Editing Urinary Tract Infections (section)

=== Infectious Granulomatous Nephritis ===

==== Xanthogranulomatous pyelonephritis (XGP)[https://www.ncbi.nlm.nih.gov/books/NBK557399/] ====
*Epidemiology
**Rare
**Women are more commonly affected than men
**Diabetics at increased risk
*'''<span style="color:#ff0000">Pathophysiology</span>'''
**'''<span style="color:#ff0000">Pathogenesis of XGP (3):</span>'''
**#'''<span style="color:#ff0000">Nephrolithiasis (usually staghorn) leading to</span>'''
**#'''<span style="color:#ff0000">Chronic obstruction and</span>''' 
**#'''<span style="color:#ff0000">Infection</span>'''
**Severe, chronic renal infection typically results in diffuse renal destruction, non-functioning, and enlarged kidney, associated with obstructive uropathy secondary to nephrolithiasis.
**Begins within the pelvis and calyces and subsequently extends into and destroys renal parenchymal and adjacent tissues
**Most cases are unilateral
**'''<span style="color:#ff0000">Pathogens</span>'''
***'''<span style="color:#ff0000">Proteus is the most common organism involved with XGP</span>'''
***'''<span style="color:#ff0000">E. coli is also common</span>'''
*'''<span style="color:#ff0000">Diagnosis and Evaluation</span>'''
**Labs
***Urinalysis
****Usually shows pus and protein
***Urine culture
****≈10% have mixed cultures
**** ≈1/3rd have no growth, probably because many have recently taken or are taking antibiotics when cultures obtained.
*****The infecting organism may be revealed only by tissue cultures obtained during surgery
** '''<span style="color:#ff0000">Imaging</span>'''
*** '''<span style="color:#ff0000">CT</span>'''
**** <span style="color:#ff0000">'''Findings'''</span>
****#<span style="color:#ff0000">'''Unilateral renal enlargement'''</span>
****#<span style="color:#ff0000">'''Large calculus in the renal pelvis, but without dilatation of renal pelvis'''</span>
****#<span style="color:#ff0000">'''Little or no renal function (e.g. low enhancement on nephrographic phase)'''</span>
****#* 50-80% of patients show the classic triad above
****'''Most useful modality'''
*****'''<span style="color:#ff0000">Often cannot be used to differentiate between XGP and renal cell carcinoma</span>'''
******'''Appears similar to virtually every other inflammatory disease of the kidney, as well as renal cell carcinoma'''
*'''<span style="color:#ff0000">Pathology</span>'''
** '''Accumulation of <span style="color:#ff0000">lipid-laden foamy macrophages (characteristic *often tested on exams)</span>'''
*'''<span style="color:#ff0000">Management</span>'''
** '''Antibiotics'''
*** '''May be necessary to stabilize the patient pre-operatively'''
*** '''Occasionally, long-term antibiotics therapy will eradicate the infection and restore renal function.'''
** '''<span style="color:#ff0000">Nephrectomy</span>'''
*** '''Total nephrectomy (radical or simple)'''
****'''Usually performed because the renal abnormality may be diagnosed preoperatively as a:'''
*****'''Renal tumor, suspicious for cancer, and/or is diffuse'''
*****'''Cause for recurrent infections'''
****Surgical approach
*****A retrospective cohort study of 86 patients undergoing nephrectomy for XGP found that in patients undergoing the midline approach had a longer surgical time (p = 0.03) and took more time after surgery to resume oral intake than those in the undergoing the flank retroperitoneal approach. There were no significant differences in the rates of intraoperative and postoperative complications between groups.[https://www.mdpi.com/2077-0383/11/15/4476]
*****Laparoscopic surgery for XGP patients has relatively high conversion rates to open surgery[https://pubmed.ncbi.nlm.nih.gov/35956092/]
******For a well-trained and experienced surgeon, the laparoscopic approach for XGP treatment is a viable surgical option. However, the open approach is more suitable for inexperienced laparoscopists.[https://pubmed.ncbi.nlm.nih.gov/35956092/]
*** '''If localized XGP is diagnosed preoperatively or at exploration, it is amenable to partial nephrectomy'''

==== Malacoplakia ====
* Means “soft plaque” in Greek
* Pathogenesis
** '''Probably results from abnormal macrophage function in response to a bacterial infection, which is most often E. coli.'''
* '''Diagnosis and Evaluation'''
** '''Should be considered when one or more renal masses are observed, particularly in female patients with recurrent UTIs with E. coli''', altered immune response syndromes, or cystoscopic evidence of malacoplakia or filling defects in the collecting system
** '''Biopsy demonstrates von Hansemann cells and Michaelis-Gutmann bodies which are pathognomonic'''
* '''Management'''
** '''Should be directed at control of the UTIs''', which should stabilize the disease process.
** '''Long-term antibiotics (sulfonamides, rifampin, doxycycline, and TMP) are effective'''

==== Renal echinococcosis ====
* Parasitic infection caused by the larval stage of the tapeworm Echinococcus granulosus.
* Diagnosis and Evaluation
** Symptoms are those of a slowly growing tumor.
** Most patients are asymptomatic or have a flank mass, dull pain, or hematuria'''.'''
** '''Because the cyst is focal, it rarely affects renal function.'''
** '''Rarely, the cyst ruptures into the collecting system, and may be associated severe colic and passage of debris resembling grape skins in the urine (hydatiduria).'''
** '''Excretory urography typically shows a thick-walled cystic mass, occasionally calcified'''
** '''Diagnostic aspiration should not be performed''' because of the danger of rupture and spillage of the highly antigenic cyst contents and risk of fatal anaphylaxis
* '''Management'''
** '''Surgery remains the mainstay of treatment'''