communicating hydrocele, or one that persists beyond 1–2 years, is repaired through an inguinal incision with high ligation of the processus, exactly as for an indirect inguinal hernia.
Spermatocele and epididymal cyst. A painless, transilluminating cyst of the epididymal head, felt separately above and behind the testis. Spermatoceles contain milky, sperm-rich fluid; epididymal cysts contain clear fluid. Reassurance is enough; excision is reserved for large or painful cysts because epididymal injury can impair fertility.
Varicocele
Mechanism. Dilated veins of the pampiniform plexus, present in roughly 15% of men and far more often among infertile men. About 90% are left-sided: the left gonadal vein takes a long course and enters the left renal vein at a right angle, and that renal vein can be compressed between the aorta and the superior mesenteric artery. Venous hypertension warms the testis, impairing spermatogenesis and sometimes causing atrophy, which makes varicocele the most common correctable cause of male infertility.
Findings. A "bag of worms" that enlarges on standing or with Valsalva, decompresses supine, and does not transilluminate. Grade I is palpable only with Valsalva, grade II is palpable while standing, and grade III is visible.
Repair. Microsurgical subinguinal varicocelectomy or percutaneous embolization is offered for a palpable varicocele with infertility and abnormal semen analysis, persistent pain, or testicular atrophy in an adolescent. Varicoceles seen only on ultrasound are not repaired. Exogenous testosterone should not be used, since it suppresses spermatogenesis.
An isolated right-sided, sudden-onset, or nondecompressing varicocele suggests venous obstruction by a renal cell carcinoma or other retroperitoneal mass; the right gonadal vein drains directly into the IVC. Obtain CT of the abdomen.
Testicular germ cell tumors: diagnosis
Presentation. Germ cell tumors are the most common solid cancer in men aged 15–35. The usual complaint is a painless, firm mass or heaviness, sometimes with a reactive hydrocele. About 10% present with pain from intratumoral hemorrhage, and a firm mass that persists after "epididymitis" is treated needs an ultrasound. Some patients first show metastases: back pain from retroperitoneal nodes, cough or hemoptysis from lung spread, or a supraclavicular node.
Risk factors. Cryptorchidism is the classic risk; orchiopexy, ideally by 18 months, improves fertility and allows self-examination but does not eliminate the excess risk. Others include a prior contralateral tumor, a father or brother with the disease, Klinefelter syndrome (especially mediastinal germ cell tumors), and disorders of sex development with Y-chromosome material. The precursor is germ cell neoplasia in situ, and isochromosome 12p is the characteristic genetic change.
- Scrotal ultrasoundSolid, usually hypoechoic intratesticular lesion
- Serum markersAFP, β-hCG, and LDH drawn before surgery
- Sperm bankingOffered before orchiectomy, chemotherapy, or radiation
- Radical inguinal orchiectomyHigh ligation of the spermatic cord; diagnostic and therapeutic
- StagingCT of the abdomen and pelvis plus chest imaging; repeat markers to confirm expected decline
Why inguinal. The testis drains to retroperitoneal nodes near the renal hilum (left testis to para-aortic nodes below the left renal vein, right testis to interaortocaval nodes), whereas scrotal skin drains to inguinal nodes. A trans-scrotal biopsy or orchiectomy risks scrotal seeding and new inguinal spread, raising local recurrence.
Markers after surgery. β-hCG has a half-life of about 1–3 days and AFP about 5–7 days; a plateau or rise after orchiectomy indicates residual disease. β-hCG stimulates Leydig cells and aromatization, causing gynecomastia, and very high levels can produce hyperthyroidism through TSH-receptor cross-reactivity.
Seminoma versus nonseminoma
| Tumor | Markers | Distinguishing features |
|---|---|---|
| Seminoma | AFP never raised; mild β-hCG in a minority | About half of cases, peak 30s–40s; clear "fried-egg" cells; very radio- and chemosensitive |
| Embryonal carcinoma | Variable AFP and β-hCG | Often part of mixed tumors |
| Yolk sac tumor | AFP | Schiller-Duval bodies; most common testicular tumor of infants |
| Choriocarcinoma | Very high β-hCG | Early hematogenous spread to lung and brain |
| Teratoma | Usually normal | Chemoresistant; residual masses must be resected |
Seminoma treatment. Stage I disease is usually managed with surveillance after orchiectomy (cure about 99%); single-dose carboplatin or radiation are alternatives. Nodal disease receives radiation or cisplatin-based chemotherapy.
Nonseminoma treatment. Stage I disease is managed by surveillance, nerve-sparing retroperitoneal lymph node dissection (RPLND), or one cycle of BEP depending on risk features such as lymphovascular invasion. Metastatic disease receives BEP (bleomycin, etoposide, cisplatin) for 3–4 cycles, and residual masses are resected afterward because they may contain teratoma or viable tumor. Unlike seminoma, nonseminoma is not treated with radiation. Cure rates remain high even with metastases.
Toxicities. Bleomycin causes pulmonary fibrosis; cisplatin causes nephrotoxicity, ototoxicity, and neuropathy; RPLND can cause ejaculatory dysfunction unless nerves are spared.
Tumors in older men and other types
Testicular lymphoma. In men over 60 the most common testicular tumor is lymphoma, usually diffuse large B-cell, often bilateral or with other extranodal sites. After orchiectomy for diagnosis, treatment is R-CHOP with CNS prophylaxis and radiation to the contralateral testis.
Sex cord–stromal tumors. Leydig cell tumors secrete androgens or estrogens, causing precocious puberty in boys or gynecomastia in men, with normal germ cell markers; most are benign.