Japan: A recent case study published in BMC Nephrology has described the first reported case of sarcoidosis with two unusual complications.
Arata Osanami, Sapporo Medical University School of Medicine, Sapporo, Japan, and colleagues report a case of systemic sarcoidosis with a rare combination of interstitial nephritis with necrotizing vasculitis and urinary retention due to prostate involvement.
"We describe a case of sarcoidosis presenting with interstitial nephritis with small-vessel vasculitis and urinary retention due to prostate involvement, which caused renal acute kidney injury (AKI) and post-renal AKI, respectively," the researchers reported. "Given its pathology and clinical course, this case is clinically valuable."

Sarcoidosis affects multiple organs and exhibits diverse clinical manifestations. It is a systemic inflammatory disease with various clinical presentations that commonly involves the skin, lungs, eyes, lymph nodes, and other organs, including the kidneys.
Tubulointerstitial nephritis is a known feature of renal involvement, but necrotizing vasculitis is rare. Furthermore, prostate involvement in sarcoidosis is unusual, with few cases of prostate-related symptoms having been reported. Dr. Osanami presents an extremely rare case of sarcoidosis with acute kidney injury due to a combination of interstitial nephritis with small-vessel vasculitis and urinary retention caused by prostate involvement.
The case concerns a 66-year-old Japanese man with a history of hyperuricemia and bronchitis who developed sudden urinary retention and fever. He was diagnosed with prostatitis and admitted to the hospital. Three days after onset, he received 500 mg/day levofloxacin and 8 mg/day silodosin; however, there was no improvement in voiding condition, and an indwelling urethral catheter was inserted; however, the prostatitis was refractory.
Computed tomography demonstrated enlarged mediastinal lymph nodes. Analysis of transbronchoscopic lymph node and prostate biopsies showed epithelioid cell granulomas, indicating systemic sarcoidosis. During the clinical course, there was a rapid increase in the serum creatinine level to 2.36 mg/dL without oliguria. A kidney biopsy revealed tubulointerstitial injury with moderate lymphohistiocytic infiltration and small-vessel vasculitis in the interstitium.
There was an immediate improvement in the patient's renal function and urinary retention did not recur following oral administration of 60 mg/day prednisolone.
"To the best of our knowledge, this is the first reported case of systemic sarcoidosis with two rare manifestations: prostate involvement and tubulointerstitial nephritis with necrotizing vasculitis," the researchers wrote. "These complications resulted in different AKIs, post-renal AKI due to prostate involvement and renal AKI caused by granulomatous interstitial nephritis with vasculitis."
"There is a need for further case reports and research studies to elucidate the pathogenesis and optimal management of these rare manifestations in sarcoidosis," they concluded.
Reference:
Osanami, A., Yamashita, T., Sakurada, S. et al. Systemic sarcoidosis presenting as a rare combination of interstitial nephritis with necrotizing vasculitis and urinary retention due to prostate involvement: a case report. BMC Nephrol 24, 370 (2023). https://doi.org/10.1186/s12882-023-03430-9