In a 68-year-old man with two days of left groin pain radiating into the scrotum, a tender palpable mass adjacent to the left testicle, no fever, urinary symptoms, or trauma, and a prior similar episode that resolved spontaneously, how should his laboratory results be interpreted?

Laboratory Interpretation in a 68-Year-Old Man with Palpable Scrotal Mass

Laboratory results in this patient should focus on ruling out infection (complete blood count, urinalysis) and testicular malignancy (serum tumor markers: AFP, β-hCG, and LDH), but labs alone cannot definitively diagnose the cause of his palpable mass—ultrasound with Doppler is the essential diagnostic test that must be performed immediately. 1

Understanding the Clinical Context

This patient's presentation—a palpable mass adjacent to the left testicle with dull, pulling discomfort in a 68-year-old man—raises several diagnostic possibilities:

• Epididymal pathology (epididymitis, spermatocele, epididymal cyst)
• Paratesticular masses (lipoma, leiomyoma, or rarely leiomyosarcoma)
• Testicular tumor (though less common at age 68, still possible)
• Inguinal hernia extending into scrotum
• Varicocele or hydrocele

The history of a similar self-resolving episode two years ago suggests a benign process, but malignancy must be excluded given his age and the presence of a new palpable mass. 2, 3

Laboratory Interpretation Framework

Infection Markers

• Complete Blood Count (CBC): Look for leukocytosis with left shift suggesting acute epididymitis or orchitis
• Urinalysis with culture: Essential to identify urinary tract infection that could cause epididymitis
• C-reactive protein (CRP) or ESR: Elevated in inflammatory/infectious processes

If these are normal (no fever, no pyuria, normal WBC), infection is unlikely and attention shifts to structural/neoplastic causes.

Tumor Markers (Critical in Any Scrotal Mass)

Even without obvious testicular involvement, obtain:

• Alpha-fetoprotein (AFP): Elevated in non-seminomatous germ cell tumors, yolk sac tumors
• Beta-human chorionic gonadotropin (β-hCG): Elevated in choriocarcinoma, embryonal carcinoma, some seminomas
• Lactate dehydrogenase (LDH): Non-specific but elevated in many testicular tumors

Important caveat: Normal tumor markers do NOT exclude testicular cancer. Up to 30% of seminomas and some other testicular tumors present with normal markers. 4, 5, 6 The patient's concern about cancer is legitimate and cannot be dismissed based on labs alone.

Additional Considerations

• Renal function tests: Given his history of kidney stones and to establish baseline before potential contrast imaging
• Coagulation studies: If surgical intervention becomes necessary

The Critical Limitation of Laboratory Testing

Labs provide supportive information but cannot characterize the mass itself. 1 The ACR Appropriateness Criteria are unequivocal: ultrasound with Doppler is the established first-line imaging modality for any palpable scrotal abnormality. 1

Why Ultrasound is Non-Negotiable

The combination of grayscale and color-power Doppler ultrasound can:

• Distinguish intratesticular from extratesticular masses (fundamentally different prognoses)
• Characterize solid versus cystic lesions
• Assess vascularity patterns (hypervascular lesions more concerning for malignancy)
• Identify epididymal pathology, varicoceles, hydroceles, hernias
• Detect testicular tumors that may present atypically 1

Paratesticular sarcomas (like leiomyosarcoma) can present as painless or minimally painful scrotal masses in elderly men and require surgical excision for diagnosis. 2, 3 These cannot be diagnosed by labs.

Clinical Algorithm for This Patient

1. Obtain labs TODAY:

   • CBC with differential
   • Urinalysis with culture
   • AFP, β-hCG, LDH
   • Basic metabolic panel

2. Order scrotal ultrasound with Doppler URGENTLY (within 24-48 hours):

   • This is the definitive diagnostic test
   • Should include spectral Doppler analysis of both testes for comparison 7
   • Must evaluate spermatic cord for masses or "whirlpool sign"

3. Interpret results in combination:

   • Normal labs + benign ultrasound findings (simple epididymal cyst, small hydrocele): Reassurance, follow-up in 4-6 weeks
   • Normal labs + suspicious ultrasound findings (solid mass, abnormal vascularity): Urgent urology referral for possible surgical exploration
   • Elevated tumor markers regardless of ultrasound: Immediate urology/oncology referral
   • Signs of infection on labs: Treat empirically with antibiotics, repeat exam in 2-3 weeks

Critical Pitfalls to Avoid

1. Do not delay imaging waiting for lab results—order both simultaneously
2. Do not assume normal tumor markers exclude malignancy—ultrasound is still mandatory 4, 5
3. Do not dismiss the patient's cancer concern—paratesticular sarcomas and testicular tumors can present with minimal symptoms in older men 2, 3, 6
4. Do not attribute symptoms to "groin strain" without imaging—this delays diagnosis of serious pathology
5. Do not rely on the history of prior self-resolution—this could be a new, unrelated process

Special Consideration for This Patient

His age (68) makes paratesticular sarcoma a consideration that would not be detected by tumor markers but requires ultrasound characterization and likely surgical excision for definitive diagnosis. 2, 3 The "mass adjacent to the left testicle" description fits this possibility.

Bottom line: Labs help stratify risk and guide urgency, but ultrasound with Doppler is the only test that can adequately evaluate his palpable mass and guide definitive management. Both should be obtained without delay. 1