Genitourinary TB is the second most common form of extrapulmonary TB, after peripheral lymphadenopathy. TB may involve the kidney as part of a generalized disseminated infection, or as localized genitourinary disease. However, less than 50% of patients with renal TB have radiological evidence of pulmonary TB, and active pulmonary disease is present in approximately 5% of such patients (
4). The development of disease depends on the cellular immune response of the host, which determines the outcome of the infection. The healing process results in fibrous tissue, and the deposition of calcium salts can result in a non-functioning kidney, known as tuberculous autonephrectomy. Renal calcifications may occur commonly in TB and require surgical intervention. In the treatment of this complication, the aim is to ensure the protection of the renal tissue as much as possible ( 5).
Tuberculous bacilli reach the kidney via a hematogenous route and settle in periglomerular capillaries, leading to abscess formation. Caseous necrotizing granulomas extend to the renal papilla and collecting systems. All of these inflammatory changes result in fibrosis, calcifications, ureteral and calyceal strictures that cause loss of renal function, and autonephrectomy (
6). In this situation, nephroureterectomy is unavoidable; however, this is a debatable point if the kidney is non-functioning and symptomless. Some authors have proposed nephrectomy in order to prevent reactivation, while others have recommended life-long follow up. With the development of antituberculous drugs, nephrectomy has become less important, but it can still be required in cases of uncontrolled hypertension or uncontrolled pain associated with the kidney. Additionally, at the end-stage of the disease, fistulas can form to adjacent organs, requiring surgical excision of the fistulous tract and nephroureterectomy ( 7). According to the European Association of Urology Guidelines, the indications for nephrectomy include a non-functioning kidney with or without calcifications, extensive disease involving the whole kidney with hypertension and ureteropelvic junction obstruction, and coexisting renal carcinoma ( 5).
A spontaneous renal fistula to adjacent organs is not an uncommon condition, but a spontaneous nephrocutaneous fistula is still rare. The majority of such fistulas present as spontaneous drainage through the lumbar region, and their etiologies include chronic renal calculi, probably the most common cause. There are some cases of spontaneous nephrocutaneous fistula due to chronic renal TB (
Urogenital TB is difficult to diagnose due to the lack of specific symptoms and signs. Irritative lower urinary tract symptoms, hematuria, and pyuria are the most common complaints. Abnormal radiological findings, including pyelocaliceal dilatation, ureteral stricture, hydroureter, parenchymal destruction, autonephrectomy, and calcifications, can be seen in 61.5% of patients. A definite diagnosis cannot be made with these findings, but urogenital TB should be considered in the differential diagnosis (
Great effort has been put into comprehensive vaccination policies throughout the world in order to eradicate TB, and although mankind has not managed eradication, the incidence has been markedly reduced. However, much scientific evidence is currently accumulating with regard to the increased incidence of multi-drug resistant, extensively drug-resistant, and totally drug-resistant TB, and the diagnosis and treatment of TB is becoming a major issue (
10). Physicians should consider TB in the differential diagnosis for any chronic infection, and should do their best to treat accordingly.
In the present case, the patient had leakage from the lumbar region for more than 10 years. Although he had received various antibiotics and medical treatments over a long period, no benefit was seen. This interesting case report of a delayed diagnosis shows us that in cases of a nonfunctioning kidney with a spontaneous nephrocutaneous fistula, we must keep in mind the possibility of associated renal TB, especially in immunocompromised patients or in geographic areas where TB is a common health problem.