睪丸結核菌感染:案例報告

張哲睿¹、黃建榮²、張廷安³、李文凱^4,*

¹臺北市立聯合醫院忠孝院區外科部泌尿科; ²臺北市立聯合醫院仁愛院區外科部泌尿科; ³臺北市立聯合醫院仁愛院區病理科; ^{4, *}臺北市立聯合醫院中興院區外科部泌尿科

Testicular tuberculosis: a case report

Che-Jui Chang¹, Andy C. Huang², Ting-An Chang³, Wen-Kai Lee^{4, *}

¹ Division of Urology, Department of Surgery, Taipei City Hospital, Zhongxiao Branch, Taipei, Taiwan.

² Division of Urology, Department of Surgery, Taipei City Hospital, Renai Branch, Taipei, Taiwan.

³ Department of Pathology, Taipei City Hospital, Renai Branch, Taipei, Taiwan.

⁴ Division of Urology, Department of Surgery, Taipei City Hospital, Zhongxing Branch, Taipei, Taiwan.

Introduction:

Tuberculosis (ΤΒ) is a bacterial infectious disease caused by Mycobacterium tuberculosis complex (MTBC). Although TB primarily affects the lungs, approximately 10%–15% of cases involve extrapulmonary sites. Regarding the genitourinary tract, kidneys are the most frequently affected organs. Isolated testicular involvement remains rare and may mimic malignancies, leading to potential delays or misdiagnoses. In this case report, we present a 65-year-old man with testicular TB, highlighting the clinical presentation, diagnostic workup, and therapeutic approach.

Case presentation:

A 65-year-old Taiwanese man presented to the urology outpatient department with complaints of left scrotal pain and swelling that had persisted for several days. He denied experiencing fever, gross hematuria, dysuria, urgency, increased urinary frequency, flank pain, poor appetite, night sweats, or unexplained weight loss. His medical history was unremarkable for systemic diseases or oncological conditions, and he had no history of smoking or occupational exposure to chemicals or radiation. Additionally, there was no family history of cancer. Physical examination revealed left scrotal swelling with tenderness. Urinalysis showed no evidence of pyuria, hematuria, or bacteriuria. Scrotal sonography demonstrated bilateral testicular heterogeneous cystic lesions with septations. A computed tomography (CT) scan identified a 5.5 × 2.9 × 3.7 cm cystic-like lesion in the left scrotum without obvious contrast enhancement, along with an epididymal cyst (Figure 1). Tumor marker levels were all within normal limits (alpha-fetoprotein [AFP]: 3.94 ng/mL, beta-human chorionic gonadotropin [β-HCG]: <0.2 mIU/mL, and lactate dehydrogenase [LDH]: 233 U/L). With an initial diagnosis of epididymo-orchitis, the patient was treated empirically with levofloxacin and cefixime for two months. Despite antibiotic therapy, his bilateral scrotal swelling and tenderness worsened. Magnetic resonance imaging (MRI) later revealed bilateral testicular masses suggestive of lymphoma, lymphoblastic leukemia, metastasis, seminoma, or germ cell tumors (Figure 2). However, complete blood count and differential counts were within normal ranges, and chest X-ray findings were unremarkable, showing no masses or consolidations in the lungs. A left radical orchiectomy was subsequently performed. Gross pathological examination of the excised tissue revealed a 5.5 × 4.5 × 3.5 cm soft, grayish-tan tumor. Microscopic analysis showed extensive areas of caseous necrosis surrounded by histiocytes, lymphoplasmacytic infiltrates, and Langhans' giant cells. Acid-fast bacilli were detected on special staining, confirming a diagnosis of testicular tuberculosis (Figure 3). The patient was started on a standard quadruple anti-tuberculosis treatment regimen.

Discussion:

TB is a rare manifestation of urogenital tuberculosis (UGTB), accounting for up to 3% of UGTB cases. It predominantly affects middle-aged men, with a mean age of 47 years, but can occur at any age. UGTB typically presents in adults due to the lengthy latency period between initial infection and reactivation. The relationship between TB and immunodeficiency is well established. Additionally, Bacillus Calmette-Guérin (BCG) immunotherapy, used for treating bladder cancer, is a recognized cause of secondary TB infection in the developed world.

The course of the disease was subacute over a period of several weeks or months The most common presenting symptom of testicular TB is scrotal swelling or a palpable mass, often mistaken for malignancy. General symptoms related to TB infection, such as fever, night sweats, and weight loss, can also be present but are not always observed. Due to a lack of clinical awareness, testicular TB is frequently underdiagnosed, leading to delays in treatment and potentially severe complications. Up to 69% of cases undergo unnecessary orchiectomy prior to a confirmed TB diagnosis, primarily due to the high suspicion of testicular cancer.

For diagnosis, scrotal ultrasonography is a critical imaging tool. Typical findings include diffusely enlarged, homogeneous or heterogeneous hypoechoic testicular lesions, or a “miliary” appearance with multiple small hypoechoic nodules. These may be accompanied by signs such as endo-testicular cystic lesions with septations, peripheral calcifications, multiseptated hydroceles, or scrotal wall edema. The epididymis may appear nodular and heterogeneously hypoechoic, particularly at the tail, with or without calcifications. Although pelvic CT has limited utility in diagnosing testicular TB, MRI can provide further insights, revealing enlarged testicular masses with heterogeneous signals, septal formations on T1-weighted images, and areas of central necrosis with high T2 signals.

Definitive diagnosis of TB is achieved through the isolation of MTBC. When isolation is not feasible, histopathological evidence of caseating granulomas with multinucleated giant cells is a reliable alternative, provided other granulomatous diseases like brucellosis and sarcoidosis are excluded. Although fine-needle aspiration biopsy can be used for sampling, orchiectomy is often performed due to the suspicion of malignancy. Surgical interventions, including orchiectomy, are clinically indicated for complications such as abscess formation, pelvicalyceal obstruction, nonfunctioning kidneys, or the need for reconstructive procedures of the urinary tract.

Conclusion:

Testicular TB has a typically subacute clinical course, with scrotal ultrasound and pelvic MRI being the most effective imaging modalities for evaluation. Although isolating MTBC remains the gold standard for diagnosis, histological examination can be sufficient when microbiological confirmation is difficult. Testicular tissue provides the highest diagnostic yield for both microbiological and histopathological assessments. The condition is often underdiagnosed due to insufficient awareness among healthcare professionals, emphasizing the importance of recognizing specific clinical and epidemiological characteristics. Adhering to standard antituberculous treatment protocols, as outlined in established guidelines, is essential for successful management.