Ureteritis cystica

Ureteritis cystica or pyeloureteritis cystica is a benign condition of the ureters representing multiple small submucosal cysts. 

Epidemiology

Typically, this condition is seen in diabetics with recurrent urinary tract infections. As such, it is most frequently seen in older patients and is more common in women.

Pathology

Etiology

Ureteritis cystica results from chronic urinary tract irritation due to stones and/or infection. Organisms frequently involved include:

• Escherichia coli (most common)

• Mycobacterium tuberculosis

• Enterococcus

• Proteus spp.

• Schistosomiasis

Microscopic appearance

Histologically there are numerous small submucosal epithelial-lined cysts representing cystic degeneration of metaplastic epithelium or submucosal Brunn cell nests ^1-3. Their walls are transparent macroscopically, and the fluid contained within is mucoproteinaceous. There is often a surrounding infiltrate of lymphocytes ⁴. 

Radiographic features

Whether imaged with conventional intravenous excretory urography or more recently with a CT urogram, the appearance is that of multiple small 2-5 mm smooth-walled rounded lucent filling defects projecting into the lumen, usually of the ureter. Rarely they can be up to 2-3 cm in size ^2,4.

They are most common in the proximal ureter, but can be seen anywhere along the urinary tract: bladder (cystitis cystica) or renal pelvis (pyelitis cystica). The condition occurs bilaterally in up to 50% of cases ⁴. 

Treatment and prognosis

Usually no treatment is required for ureteritis cystica per se, but rather the underlying cause of chronic infection may need treatment, e.g. nephrolithiasis. In such cases, the condition may resolve. Often, when no treatable underlying condition is present, the appearance remains stable over time ⁴. 

There is perhaps an increased incidence of formation of transitional cell carcinoma (TCC) ⁵, although this may relate to the common underlying cause of chronic inflammation rather than the disease itself ^6,8.  

History and etymology 

The first report of a case of ureteritis cystica was by Morgagni in the late 18^th century ⁷. The first to describe it were Richmond and Robb ⁵.

Differential diagnosis

The differential is that of multiple filling defects of the ureter and includes:

• transitional cell carcinoma (TCC)

• vascular indentations

• multiple ureteral stones

• blood clots

• Stevens-Johnson syndrome ⁴

• tuberculous urethritis

  • multifocal or long-segment strictures

  • calcification is commonly seen

• leukoplakia

  • squamous metaplasia of the urothelium

  • more common in bladder​