IgG4-related Kidney Disease Mimicking Malignant Ureter Tumor: Case Report and Literature Review.

Immunoglobulin G4-related disease is a recently recognized systemic disease that can affect any organ or tissue in the body, including the kidneys. IgG4-related kidney disease (IgG4-RKD) is an important part of immunoglobulin G4-related disease. The most common renal manifestation of IgG4-RKD is tubulointerstitial nephritis and glomerular lesions. There, however, is few case of IgG4-RKD mimicking malignant ureter tumor leading to severe hydronephrosis. We herein report an unusual case of IgG4-RKD mimicking malignancy.A 66-year-old Asian man presented to the nephrologist with soreness of loins, anorexia, and acute kidney injury in 2010. His renal function spontaneously improved after 2 weeks' hemodialysis without systemic steroid therapy. Four years later, he presented to the urologist with severe left hydronephrosis because of marked thickness of the left ureter wall. As a ureteral malignancy could not be ruled out, laparoscopic nephroureterectomy was performed.IgG4-related kidney disease was confirmed by the histologic examination. Then, repeat laboratory test showed almost complete recovery of renal function after initiation of steroidal therapy.This case highlights the rare possibility of IgG4-RKD mimicking malignant ureter tumor. Nephrologist and pathologists should be aware of the possibility that hydronephrosis with ureter obstruction may be involved in IgG4-RKD.

Tubulointerstitial Nephritis and Uveitis Syndrome in an Elderly Man: Case Report and Literature Review.

Tubulointerstitial nephritis and uveitis (TINU) syndrome is a rare disease of unknown etiology defined by the combination of tubulointerstitial nephritis, uveitis, and biochemical abnormalities. It has been reported that TINU mainly affects adolescents and young women. Here we reported a special case regarding a 60-year-old man with acute renal failure due to TINU syndrome documented by renal biopsy.We present a rare case of an elderly patient, who had been suffering from a fever for 2 weeks, characterized by sudden onset and resolving spontaneously, and accompanied by extreme fatigue, loss of appetite, and shivering. Renal biopsy showed a tubulointerstitial nephritis, with polymorphonuclear infiltration and acute tubulitis. In the outpatient clinic, he was diagnosed with idiopathic bilateral anterior uveitis 1 month ago. Ophthalmological examination revealed anterior asymptomatic bilateral uveitis. Human leukocyte antigen (HLA) typing (HLA-DQA1*0101/0201 and HLA-DQB1*0303/0503) was found which supported the suspect of TINU syndrome. The patient was treated with oral prednisone (1 mg/kg) and continued for 8 weeks on tapering doses. Serum creatinine normalized within 3 and 6 months later renal function also recovered completely.This case highlights that TINU syndrome is probably an underdiagnosed disease responsible for some cases of idiopathic anterior uveitis in elderly male patients. It is of critical importance to be aware of this syndrome by nephrologist and ophthalmologists in this special population. Further studies are needed to elucidate clinical characteristic and pathogenesis of TINU syndrome in elderly population.