immunoglobulin light - chain amyloidosis ( al ) is a rare systemic disease characterized by progressive tissue and organ extracellular fibrillar deposition . kidney spontaneous rupture is not a recognized complication in amyloidosis or autologous stem cell transplantation ( asct ) . we report the singular case of a bilateral spontaneous kidney rupture during asct for al with renal rescue . a 46-year - old caucasian female , affected by nephrotic syndrome , was diagnosed with al amyloidosis by renal biopsy ( figure 1 ) , performed on the left kidney ( maximal longitudinal renal axes 10.9 cm ) , in december 2006 , with an igg- as monoclonal protein . the data of laboratory examination at the time of diagnosis are listed in table 1 . a 46-year - old caucasian female , affected by nephrotic syndrome , was diagnosed as al amyloidosis by renal biopsy : ( a ) amyloid deposition ( congo red staining ) viewing by standard light microscopy and ( b ) polarized light microscopy ; apple green birefringence is elicited on polarization ( 100 ) . ( c ) immunofluorescence microscopy for lambda light chains of the same specimen ( frozen tissue ) ( 100 ) . data of laboratory examinations at december 2006 ( diagnosis of amyloidosis ) and july 2007 ( admission for asct ) scr , serum creatinine ; scys c , serum cystatin c. in july 2007 , she was considered suitable for asct and started the stem - cell mobilization with g - csf 10 g / kg / day , yielding 2.081  10 nc / kg ( 8.323  10 cd34 laboratory parameters showed serum creatinine ( scr ) , serum cystatin c ( scys c ) , urea , haemoglobin ( hb ) and platelets ( plt ) levels in the normal ranges , bence jones proteinuria positive , 24-h proteinuria in nephrotic range ( 4.5 g ) , serum albumin level 2.1 g / dl , and white blood cells ( wbc ) 4050/l ( table 1 ) . just before transplantation , she was submitted to a conditioning regimen consisting  as protocol  of melphalan ( 200 mg / m , total dosage 340 mg ) administered at day 3 before transplant . one day before asct , the patient presented a sudden onset of flank abdominal pain with symptoms and signs of a severe haemorrhagic shock . an urgent computed tomography ( ct ) scan of the abdomen and pelvis showed a severe right renal capsular bleeding with a voluminous haematoma ( 20 cm ) ( figure 2a ) . the pathological findings consisted of an ochre normal - dimension kidney ( 10.5  7  4.5 cm ) with large haemorrhagic lesions in medium and apical regions and diffuse subcapsular haemorrhages , with vascular aspect of hilar venous thrombosis . histologically , there were widespread amyloid deposits in the interstitium and vessel walls with a high intensive congo red - stained positivity ; no findings were found for vasculitis or for neoplastic . a. ct scan of the abdomen and pelvis showed a severe right renal capsular bleeding with a voluminous haematoma ( 20 cm ) . two days after surgical intervention , the patient underwent asct , and antimicrobial prophylaxis was started . however , she developed a sepsis due to pneumonia , in response to broad - spectrum antimicrobial therapy . during this time the patient presented a second haemorrhagic shock with left abdominal pain and anuria . at the time , coagulation times were within the normal range , while hyperfibrinogenaemia ( fibrinogen 533 mg / dl ) and a low plt count were present ( platelets 14 000/l ) . a ct abdomen showed a left renal laceration with a vast haemorrhage ( figure 2b ) . due to the high bleeding risk , because of the onset of acute renal failure , daily renal replacement therapy ( rrt ) in haemodiafiltration modality was started for a total of 10 sessions . however , 48 h after the last dialysis session the patient presented a septic shock status with aspergillus pneumonia , plus the onset of acute respiratory distress syndrome and anuria . she was submitted to non - invasive respiratory support and aggressive antifungal therapy ; cardiocirculatory system was maintained by vasoactive therapy , and new sessions of crrt ( in high - volume haemofiltration modality ) were started . net ultrafiltration rate was adjusted in each session according to the body weight and the better haemodynamic compliance . blood pressure and renal and respiratory functions gradually improved , and crrt was stopped . at day + 36 post - transplant , the patient was discharged with preserved diuresis , and laboratory tests for renal function were as follows : scr 2 mg / dl , urea 69 mg / dl , 24-h proteinuria 2.2 g , hb 13.4 g / dl , plt 47 000/l , wbc 3410/l , and serum  free light chain 9.13 mg / dl in urine . the follow - up at 24 months showed scr 1.48 mg / dl , urea 76 mg / dl , 24-h proteinuria 196.5 mg , absence of bence jones proteinuria and serum  free light chain 2.03 mg / dl . the deposition of immunoglobulin light - chain fragments damages several organs causing their progressive failure and death . the kidney is involved in 40% to 73% of patients [ 2,35 ] , and proteinuria is by far the most common manifestation . if on dialysis , these patients have a poor survival rate . although rare , spontaneous organ ruptures occur [ 68 ] , and seem to be due to the loss of vascular integrity leading to spontaneous bleeding and subsequent rupture . spontaneous subcapsular or perinephric bleeding of the kidney is described as a rare complication in renal cell carcinoma , angiomyolipoma and vascular diseases such as periarteritis nodosa ; moreover , rarely are spontaneous renal haematomas reported in chronic haemodialysed patients , particularly in those who have acquired renal cystic disease . in our patient , the ct scans performed to evaluate the eligibility for asct and then again to explain the rupture of kidneys did not show neoplastic lesions ; moreover , the immunological screening and the renal biopsy showed amyloidosis and excluded any kind of vasculitis or other immunological disorders . therefore , it is possible that the spontaneous renal rupture could be due to amyloidosis or to asct . in the presented case , renal vein thrombosis could be explained by nephrotic syndrome , a well - recognized condition associated with a hypercoagulability state . in fact , despite the underlying causes of the hypercoagulable state in patients with nephrotic syndrome that are not well understood , a variety of haemostatic abnormalities have been described , including decreased levels of antithrombin and plasminogen ( due to urinary losses ) , increased platelet activation , hyperfibrinogenaemia , inhibition of plasminogen activation , and the presence of high - molecular - weight fibrinogen moieties in the circulation . amyloidosis , however , is characterized by an increased bleeding risk , but adamu et al nevertheless , renal vein thrombosis is not recognized as a possible cause of renal rupture ; so with regard to the right kidney , we could speculate a spontaneous rupture secondary to vessel amyloidosis leading to venous thrombosis . a second hypothesis , is that the hilar venous thrombosis , due to nephrotic syndrome , was the possible cause of renal rupture . in the second episode of spontaneous renal rupture ( in which there was no nephrectomy ) first , a renal vein thrombosis can not be excluded due to the same procoagulant mechanisms suggested in the first rupture ; nevertheless , after a few days , diuresis restarted , so we must consider a spontaneous resolution of thrombosis after renal rupture ; moreover , the platelet count was very low because of the bone marrow suppression as a result of chemotherapy , and in this scenario , it is difficult to evoke a thrombotic cause . second , before the second kidney rupture , the patient was submitted to asct and therefore to granulocyte colony - stimulating factor ( g - csf ) . in the literature , organ spontaneous rupture secondary to asct is often related to an increase in organ size as a result of extramedullary haematopoiesis . the kidney is not a haematopoietic organ , and in the literature , there are extremely rare reports [ 1315 ] about the occurrence of a renal extramedullary haematopoiesis . in fact , it usually occurs in the reticuloendothelial system , involving the liver , spleen and lymph nodes , in association with some haematological disorders ( in particular myelofibrosis ) , as a response to erythropoiesis failure in bone marrow . in our patient , we did not report any failure of bone marrow erythropoiesis before chemotherapy , nor did renal histological findings ( for the right nephrectomized kidney or the left kidney ) support this rare possibility . third , a spontaneous renal rupture attributed to acute tubular necrosis could be considered , but in the literature , this complication is related only to allograft kidneys . finally , without any histological support , we were not able to determine the definitive cause of the second renal rupture , but a loss of vascular integrity leading to spontaneous bleeding and subsequent rupture is suggestive . in any case , suggested therapeutic approaches in kidney rupture are contrasting . some authors advocate radical nephrectomy due to the possibility of a small clinically unapparent renal cell carcinoma . in contrast , others have advised a conservative approach when diagnostic studies fail to demonstrate a significant pathology and clinical signs are stabilized . nevertheless , in many cases , the severe haemorrhage necessitates surgical exploration . in our patient , the first haemorrhagic event required nephrectomy to control the haemodynamic status . in the second event , a conservative approach was chosen because of the single - kidney status and the high bleeding risk . this strategy allows the patient to maintain a residual renal function without the need for dialysis . in conclusion , spontaneous renal rupture is a medical and surgical emergency which needs a rapid diagnosis and prompt treatment , and al amyloidosis should be included in the differential diagnosis . all the authors have any financial interests or arrangements with a company whose product was used in this study or is referred to in a manuscript , any financial interests of arrangement with a competing company , any direct payment from any source to an author(s ) for the purpose of writing the manuscript , and any other financial connections , direct or indirect , or other situations that might raise the question of bias in the work reported or the conclusions , implications or opinions stated  including pertinent commercial or other sources of funding for the individual author(s ) or for the associated department(s ) or organization(s ) , personal relationships , or direct academic competition .