Epididymal histoplasmosis – A case report

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Histoplasmosis is a deep fungal infection caused by the dimorphic fungus Histoplasma capsulatum. We report a case of genitourinary histoplasmosis of the epididymis in an immunocompetent individual, which masqueraded as tuberculosis and malignancy.

A 57-year-old male farmer presented with an asymptomatic scrotal swelling of 2 years duration and discharge of pus from nodules on the scrotal skin for the past 2 months [Figure 1]. He had no history of urethral discharge or trauma. He had no history of alcoholism, smoking, other comorbidities, or intake of any immunosuppressive drugs. He had a history of pulmonary tuberculosis 16 years ago, which was treated. Scrotal exploration of the left side was done 2 years back, and a diagnosis of scrotal tuberculosis was made. He was treated again with anti tubercular therapy (ATT) with no response, and subsequently, multiple abscesses discharging pus appeared on the scrotal skin. The patient was evaluated by a urologist, and an orchidectomy was planned with a suspicion of malignancy. There was no history of contact with birds or soil contaminated with bird droppings. He had no other constitutional symptoms such as fatigue, anorexia, cough, or weight loss.

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Figure 1:

Anterior surface of scrotum showing a swelling with four nodules of size 1 × 1 cm to 2 × 2 cm with pus discharge.

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On examination, there was generalized erythema of the scrotal skin with four nodules measuring 1 × 1 cm–2 × 2 cm on the anterior surface of the scrotum with pus discharge [Figure 1]. No grains were seen. There was a firm, non-tender mass measuring 4 × 5 cm on the left side, which was difficult to differentiate from the left testis. The right testis was normal. In view of the testicular swelling and discharging sinuses, a differential diagnosis of scrofuloderma, botryomycosis, actinomycosis, and carcinoma testes was considered. Human immunodeficiency virus antibody and Mantoux test were negative. Gram stain from the pus discharge showed Gram-positive cocci. No fungus was seen in the potassium hydroxide (KOH) smear, and acid-fast bacilli (AFB) staining was negative. Overnight saline-soaked dressings on the lesion did not show any grains. Pus culture for bacteria was sterile. Ultrasonography of the scrotum showed diffuse scrotal wall collection and edema of the left hemiscrotum with a bulky epididymis and an ill-defined collection around it. The left testis was normal. Chest X-ray, ultrasound of the abdomen, and computed tomography (CT) chest were done and were normal. Fungal culture, AFB culture, atypical mycobacterial culture, cartridge-based nucleic acid amplification test (CBNAAT) for Mycobacterium tuberculosis, and aerobic and anaerobic culture were negative. Semen culture and CT abdomen were not done in our case.

Hematoxylin and eosin stain of a biopsy from a nodule over the scrotum showed granulomatous inflammation with Langhans giant cells and ulcerations. Inside histiocytes, there were fungal spores of 2–3 microns in size with a halo [Figure 2]. Gomori Methenamine Silver stain showed 2–3 micron-sized, uninucleate yeast cells with narrow-based budding and a clear space around, with the morphology of Histoplasma capsulatum var. capsulatum [Figure 3]. A diagnosis of genitourinary histoplasmosis of the epididymis was made. The patient was started on tablet itraconazole 200 mg twice daily, and the scrotal swelling reduced in size gradually, and the pus discharge ceased in 3 months [Figure 4]. The patient has now completed 6 months of treatment, and, on repeat ultrasound, the epididymis was normal with mild diffuse scrotal wall edema.

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Figure 2:

A biopsy from a nodule showing granulomatous inflammation with fungal spores of 2-3 micron size with a halo around(red arrow), inside histiocytes. (Hematoxylin and eosin stain, 40×).

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Figure 3:

Uninucleate yeast cells (2-3 micron sized) with narrow based budding and a clear space around (red arrow), with the morphology of Histoplasma capsulatum var. capsulatum. (Gomori methenamine silver stain, 40×).

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Figure 4:

Three months after starting treatment, showin g a significant reduction in the size of scrotal swelling and nodules.

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The causative agent Histoplasma capsulatum is found in soil contaminated with bird and bat droppings.^[1] The literature suggests that genital histoplasmosis usually occurs as a disseminated infection from a primary focus.^[2] Although the patient was previously treated for pulmonary tuberculosis, we speculate that a prior pulmonary histoplasmosis cannot be excluded, as it may mimic tuberculosis and subsequently disseminate. We consider this as the patient did not have any history of trauma, which could possibly have led to primary cutaneous histoplasmosis, and the pulmonary lesions in both are quite similar.^[3,4] Furthermore, pulmonary histoplasmosis can self-heal in an immunocompetent individual without treatment.^[2] Testicular tuberculosis and histoplasmosis present as granulomatous lesions and pose difficulty in diagnosis, as in our case.^[5] Randhawa et al. reported a case where epididymal histoplasmosis masqueraded as tuberculosis.^[6]

Histoplasmosis in the genitourinary system is indicative of disseminated disease and requires systemic antifungal therapy in all cases, with or without surgical excision.^[5] This case highlights the importance of Histoplasma capsulatum infection as a differential diagnosis in tropical or endemic regions and in patients with granulomatous epididymoorchitis who do not improve after treatments for more common causative agents.