Urinary Tract Infections Pathology Study Guide

Urinary Tract Infections Pathology Video

Urinary Tract Infections

Urinary tract infections are infection of the urethra, bladder, or kidney.

Urinary tract infections include:

Cystitis
Sterile pyuria
Urethritis
Pyelonephritis
Chronic pyelonephritis
Nephrolithiasis

Ascending infection is the primary cause of urinary tract infections (UTIs), and females are more likely to develop it than males.

Risk factors for urinary tract infections (UTIs) include:

Urinary stasis
Multiple sexual partners
Urinary catheter use
Congenital abnormalities of the urinary tract

Urinary Tract Infections. Uropathogenic Escherichia coli (UPEC) cells adhered to bladder epithelial cell. Stefan Walkowski - Not altered. CC BY-SA 4.0
Urinary Tract Infections. Urine may contain pus (a condition known as pyuria) as seen from a person with sepsis due to a urinary tract infection. James Heilman, MD - Not altered. CC BY-SA 3.0
Urinary Tract Infections. Multiple bacilli (rod-shaped bacteria, here shown as black and bean-shaped) shown between white blood cells in urinary microscopy. These changes are indicative of a urinary tract infection. Steven Fruitsmaak - Not altered. CC BY-SA 3.0
Pyelonephritis. CD68 immunohistochemical staining of macrophages and giant cells in a case of xanthogranulomatous pyelonephritis. In this case, CT findings had suggested the possibility of renal cell carcinoma, thus it was excised. Nephron - Not altered. CC BY-SA 3.0
Pyelonephritis. Chronic pyelonephritis with reduced kidney size and focal cortical thinning. Measurement of kidney length on the US image is illustrated by ‘+’ and a dashed line.[20] Kristoffer Lindskov Hansen, Michael Bachmann Nielsen and Caroline Ewertsen - (2015). Not altered.CC BY 4.0
Urinary Tract Infections. Bilateral kidney stones can be seen on this KUB radiograph. There are phleboliths in the pelvis, which can be misinterpreted as bladder stones. Bill Rhodes. Not altered. CC BY 2.0
Urinary Tract Infections. White blood cells seen under a microscope from a urine sample. Bobjgalindo. Not altered. CC BY-SA 4.0

Cystitis

Cystitis is bladder infection.

Symptoms of cystitis include:

Fever
Dysuria
Urinary frequency
Urinary urgency
Suprapubic pain

Laboratory results of cystitis include:

Urinalysis-cloudy urine with greater than 10 white blood cells (WBCs) per high power field (HPF)
Dipstick-positive leukocyte esterase (because of pyuria) and nitrites (bacteria converts nitrates into nitrites)
Culture-greater than 100,000 colony-forming units (gold standard)

Etiologies of cystitis include:

E. coli (80% of cases)
Staphylococcus saprophyticus in young, sexually active women (but E. Coli is still very usual in this population)
Klebsiella pneumoniae
Proteus mirabilis
Enterococcus faecalis

Chronic Cystitis. Chronic bladder infection in C3H/HeJ mice is histologically distinct from chronic cystitis in C3H/HeOuJ mice.Representative paraffin-embedded, fixed bladder sections from C3H/HeOuJ mice with chronic cystitis (22 out of 24 mice; panels A, D, & G), C3H/HeJ mice with high bacterial burdens and evidence of bladder inflammation (5 out of 20 mice; panels B, E, & H), and the remaining C3H/HeJ mice that uniformly lacked evidence of bladder inflammation (15 out of 20 mice; panels C, F, & I) were analyzed at 4 wpi; Bars approximate 50 µm in length. A–F, Sections were stained with hematoxylin & eosin and examined by light microscopy; boxes in panels A–C demarcate boundaries of higher magnification images in panels D–F. G–I, Sections were analyzed by indirect immunofluorescence (IF) microscopy, staining for E. coli (green) and uroplakin III (red), with nuclei counterstained with bis-benzimide (blue). “L” denotes bladder lumen; dashed line indicates approximate location of basement membrane; arrowheads point to urothelial surface bacterial colonization in panel E; and the white arrow points to a mature superficial facet cell containing a possible IBC in panel H. Early severe inflammatory responses to uropathogenic E. coli predispose to chronic and recurrent urinary tract infection. Hannan TJ, Mysorekar IU, Hung CS, Isaacson-Schmid ML, Hultgren SJ - PLoS pathogens (2010). Not Altered. CC.
Acute Cystitis. Photograph of bladder biopsy (H-3640/97): This 49-year old lady developed C-4 tetraplegia three years ago. Since then she has been on long-term indwelling urethral catheter drainage. She developed bladder stone. Histology shows severe acute and chronic inflammation with ulceration. The inflammatory infiltrate includes numerous suburothelial lymphoid follicles. There is focal cystitis glandularis. The method of bladder drainage in spinal cord injury patients may influence the histological changes in the mucosa of neuropathic bladder - a hypothesis. Vaidyanathan S, Mansour P, Soni BM, Singh G, Sett P - BMC urology (2002). Not Altered. CC.
Cystitis Cystica. Histology from the transurethral resection of the posterior superior bladder wall lesion. (a) Cyst involving bladder lamina propria and muscularis propria (H and E, ×100). (b) Cyst lining composed of stratified cuboidal epithelium (H and E, ×400). (c) Ductal structure with a muscular wall in continuity with the detrusor muscle (H and E, ×200). (d) Duct lining composed of cuboidal epithelium (H and E, ×600). Urine cytology: Pitfall due to a “remnant” lesion. Chaump M, Giorgadze T, Schreiner AM - CytoJournal(2015). Not altered. CC.
Polypoid Cystitis. Bladder biopsy specimen (H&E stain) showing intensely congested mucosa (below) bearing a polypoid projection of inflamed, benign urothelium (top), warranting a diagnosis of polypoid cystitis.
Interstitial Cystitis. Representative tissue sections from patients in the study (A, B) and control (C, D) groups after negative control (A, C) or Na+/K+-ATPase (NKA) immunostaining (B, D). Magnification: 600 ×. The black double-headed arrow indicates the urothelium. Scale bar = 20 µm. Impaired Na(+)/K(+)-ATPase Function in Patients with Interstitial Cystitis/Painful Bladder Syndrome. Lee JD, Yang WK, Lee MH - Journal of Korean medical science (2016). Not altered. CC.
Cystitis glandularis. (A and B) Typical cystitis glandularis. Urothelium show reactive changes and underlying proliferation of von Brunn’s nests. (C) Intestinal cystitis glandularis. Sections show the presence of goblet cells and a morphological similiarity to colonic mucosa (stain, trypan blue; magnification, ×100). Cystitis glandularis: A controversial premalignant lesion. Yi X, Lu H, Wu Y, Shen Y, Meng Q, Cheng J, Tang Y, Wu F, Ou R, Jiang S, Bai X, Xie K - Oncology letters (2014). Not Altered. CC.

Sterile Pyuria

Pyuria with a negative urine culture and more than 10 WBCs/HPF and leukocyte esterase is referred to as sterile pyuria.

Sterile Pyuria. Pyuria in a person with urosepsis James Heilman, MD - Not altered. CC BY-SA 3.0
Sterile Pyuria. White blood cells seen under a microscope from a urine sample. Bobjgalindo - Not altered CC BY-SA 4.0

Urethritis

Urethritis is typically caused by Neisseria gonorrhoeae or Chlamydia trachomatis.

Dysuria is a common urethritis presenting symptom.

Computed tomography of abdomen and pelvis showing (a) extensive edema and stranding of subcutaneous tissue at the symphysis pubis and bilateral groin areas; bilateral enlargement of inguinal lymph nodes is also noted (two arrows). (b) Edema and fat stranding extending into subcutaneous tissue at anterior lower abdominal wall area (two arrows).Fournier's Gangrene in a Heterosexual Man: A Complication of Neisseria meningitidis Urethritis. Khemees TA, Porshinsky BS, Patel AP, McClung CD - Case reports in urology (2012). Not Altered. CC.

Pyelonephritis

Pyelonephritis is kidney infection.

Pyelonephritis is usually brought on by ascending infection.

Vesicoureteral reflux is a risk factor of pyelonephritis.

Pyelonephritis presents with:

Leukocytosis
Fever
Flank discomfort
White blood cell casts

The most common pathogens that cause pyelonephritis include:

E. Coli (90% of cases)
Klebsiella species
Enterococcus faecalis

Tubule atrophy and interstitial fibrosis as a result of repeated bouts of acute pyelonephritis.

Vesicoureteral reflux is the common cause of pyelonephritis in children.

Obstruction is a common cause of pyelonephritis in adults.

Pyelonephritis. Acute pyelonephritis with increased cortical echogenicity and blurred delineation of the upper pole. Kristoffer Lindskov Hansen, Michael Bachmann Nielsen and Caroline Ewertsen -Not altered. CC BY 4.0
Pyelonephritis. CD68 immunohistochemical staining of macrophages and giant cells in a case of xanthogranulomatous pyelonephritis. In this case, CT findings had suggested the possibility of renal cell carcinoma, thus it was excised. Nephron - Not altered. CC BY-SA 3.0

Chronic Pyelonephritis

Chronic pyelonephritis results in cortical scarring with blunted calyces.

Urinalysis may show waxy casts if a patient has chronic pyelonephritis.

Histology of chronic pyelonephritis may show atrophic tubules with eosinophilic proteinaceous debris that resembles thyroid follicles termed “thyroidization” of the kidney.

Pyelonephritis. Chronic pyelonephritis with reduced kidney size and focal cortical thinning. Measurement of kidney length on the US image is illustrated by ‘+’ and a dashed line.[20] Kristoffer Lindskov Hansen, Michael Bachmann Nielsen and Caroline Ewertsen - (2015). Not altered.CC BY 4.0

Nephrolithiasis

Nephrolithiasis is the formation of a stone from a urine solute.

Risk factors for nephrolithiasis include:

Low urine volume
High solute concentration in the urinary filtrate

Nephrolithiasis presents as:

Colicky pain
Hematuria
Tenderness on one flank

Stone(s) normally passes within a few hours.

If the stone does not pass by itself, medical or surgical intervention may be necessary.

Nephrolithiasis. Renal ultrasonograph of a stone located at the pyeloureteric junction with accompanying hydronephrosis. Kristoffer Lindskov Hansen, Michael Bachmann Nielsen and Caroline Ewertsen - Not altered. CC BY 4.0
Nephrolithiasis. Axial CT scan of abdomen without contrast, showing a 3-mm stone (marked by an arrow) in the left proximal ureter James Heilman, MD - Not altered. CC BY-SA 3.0
Nephrolithiasis. Noxt altered. CC.
Nephrolithiasis. Small crystals formed in the kidney. The most common crystals are made of calcium oxalate and they are generally 4–5 mm. Staghorn kidney stones are considerably larger. 1. Calcium and oxalate come together to make the crystal nucleus. Supersaturation promotes their combination (as does inhibition.) 2. Continued deposition at the renal papillae leads to the growth of the kidney stones. 3. Kidney stones grow and collect debris. In the case where the kidney stones block all routes to the renal papillae, this can cause extreme discomfort and pain. 4. The complete staghorn stone forms and retention occurs. Smaller solids that break off can become trapped in the urinary glands causing discomfort. 5. Displaced stones travel through the ureter. If they cannot be broken down, they must be physically removed by a surgeon. Darksmoke101 - Not altered. CC BY-SA 3.0
Nephrolithiasis. A kidney stone (yellow) composed of calcium oxalate. - Not altered. CC BY-SA 4.0
Nephrolithiasis. Kidney stone Robert R. Wal - Not altered. Public Domain