Unusual causes of Hematuria in dialysis patients: Diagnostic dilemma, risks and management.

Two male patients with end-stage renal disease (ESRD) developed a spontaneous hemorrhage of one of their native kidneys and were referred to our institution. Symptoms included sudden onset abdominal pain, hematuria and shock. Symptoms were associated with a hemoglobin decrease. Computerized tomography (CT) was done and nephrectomy undertaken in both the cases. Histologic findings confirmed bleeding and there was no abnormality other than those related to renal insufficiency (cysts and atrophy). In chronic hemodialysis (HD) patients with hematuria, if other common causes are not identified spontaneous subcapsular or renal cyst rupture should be kept in mind. Surgery is our preferred treatment because of the diagnostic dilemma of tumors and the potential mortality of massive hematomas in morbid patients.

INTRODUCTION

Spontaneous perinephric or subcapsular bleeding of the kidney is an uncommon entity. Renal cell carcinoma, angiomyolipoma or vascular diseases such as polyarteritis nodosa (PAN) are the most commonly implicated etiological factors. Rarely, spontaneous hematomas have been reported in chronic hemodialysed patients, particularly in those who develop acquired renal cystic disease (ARCD).[123] We recently treated 2 patients with ESRD for spontaneous renal hemorrhage. We describe our diagnosis and treatment modalities and discuss the management.

CASE REPORTS

Case 1

A 63-year-old man suffering from ESRD on maintenance HD for the past 2 years, was admitted with right flank pain and intermittent hematuria for one month. Previous ultrasound showed bilaterally small kidneys, each measuring about 6 cm. There was a fall of hemoglobin of 3 g/dL with development of postural symptoms and he also noticed a new onset mass in the right upper abdomen. Patient had a session of HD about a week back. On examination, he was pale, heart rate was 90/min, respiratory rate 18/min and his blood pressure was 130/90 mmHg. Abdomen was soft, non-tender, a 10 × 12 cm hard palpable lump was occupying the right hypochondrium and lumbar regions. There was no free fluid in the abdomen. Abdominal ultrasound revealed heteroechoic mass in the right kidney with multiple septations. Abdominal CT scan revealed a 10 × 10.3 × 11 cm well-defined predominantly hypodense mass with mean density of 19 HU, replacing the upper and mid-pole of the right kidney. There was peripheral wall enhancement with solid enhancing component within it (56 HU). Multiple enhancing septae were seen within it. Right renal vein and inferior venacava were normal [Figure 1a]. Blood investigation revealed hemoglobin of 8.3 g/dL, hematocrit 28%, platelets 1,24000 /μL, INR 1.06, albumin 3.8, urea 73mg/dL, creatinine 8.4 mg/dL and serum potassium of 6.2 mEq/dl. The patient received 2 units of packed red blood cells during hemodialysis. On considering all available reports, a diagnosis of right renal mass, probably of renal cell carcinoma was made. He underwent open right radical nephrectomy and gross specimen revealed a solid renal mass [Figure 1b]. On cutting the specimen whole pelvicalyceal system (PCS) was filled with blood clots [Figure 1c] and no growth was detected in PCS [Figure 1d]. A detailed histopathological evaluation revealed changes of chronic glomerulonephritis with no evidence of malignancy, vascular malformations or PAN. Postoperatively, the patient is on HD and awaiting renal transplantation.

Figure 1a

CT scan showing hypodense mass with peripheral wall enhancement with solid enhancing component within it

Figure 1b

Photograph of nephrectomy specimen showing features of a solid mass

Figure 1C

Cut-section of the nephrectomy specimen showing blood

Figure 1d

Cut-section showing parenchyma replaced by cysts with no evidence of any solid mass

Case 2

A 50-year-old male with ESRD, on hemodialysis since 14 months, awaiting renal transplantation presented with complaints of progressively increasing acute left flank pain, and was referred to the emergency from another centre. During evaluation for the cause of chronic kidney disease, bilateral shrunken kidneys were noted. No biopsy was performed and patient was declared ESRD and initiated on maintenance HD. There was no history of hematuria. This patient was hypertensive and diabetic for more than 10 years. Hemoglobin fell by 4 g% inspite of 6 units of blood transfusion. He presented to the emergency department with features of shock. On evaluation, patient was pale with a blood pressure of 86/60mm of Hg. Platelet count was 2.85/μL and coagulation parameters were normal. After fluid resuscitation and stabilization, CT scan revealed large perirenal hematoma with compressed atrophic kidney [Figure 2a]. Pain and lump gradually increased with progressive fall in hemoglobin, which led to exploration and nephrectomy with removal of perirenal hematoma. Operative finding revealed a large perirenal hematoma with atrophic kidney [Figure 2b]. On gross examination of the specimen, outer surface showed scars and focal areas of granularity. On cut-section cortico-medullary junction was indisntinct and PCS was filled with blood clots. Section of the kidney examined showed globally and focally sclerosed glomeruli with atrophic tubules. Interstitium was studded with lymphocytic infiltrates at places. No ulceration or granulomas were noted.

Figure 2a

Non-contrast CT showing left perinephric hematoma

Figure 2b

Picture showing blood after evacuation of the hematoma, with a small atrophic kidney

DISCUSSION

Spontaneous renal hemorrhage is a rare condition, and usually confined to the retroperitoneum. Spontaneous renal hematoma was initially described by Wunderlich in 1856.[4] Although it may present with “Lenk's triad” consisting of acute flank pain, tenderness and symptoms of internal bleeding, various presentations have been described in the literature. The process consists of atraumatic disruption of the renal parenchyma, with subsequent hemorrhage into the subcapsular or perinephric space. The most frequent etiologies of bleeding include renal carcinoma, angiomyolipoma and vascular diseases, of which PAN is the most common.[56] Inflammation and cystic disease are less frequent. Rarely, no underlying abnormality of the kidney can be found.

This clinical entity has been reported in chronic hemodialysed patients[127] as well as in uremic patients and in native kidneys of renal transplant recipients.[7] Several factors such as heparinization during dialysis, functional platelets’ abnormalities, intimal arterial fibrosis or oral anticoagulant therapies often combine to cause spontaneous hematoma of the kidney.[8] ARCD occurs in up to 95% of prolonged dialysis patients.[9] It is a bilateral disorder characterized by the development of numerous fluid-filled cysts that predominate in the cortex.[10] Cysts do not develop in any other organ in contrast to autosomal dominant polycystic kidney disease. Its evolution is progressive, the probability of presenting ARCD increases over time.[3] Bleeding in ARCD is different from that observed in polycystic kidneys where the hemorrhage is limited to one or several cysts and does not spread into subcapsular or perinephric space and is therefore not life-threatening. Renal ruptures in hemodialysed patients are usually treated with blood transfusions and close surveillance.[1] If the patient is on any anticoagulation, it should be discontinued. Additional vitamin K supplementation can be necessary as well as correction of any other hemostatic disorders such as thrombocytopenia.

Ultrasound is extremely valuable for rapid identification of the condition. Sometimes, it might be misdiagnosed as renal tumor or an evolving abscess.[11] CT is highly sensitive for diagnosis but not confirmatory. It gives valuable information regarding the cause of hematoma.[12]

All patients underwent a nephrectomy because of persistent bleeding responsible for anemia and massive hematomas. Moreover, the possibility of underlying malignancy must always be kept in mind even though CT does not always show specific finding. We therefore decided to perform nephrectomy in this situation. Nevertheless, a conservative approach is also possible. Pak et al., reported a case of spontaneous subcapsular hematoma managed conservatively and then carefully followed in order to rule out a renal tumor that could have given rise to the hemorrhage.[2] In a recent publication Bensalah et al., published their experience of 8 patients with spontaneous rupture of non-tumoral kidneys in patients of ESRD. ESRD with massive hematomas requiring surgical intervention in all the cases. However, the reported mortality in this series was 38%.[13]

CONCLUSION

In chronic hemodialysis patients with hematuria, if other common causes are not identified spontaneous subcapsular or renal cyst rupture should be kept in mind. A CT scan should be performed to objectively assess the hematoma and to rule out other causes of spontaneous renal rupture. Surgical intervention is the preferred modality in cases of suspected tumors or massive hematomas.