Nephrology Lecture #4

What is distention of the ureter known as?

Hydroureter

What is hydronephrosis?

Distention of renal calyces and pelvis with urine, usually due to obstruction of urine outflow.

What is the term for distention of the ureter and kidney?

Hydroureteronephrosis

Who is hydronephrosis more common in men or women ages 20-60?

Women

True/False: Hydronephrosis is more common in men over 60.

True

What would you see on a BMP for hydronephrosis?

Bilateral obstruction or unilateral obstruction in the presence of underlying kidney disease which will lead to an increase in creatinine.

What is the preferred imaging test for hydronephrosis?

Renal US

A 69-year-old man with a history of benign prostatic hyperplasia (BPH) presents to the emergency department with decreased urine output, fatigue, and bilateral lower abdominal discomfort for the past 2 days. He denies fever, dysuria, or flank pain. Physical exam reveals a distended bladder and mild suprapubic tenderness. Labs show:

Creatinine: 3.2 mg/dL (baseline 1.2)

BUN: 55 mg/dL

Urinalysis: Normal

Electrolytes: Mild hyperkalemia

Bladder scan: >600 mL post-void residual

What explains this patient's acute kidney injury?

What is the preferred imaging test for this condition and what would you find?

What procedure can you use to visualize the inside of the bladder?

How do you treat this?

1.) Post-renal obstruction from BPH. This is a classic example of Hydronephrosis (backed up urine causing swelling)

2.) Renal US is preferred initial test and you would find hypoechoic fluid that displaces the echogenic sinus fat.

3.) Cystoscopy

4.) Treatment based on cause.

For this patient use TURP or other treatment for enlarged prostate

What is a renal scan? What does it show you?

Its a nuclear medicine test that evaluates function and looks for evidence of obstruction.

___________ are epithelium-lined cavities filled with fluid or semisolid material

Renal cysts

Where are simple or solitary cysts typically found?

Found at the outer cortex; fluid filled

How are renal cysts often found?

Incidentally on CT or ultrasound

A 65-year-old man undergoes an abdominal ultrasound for evaluation of vague left flank discomfort. He has a history of well-controlled hypertension and no known kidney disease. The ultrasound reveals a single, round, anechoic lesion measuring 2.5 cm located at the outer cortex of the left kidney. The lesion has sharply demarcated borders, no septations, and no internal echoes. He denies fever, weight loss, hematuria, or urinary symptoms. Serum creatinine is normal.

What is the most appropriate next step in management?

Reassure the patient and observed with routine follow-up

What are the three ultrasound criteria for diagnosing a simple (benign) renal cyst?

1.) Echo-free (anechoic)

2.) Sharply demarcated with smooth walls

3.) Enhanced back wall (indicates good sound transmission

True/False: Majority of renal cysts need to be removed.

FALSE!!! Most do not need intervention unless cyst becomes infected or enlarged and causes symptoms

What is the most common form of PCKD?

Autosomal dominant polycystic kidney disease

Mutations on chromosome 16 ADPKD1 or chromosome 4 ADPKD2

ADPKD

A 42-year-old man presents to your clinic complaining of abdominal discomfort and a feeling of fullness even after eating small meals. He also reports intermittent flank pain and gross hematuria over the past few months. On physical exam, you palpate bilaterally enlarged kidneys. His blood pressure is 152/96 mmHg. He has a family history of kidney disease in his mother, who required dialysis in her 50s.

Laboratory testing reveals:

Serum creatinine: 1.9 mg/dL (elevated)

Urinalysis: microscopic hematuria, mild proteinuria

CT abdomen: multiple bilateral renal cysts

What is most likely the diagnosis?

How do you treat this?

1.) ADPKD

2.)

Antihypertensives

---> ACEi or ARBs are first line

Antibiotics (fx or TMP-SMX) if cysts are infected.

Increased fluid intake if nephrolithiasis

Sodium, caffeine, protein restriction

Cerebral "berry" aneurysms

ADPKD- Extra renal manifestations

Combination of hypertension and large palpable kidneys is suggestive of this disease.

ADPKD

Swiss cheese appearance of cut open kidney (sponge)

Medullary sponge kidney

Solve the riddle.

I am an autosomal dominated mutation you are born with me but I am not typically found until 3rd or 4th decade. I am an autosomal dominant mutation. I can have mutations MCKD1 on chromosome 1 or MCKD2 on chromosome 16. Despite this, I maintain kidney function well and don't cause harm.

What am I?

Medullary sponge kidney

What is the most common clinical presentation of medullary sponge kidney?

Nephrolithiasis.

So most patients diagnosed with medullary sponge kidney are identified only because they develop stones.

What would you find on x ray of medullary sponge kidney?

1.) Grapelike calcifications

What would you find on a CT urogram of MSK?

Striations of papillae

What would you see on CT of MSK?

Papillary calcifications

What would you see on ultrasound of hypoechoic medullary areas, microscopic dilations of papillae, and multiple papillae calcifications?

Medullary sponge kidney

A 28-year-old woman presents with a history of recurrent urinary tract infections and intermittent flank pain. She also reports passing a kidney stone a year ago. She is otherwise healthy, with no history of hypertension or chronic kidney disease. A recent urinalysis reveals microscopic hematuria, and a non-contrast CT scan of the abdomen shows bilateral nephrocalcinosis with calcium-based stones. Her labs are notable for hypercalciuria, but her serum calcium and renal function are normal.

She asks if this condition will get worse or damage her kidneys long term.

What is most likely the diagnosis?

How do you treat this?

Complications can arise from recurrent UTIs but medullary sponge kidney has a good prognosis.

Treatment is supportive care.

This patient may need prophylactic care for recurrent UTIs

What type of genetic disorder is juvenile nephronophthisis?

Autosomal recessive disorder

What is the most common cause of ESRD in younger patients?

Juvenile nephronophthisis

What is juvenile nephronophthisis?

An autosomal recessive inherited kidney disorder that reduces renal concentration ability and presents with small cysts. Usually progresses to ESRD.

A 10-year-old boy is brought to the pediatric clinic by his parents due to concerns about bedwetting, fatigue, and poor growth. They note he drinks water constantly and urinates frequently, including during the night. On physical exam, he appears pale and his height is below the 5th percentile for his age. His blood pressure is normal, but labs reveal:

Mild anemia

Elevated BUN and creatinine

Urinalysis is bland (no proteinuria or hematuria)

Renal ultrasound shows small echogenic kidneys without hydronephrosis

The child requires high salt and water intake to prevent dehydration.

What is likely the diagnosis?

What would a kidney biopsy show you?

What would a CT or US show you?

How do you diagnose this?

How do you treat it?

1.) Juvenile nephronophthisis

2.) Kidney biopsy demonstrates chronic tubulointerstitial changes with thickened tubular basement membranes

3.) Scans show kidney scarring and small kidneys.

4.) Diagnosis is based on clinical findings and positive genetic test

5.) No medical therapy treatment. Once ESKD - Kidney transplant

What is the most common type of fusion anomaly?

Horseshoe kidney

Two distinct kidneys on each side of midline that migrated abnormally and fused

Horseshoe kidney

A 7-year-old boy is brought to the pediatrician for evaluation of recurrent urinary tract infections. His parents report occasional abdominal pain and frequent urination, but no history of fever or vomiting. Growth parameters are within normal limits. A renal ultrasound performed during the evaluation shows fusion of the lower poles of both kidneys, located lower in the abdomen than expected. Moderate hydronephrosis is noted on the right side.

Further imaging suggests ureteropelvic junction (UPJ) obstruction due to abnormal positioning of the kidneys.

Which of the following best explains this patient's condition?

A. Ectopic ureter insertion

B. Vesicoureteral reflux due to posterior urethral valves

C. Horseshoe kidney with ureteral compression

D. Autosomal dominant polycystic kidney disease

How do you treat this?

C. Horseshoe kidney with ureteral compression

1.) Address underlying abnormalities and complications

How do you diagnose horseshoe kidney?

CT urogram - determine anatomy and relative kidney function

Renal US - screen for presence of stones, masses, or hydronephrosis

What is the most common kidney cancer in adults?

Renal cell carcinoma

Where in the kidney does RCC originate?

In the renal cortex

Clear cell

Renal cell carcinoma

Classic triad for renal cell carcinoma.

1.) Hematuria

2.) Flank Pain

3.) Palpable abdominal mass

A 65-year-old man presents to the clinic with fatigue, weight loss, and intermittent gross hematuria for the past month. He reports dull flank pain and recently noticed a new bulge in his left scrotum. He has a 40 pack-year smoking history. On exam, you note a non-tender left-sided abdominal mass and a left-sided varicocele that does not decompress when lying supine.

A CT scan of the abdomen reveals a solid mass in the upper pole of the left kidney with evidence of invasion into the left renal vein.

Which of the following is the most likely diagnosis?

A. Transitional cell carcinoma

B. Renal cell carcinoma

C. Bladder cancer

D. Wilms tumor

Anemia and fever are very common in which type of cancer?

Renal Cell Carcinoma

You find a solid mass on a kidney, what do you always assume until proven otherwise?

Its always RCC until proven otherwise.

What is the first test when evaluating RCC?

CT scan

Your patient has a 3 cm mass on kidney that is renal cell carcinoma. What do you do?

Percutaneous ablation

What is Wilms tumor?

Most common pediatric renal cancer. Its also known as a nephroblastoma that is a painless mass first felt on the abdomen.

What is the most common pediatric renal cancer?

Wilms Tumor

What is wilms tumor typically surrounded by?

Pseudocapsule

What is a pseudocapsule?

Imaging appearance of a capsule around a mass when no true tumor capsule is present at histological evaluation.

Why should kidney biopsy be avoided in Wilms tumor?

Because cancer can spread.

Solve the riddle.

I cause abdominal pain. You can feel me, I am a firm nontender, smooth mass that rarely crosses the midline. I also cause hypertension. What am I?

Wilms Tumor

A 4-year-old girl is brought to the pediatrician by her parents who noticed progressive abdominal enlargement over the past few weeks. The child has no pain or changes in appetite. On physical exam, a firm, smooth, non-tender mass is palpated in the right flank, which does not cross the midline. Her blood pressure is elevated at 130/85 mmHg. Chest auscultation is clear. Urinalysis reveals microscopic hematuria. A renal ultrasound confirms a solid mass in the right kidney.

What is the diagnosis?

What scan do you order for staging?

How do you treat it?

1.) wilms tumor

2.) Chest CT for staging workup

3.) Surgical resection of tumor with possible lymph node dissection

What should you do in bilateral wilms tumor?

High dose chemo

Renal biopsy

Partial nephrectomies in some cases

At what stage of Wilms tumor do you initiate chemo or radiation therapy?

Stage III

What is plasma cell myeloma?

Malignancy of plasma cells characterized by the abnormal secretion of monoclonal paraproteins

What are the two major causes of kidney impairment?

1.) Light chain cast nephropathy

2.) Hypercalcemia

Monoclonal immunoglobulins in serum or urine electrophoresis (IgG is most common)

Plasma cell myeloma

Multiple Myeloma clinical presentation

C - calcium

R - Renal failure

A- Anemia

B - Bone lesions

A 68-year-old man presents with progressive back pain and generalized fatigue for several months. He also reports recent episodes of constipation, increased thirst, and difficulty urinating. Physical examination reveals mild pallor and tenderness over the lower thoracic spine. Labs reveal:

Hemoglobin: 9.5 g/dL

Calcium: 11.6 mg/dL

Creatinine: 2.1 mg/dL (baseline 1.0)

Serum protein electrophoresis (SPEP): M-spike

What imaging should you order?

What is the treatment?

1.) Bone x ray to evaluate for lytic lesions

2.) This patient has plasma cell myeloma. In patients with oliguric or anuria kidney disesae due to high free light chain levels should undergo aggressive chemo

Bone marrow aspiration and biopsy showing monoclonal plasma cells.

Plasma cell myeloma

What is a rare cause of nephrotic syndrome?

Renal amyloidosis

What is the most common type of amyloidosis?

Primary (AL amyloidosis)

What is renal amyloidosis?

Tissue deposit of amyloid

What is primary amyloidosis?

Due to plasma cell dyscrasia which leads to overproduction of monoclonal Ig light chains

What is secondary amyloidosis?

Rare can occur in inflammatory disease, deposition of an acute phase reactant protein

(AA Amyloidosis)

A 68-year-old man presents with progressive swelling in his legs, fatigue, and unintentional weight loss over several months. He has a history of rheumatoid arthritis and chronic joint pain. On exam, he has bilateral pitting edema and low blood pressure. Lab findings include:

Urinalysis: 4+ protein, no hematuria

Serum albumin: 2.0 g/dL

Cholesterol: 310 mg/dL

Creatinine: 2.4 mg/dL

Serum and urine protein electrophoresis: no monoclonal spike

Renal biopsy: deposits that stain Congo red positive with apple-green birefringence under polarized light

What is the most likely diagnosis?

How do you treat it?

1.) Renal amyloidosis

2.) Medical thearpy to eliminate monoclonal protein and the plasma cell clone which may lead to reversal of organ damage.