Sarcoidosis is a chronic multisystem granulomatous disease of unknown cause. The most commonly affected organs are the hilar lymph nodes (LN) and lungs (about 90% of all cases). The typical morphological finding is multiple non-caseating granulomas formed by fibroblasts, lymphocytes, and macrophages (1). The clinical manifestations of sarcoidosis vary considerably and depend on the affected organ, the number of organs involved, the severity of granulomatous infiltration, and whether fibrosis has developed along with functional impairment. In general, corticosteroids are the first-line treatment for patients requiring therapy. Although corticosteroids can maintain disease control in most sarcoidosis cases requiring long-term maintenance therapy, relapses may still occur. In patients who do not respond to corticosteroids, are corticosteroid-resistant, or cannot tolerate corticosteroid tapering, second-line agents such as antimalarials or immunosuppressants can be used as alternatives (2).

This case report presents a patient initially without urological symptoms who, during follow-up, was diagnosed with bladder sarcoidosis, a rare form of involvement.

A 52-year-old female patient presented to the clinic with complaints of fatigue and cough lasting for three months. A chest X-ray at the referring center revealed bilateral hilar fullness (Fig. 1), prompting referral for further investigation and treatment. The patient had a history of diabetes mellitus, treated with oral antidiabetic medication, and a history of thyroid surgery (thyroidectomy), requiring levothyroxine. No additional illnesses or medications were reported. Her family history was unremarkable. Physical examination showed normal respiratory sounds, with an oxygen saturation of 97% on room air, and other system examinations were within normal limits. Laboratory tests revealed an elevated serum angiotensin-converting enzyme (ACE) level of 93.9 U/L (reference range: 8–52 U/L), while other blood tests, including calcium, were within normal limits.

Thoracic computed tomography (CT) showed bilateral hilar and mediastinal lymph nodes. A convex probe endobronchial ultrasound (CP-EBUS) was performed, revealing multiple conglomerated lymph nodes in the right paratracheal and subcarinal areas, the largest being 25 mm in diameter, with three samples taken from each site. Cytological findings were reported as consistent with non-caseating granulomatous inflammation. The patient was followed up without medication for six years.

In a follow-up thoracic CT, a nodule with irregular borders, 1 cm in diameter, was observed in the medial segment of the right middle lobe, along with secondary pleuroparenchymal changes in the basal segments of both lower lobes. A PET-CT scan showed newly detected lymph nodes with moderate to intense hypermetabolism in supradiaphragmatic and infradiaphragmatic lymph node stations, consistent with granulomatous disease. Splenic hypermetabolism was also observed. Given the elevated serum ACE level (140 U/mL), the patient was started on methylprednisolone 20 mg once daily in 2019.

During tapering, the patient developed dark-colored urine and hematuria, leading to referral to the urology clinic. Cystoscopy revealed raised mucosal lesions (Fig. 2), and biopsy confirmed chronic non-caseating granulomatous inflammation. Corticosteroid treatment was continued. Three months later, follow-up cystoscopy showed partial regression of the lesions. Azathioprine 50 mg/day was added after rheumatology consultation, while methylprednisolone was maintained at 4 mg/day. The patient’s follow-up and treatment are ongoing.

Sarcoidosis is a multisystem inflammatory disease characterized by the formation of non-caseating granulomas. The most common sites of involvement are the lungs and hilar lymph nodes (3). Although many patients remain asymptomatic or require minimal therapy, sarcoidosis can affect almost any organ system. Genitourinary involvement, however, is rare (4).

Bladder sarcoidosis is particularly uncommon and difficult to diagnose, as there are no specific laboratory or radiological markers (5). In the literature, only a limited number of bladder sarcoidosis cases have been reported, often presenting with hematuria or irritative urinary symptoms. Our patient initially had no urological complaints, but later developed hematuria, leading to the diagnosis.

As with other organ involvement, corticosteroids remain the mainstay of treatment. Immunosuppressive agents, such as azathioprine, may be considered in patients with relapsing or refractory disease. Bladder involvement should be carefully monitored, as it can lead to hydronephrosis or, rarely, be associated with metachronous bladder cancers (5).

Due to the lack of diagnostic tools beyond symptoms and histopathology, delayed diagnosis and underreporting of bladder sarcoidosis are possible. Therefore, clinicians should remain vigilant and include genitourinary evaluation in the follow-up of sarcoidosis patients.