A case of testicular tuberculosis mimicking malignancy in a healthy young man

Abstract

Genitourinary tuberculosis represents a form of extra-pulmonary tuberculosis that occurs in the kidneys, ureters, seminal vesicles, prostate, testis, vas deferens, and epididymis. Isolated testicular involvement is unusual, and differential diagnosis includes testicular tumor, acute infection, infarction, and granulomatous infection. We report a case of a 36-year-old Ecuadorian man residing in New York, New York, who presented with a painful scrotal mass, weight loss, and purulent discharge from ulcerated lesion in scrotal area 10 years following his immigration to the United States. No other systemic symptoms were noted. Positive QuantiFERON-TB Gold and radio imaging results led to the diagnosis. After extensive workup, acid fast bacilli positive cultures obtained by computed tomography guided fine needle aspiration grew Mycobacterium tuberculosis complex. Anti-tuberculosis chemotherapy was initiated after sensitivity tests were confirmed. Significant recovery after 3 months of directly observed therapy was accomplished.

Introduction

Although tuberculosis (TB) is a curable disease, it continues to be one of the top infectious killers in the world [World Health Organization (WHO), 2015]. In 2014, approximately 9.6 million people became infected with TB and 1.5 million deaths were reported worldwide [Centers for Disease Control and Prevention (CDC), 2016a; WHO, 2015]. Previous reports found that about one third of the world’s population is infected with TB [CDC, 2016a]. TB is caused by Mycobacterium tuberculosis, a tiny, aerobic, non-motile, and airborne bacterium [CDC, 2016a; WHO, 2015; Zajaczkowski, 2011]. Only a very small inoculum of the bacteria is required to cause infection (Zajaczkowski, 2011). TB most commonly affects the lungs; however, involvement of any body system is possible. Extra-pulmonary TB occurs in approximately 10% of the total cases of TB [Frigueiredo & Lucon, 2008; Lamichaney et al. 2014], with most common presentations being lymphatics, pleura, bone/joint, and genitourinary (GUTB). GUTB frequently involves the kidneys and prostate, making the scrotal organs an unusual but possible target site [Figuereido & Lucon, 2008; Kinnear et al. 2016]. We present a case report of a healthy young man with a long-standing left scrotal mass diagnosed as unilateral testicular TB.

Case presentation

A 36-year-old healthy Hispanic construction worker residing in New York City, United States, presented to a family medicine clinic with a 2-year history of left-sided testicular mass and recent history of a purulent discharge from ulcerated lesion in the posterior aspect of the left scrotum. The mass was initially painless; however, it had become moderately painful as it grew in size. The pain was described as dull and localized, with sporadic radiation to the left flank. A history of progressive weight loss of approximately 30 pounds was also reported with no associated symptoms. Although this was the patient’s first visit to our clinic, he did report several visits to other outpatient settings in the New York metropolitan area, where he failed empiric therapy with unknown antimicrobials. The patient was not able to provide additional details regarding any previous evaluation or treatment. Patient had been born in Ecuador and immigrated to the United States one decade ago. He denied any recent travel, previous imprisonment, exposures to TB, or family history of cancer. He admitted smoking a package of cigarettes a day for 5 years. Upon physical examination, he was in apparent distress because of localized testicular discomfort. His vital signs showed a temperature: 98 F, heart rate: 59, respiratory rate: 18, blood pressure: 110/60 mmHg, and weight: 165 pounds (68.4 kg). There were no abnormal findings, except by a tender, edematous, non-erythematous, and non-transilluminable left-sided testicular mass measuring approximately 6 × 6 cm²; accompanied by an ulcerated lesion located in the posterolateral aspect of left scrotal area, which discharged a purulent material.

Initial laboratory workup revealed hemoglobin of 14.8 (13.5–17.5 g/dL), platelets of 269,000 (150–400 × 10³/µL), white blood cells of 10,000 (4.5–11 × 10³/µL), with a differential showing 66% (40–80%) neutrophils, 27.7% lymphocytes (20–40%), 5.3% monocytes (2–10%), 0.5% eosinophils (1–6%), and 0.2% basophils (<1–2%). Erythrocyte sedimentation rate (ESR) of 14 (0–22 mm/h), and angiotensin-converting enzyme (ACE) was 36 (9–67 U/L), alpha-fetoprotein (AFP) was 3.94 (0–9 ng/mL), human chorionic gonadotropin (HCG) < 1 (<1 IU/L), and lactate dehydrogenase (LDH) was 164 (125–220 IU/L). A basic metabolic profile did not show any abnormalities. Human immunodeficiency virus (HIV), Venereal Disease Research Laboratory (VDRL), hepatitis B, hepatitis C, chlamydia, and gonorrhea screening returned negative. However, QuantiFERON-TB Gold test was positive. Swab microscopy culture and sensitivity of the draining ulcerated lesion did not yield any growth. His chest radiograph showed no abnormalities.

A series of three testicular ultrasounds revealed a diffusely heterogeneous left testis with internal vascularity and presence of a complex space occupying lesion along the lateral aspect of the testicle measuring 2.3 × 3 × 2.8 cm³ (Figure 1). These findings suggested a non-conclusive diagnosis of tuberculosis epididymo-orchitis, chronic orchitis, or tumor. Further computed tomography (CT) of the abdomen and pelvis (Figure 2), as well as, magnetic resonance imaging (MRI) with and without contrast (Figure 3) demonstrated a 4 × 2.6 cm² extra-testicular tubular structure along the lateral aspect of the testicle with thick wall enhancement and filled with complex fluid. Consequently, a total of three specimens collected by CT-guided aspiration of the mass were sent for acid fast bacilli (AFB) and fungal cultures. The results yielded Mycobacterium tuberculosis complex, and sensitivity to anti-tuberculosis therapy was confirmed. Because a conservative approach steered and confirmed the diagnosis, left orchiectomy, an initial consideration was unwarranted.

Figure 1.

Color Doppler Ultrasound of right and left testis demonstrates an extra-testicular space occupying lesion along the lateral aspect of left testicle.

Figure 2.

CT scan of pelvis shows an ovoid shaped cystic lesion in the left scrotum with measures of 4×2.6 cm.

Figure 3.

MRI with contrast (coronal view) showing an extra-testicular tubular structure along the lateral aspect of the left testicle with thick wall enhancement and filled with complex tissue.

Antituberculosis chemotherapy was subsequently initiated in accordance with current recommendations. During the first 2 months of treatment, the patient received isoniazid 300 mg daily (with pyridoxine 50 mg daily), rifampin 600 mg daily, pyrazinamide 1500 mg daily, and ethambutol 1600 mg daily. For months 3–6 of treatment, only isoniazid 300 mg daily (with pyridoxine 50 mg daily) and rifampin 600 mg daily were continued. A substantial decrease in pain and size of the testicular mass, as well as cessation of the purulent discharge from the ulcerated lesion, and an overall weight gain of 11 pounds was appreciated after 3 months of therapy. Family counseling and psychological support were provided to ensure medication compliance.

Discussion

Wildbolz (1937) was the first to introduce the term ‘genitourinary tuberculosis’ [Cho et al. 2013; Zajaczkowski, 2011]. In the past, GUTB was reported to be the most common subtype of extra-pulmonary tuberculosis (EPTB); nevertheless, recently, it has been reported in less than 0.5% of EPTB and in only 1.5% of all patients with pulmonary TB in developed countries [Cho et al. 2013]. The diagnosis of GUTB is often unclear, as it may present as a painless or slightly tender scrotal mass with no associated signs or symptoms [Hadadi et al. 2012; Zajaczkowski, 2011]. Although isolated genital involvement accounts for as much as 28% of patients with GUTB, isolated testicular involvement is unusual [Cho et al. 2013; Hadadi et al. 2012; Lamichaney et al. 2014]. Renal TB is the most common among all types of GUTB followed by epididymis, seminal vesicles, prostate, testes, and vas deferens [Lamichaney et al. 2014; Merchant et al. 2013; Zajaczkowski, 2011].

GUTB is more prevalent in men aged 5–90 years, with a mean age of 40.7 years [Figueiredo & Lucon, 2008; Merchant et al. 2013; Zajaczkowski, 2011]. Since tumors are a common etiology of scrotal mass, it is usually very challenging to differentiate them from testicular TB, in the absence of any other clinical findings [Badmos, 2012; Hadadi et al. 2012]. Other differential diagnosis to consider are acute infection, infarction, and granulomatous infection. Risk factors of GUTB include previous history of TB infection, immunocompromised conditions, immigration or travel to endemic areas, immunosuppressive therapy, and prolonged use of steroids [Hadadi et al. 2012]. Sexual transmission has also been noted in some cases [Zajaczkowski, 2011]. For the patient discussed in this report, his native country of Ecuador has a high incidence rate of TB infections of 54 per 100,000 individuals (compared with 3.1/100,000 in the United States) [WHO, 2015]. Some common associated symptoms are malaise, fever, chills, and weight loss. Symptoms of urinary voiding dysfunction are less common [Hadadi et al. 2012]. Physical examination may reveal signs of infection such as epididymal enlargement and scrotal skin thickening, tender, or non-tender palpable nodule [Hadadi et al. 2012]. Atypical presentation of these cases may lead to inaccurate diagnosis and unnecessary surgical approaches [Badmos, 2012]. For instance, a retrospective study conducted in 29 patients with scrotal TB revealed that only 17.2% of patients were initially suspected of TB. Furthermore, this analysis highlighted a lack of alertness among clinicians regarding appropriate diagnostic methods for GUTB as indicated by 69% of patients who underwent unnecessary surgery to obtain a confirmatory diagnosis [Lee et al. 2007].

A combination of patient history, laboratory and imaging studies as well as other diagnostic tests such as fine needle aspiration (FNA) cytology/biopsy and polymerase chain reaction (PCR) may contribute to the search for an accurate diagnosis [Badmos, 2012; Zajaczkowski, 2011]. The laboratory tests to be considered in the diagnosis workup include a complete blood count (CBC), ESR, serum chemistry, and PCR [Hadadi, 2012; Kim et al. 2013; Lamichaney et al. 2014]. Tuberculin skin test (TST) and TB blood tests such as QuantiFERON-TB Gold are also useful in the diagnosis of tuberculosis. TB blood tests, the gold standard being interferon gamma release assay, are not affected for a previous exposure to BCG vaccination as opposed to TST [CDC, 2016b]. Urine analysis may be positive for sterile pyuria, hematuria, or albuminuria, raising the suspicion for GUTB [Hadadi et al. 2012; Zajaczkowski, 2011].

Once GUTB is diagnosed, antituberculosis chemotherapy is the first line therapy that includes rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE) for an initial 2-month period followed by 4- to 7-month period of isoniazid and rifampin [CDC, 2016c; Hadadi et al. 2012; Lamichaney et al. 2014; Lee et al. 2007; Figueiredo et al. 2008; WHO, 2010]. Directly observed therapy (DOT) and clinical monitoring for up to 10 years after receiving antituberculosis therapy has been recommended. Particular attention should be paid to drugs with weight-based dosing, specifically pyrazinamide and ethambutol, as doses of these medications may need to be adjusted as the patient responds to treatment.

Conclusion

Despite being a rare disease, isolated testicular tuberculosis should be considered as a differential diagnosis in cases presenting with scrotal mass. This would significantly reduce any delays in the establishment of an accurate diagnosis thus enhancing the chances for a prompt management and recovery. A surgical approach should be considered only in cases where the diagnosis is not clearly established or when there is a strong clinical indication. Clinicians should be aware of the diagnostic approach of this rare yet frightening disease.