Nephrolithiasis: Clinical Manifestations and Differential Diagnosis with Case

00:01 When patients present with nephrolithiasis, there's two common presentations that you will see.

00:07 Pain, acute renal colic that is unforgettable to the patient and hematuria - blood in the urine.

00:15 Let's talk a little bit more about acute renal colic.

00:18 It is typically described as an abrupt onset of intensifying pain over time due to ureteral colic meaning that there's a stone lodged in the ureter.

00:27 Now if you've ever had a patient that's had a kidney stone, they will say that that is one of the worst pain they've ever had in their life.

00:35 That flank pain can oftentimes migrate anteriorly along the abdomen to the groin and they may have a nausea, emesis, urinary urgency or hematuria in association with that pain.

00:48 Ureteral stones in particular can mimic things like acute cholecystitis depending on where that stone is so they might be having more right upper quadrant pain or back pain.

00:59 It could mimic acute appendicitis if it's more epigastric or more in the lower quadrant on the right Cystitis or diverticulitis are other things that you need to think about when it can in reality, be a ureteral stone.

01:14 Let's move on to a clinical case just to illustrat a point here.

01:17 A 39-year old woman presents to the clinic with new-onset gross hematuria of one day's duration.

01:23 She denies pain, nausea, history of trauma, no new medications including herbal remedies.

01:28 She's had a history of a femoral and abdominal wall hernia and those have been repaired and also notes strong family history of renal disease on her mother's side.

01:37 Physical exam is remarkable for a normal blood pressure.

01:40 and she has mild hepatomegaly and mild discomfort over the bilateral upper quadrants to deep palpation, otherwise the remainder of her exam is unremarkable.

01:48 Her labs show a normal serum creatinine and electrolytes.

01:51 Urine analysis shows no protein but greater than 40 red blood cells per high power field.

01:57 Her microscopic exam shows no cellular cast or crystals.

02:01 So what's the next step in figuring out why this woman is presenting with new-onset gross hematuria? Let's go through our clinical case and see if we have some diagnostic clues.

02:12 She has gross hematuria, taken together with the history of hernias, a strong family history of renal disease.

02:19 It really points to a genetic diseases like perhaps polycystic kidney disease.

02:24 She has hepatomegaly and mild discomfort to palpation reflecting that she may have underlying cystic disease.

02:32 And hematuria in the absence of proteinuria points to an extraglomerular source, included in that could be something like polycystic kidney disease with a hemorrhagic cyst So what's the next step that we want to do? We'd want to image this patient.

02:48 And here our result: We image our patient with a CT scan of the abdomen and pelvis non-contrast and what you can see here through this axial image of the kidneys is polycystic kidney disease.

03:00 This patient in fact has multiple cysts in each of her kidney taken along with her family history, then it really indicates that this patient has polycystic kidney disease and the cause of her painless hematuria, is due to a hemorrhagic cyst from her polycystic kidney disease.

03:20 So my point is not all haematuria is stones and you need to pay attention to what's going on with your patients.

03:28 So let's talk a little bit more about hematuria.

03:31 So gross hematuria is more common with larger stones, that means patients can see that with their naked eye It's often associated with loin pain and ureteral colic but not always, it can be painless.

03:45 So let's look more closely at some of the causes of hematuria.

03:49 There's hematuria due to glomerular disease.

03:52 That's an intrarenal cause, meaning that that patient has nephritic syndrome.

03:56 and those red cells typically will have dysmorphic features meaning that those membranes of the red blood cells look abnormal.

04:04 Patients can have hematuria from having interstitial nephritis or cystitis.

04:10 They can have a congenital malformation like medullary sponge kidney which causes tubular ectasia and then they can have red blood cells as well in their urine.

04:19 Papillary necrosis, this is something that's been associated with Phenacetin or analgesic neuropathy as well as sickle cell disease.

04:27 Trauma to the kidney, things like infection, either bladder infections with cystitis, prostatitis, acute pyelonephritis or even things like tuberculosis and schistosomiasis if you're in an endemic region.

04:41 Malignancies are also very common in terms of causing hematuria.

04:45 Painless hematuria oftentimes is described with renal cell carcinoma, we can see it certainly with transitional cell carcinoma of the urothelium, as well as prostate cancer in a pediatric population, Wilms tumors.

04:59 And of course like in our patient case, polycystic kidney disease typically from hemorrhagic cystic disease.

05:05 And finally last but not least is nephrolithiasis.

05:11 So other clinical manifestations of nephrolithiasis include urinary tract infection, a frequency or urgency to void.

05:19 Patients may also come in with asymptomatic urine abnormalities meaning that they have microscopic hematuria not visible to the naked eye, or low-grade proteinuria or perhaps sterile pyuria.

05:31 And remember sterile pyuria means that you have white cells in the urine in the absence of having bacteria.

05:38 Patients can also present with obstructive uropathy or acute kidney injury depending on where that stone is.

05:45 So for example if you have a bilateral staghorn calculi as shown in this image here, that takes up the entire renal pelvis and essentially obstructs outflow of urine.

05:55 or let's say you have a solitary kidney and you have a calculus right at that ureteropelvic junction, it'll obstruct outflow of urine and that patient will present with an obstructive uropathy and acute kidney injury.