Left Ureterocalycostomy With Ileal Interposition for Retroperitoneal Fibrosis in Patient With Erdheim-Chester Disease.

BACKGROUND: Erdheim-Chester disease (ECD) is a rare progressive non-Langerhans' cell histiocytic multisystem disorder with a broad spectrum of clinical manifestations, including infiltrative perinephric with ureteral involvement resulting in hydronephrosis, renal atrophy, and eventual renal failure. OBJECTIVE: To present a patient with ECD with bilateral renal/ureteral involvement managed with bilateral percutaneous nephrostomy tubes (PCNT) and trametinib who underwent bilateral robotic upper tract reconstruction, the first such published report. The video demonstrates only the left-sided repair, which posed specific challenges and demonstrates reconstructive techniques useful in complex upper tract repairs with limited tissue availability. MATERIALS AND METHODS: A 35-year-old male initially presented with baseline creatinine of 1.62 and split renal function; 30% right and 70% left by Lasix renogram. Extra-genitourinary manifestations of disease included cardiac hypertrophy and skin ulcers/lesions. Bilateral retrograde pyeloureterography showed proximal ureteral obliteration ∼4 cm bilaterally. Multiple management options were discussed including PCNTs, but patient elected for definitive repair. He was seen by Cardiology and Anesthesia and deemed to be optimized. He held his trametinib for 1week before surgery. We demonstrate a difficult ureteral dissection with fibrotic hilum preventing separation. Simultaneous ureteroscopy identified the distal extent of stricture which was excised, leaving a ∼15 cm gap. Downward nephropexy was performed with ultrasound guidance to identify an inferior calyx. Partial nephrectomy was then performed without vascular control due to hilar fibrosis. Ileal interposition was chosen to bridge the remaining ∼8 cm gap. Proximal ileo-calyceal and distal ileo-ureteral anastomoses were performed. We then placed a 30 cm × 7 Fr double-J ureteral stent in standard fashion. The ileum was secured to the renal pelvis to maintain a straight lie and an omental flap was secured in place. RESULTS: Immediate postoperative course was complicated by partial small bowel obstruction leading to a negative exploratory laparotomy and a subsequent episode of urosepsis. The patient is now voiding well without stents or PCNTs, without infections and with improving renal function, now with GFR (glomerular filtration rate) of 62 from 43 preoperatively. With aggressive hydration, patient has had no obstruction of the distal ureter with mucus. MRI Abdomen/Pelvis 6months later showed irregularity of the calyces with stable mild hydronephrosis. The patient continues to be medically managed on trametinib for his underlying disease, with surveillance for recurrent fibrosis and obstruction which has not yet occurred. CONCLUSION: Robotic ureterolysis and ureterocalycostomy with possible bowel interposition is a reasonable option for upper tract reconstruction in select patients with ECD.

A case of immunoglobulin G4-related retroperitoneal fibrosis and hypophysitis with antecedent respiratory disease followed by spontaneous remission and recurrence.

A 65-year-old man presented with apparent bronchopneumonia. After treatment with antibiotics, he showed eosinophilia. Computed tomography (CT) imaging revealed bilateral consolidation, ground-glass opacities with nodular consolidations, and pleural effusion. Lung biopsy showed organising pneumonia with lymphoplasmacytic infiltration in the alveolar septa and in the thickened pleura and interlobular septa. All pulmonary abnormalities spontaneously went into remission within 12 months. At 73 years old, a follow-up CT scan revealed small nodules in both lungs and the review of the head CT scan showed thickening of the pituitary stalk in studying prolonged headache. Two years later, he visited the hospital complaining of severe oedema on the lower extremities with high serum immunoglobulin (Ig)G4 186 mg/dl. A whole-body CT scan showed retroperitoneal mass surrounding aortic bifurcation and compressing inferior vena cava, pituitary stalk thickening and gland swelling, and enlarged pulmonary nodules. Anterior pituitary stimulation tests showed central hypothyroidism, central hypogonadism, and adult growth hormone deficiency with partial primary hypoadrenocorticism. Retroperitoneal mass biopsy showed storiform fibrosis and obliterative phlebitis with marked lymphoplasmacytic infiltration with moderate IgG4-positivity. Immunostaining of the former lung specimen revealed dense interstitial infiltration of IgG4-positive cells. These findings indicated metachronous development of IgG4-related disease in lung, hypophysis, and retroperitoneum, according to the recent comprehensive diagnostic criteria of IgG4-related disease. Glucocorticoid therapy ameliorated oedema, on the other hand, unmasked partial diabetes insipidus at the initial dose of the treatment. Hypothyroidism and retroperitoneal mass regressed at 6 months of the treatment. This case warns us that long-term follow-up from prodromal to remission is necessary for the treatment of IgG4-related disease.

Chronic periaortitis: A clinical approach.

Chronic periaortitis (CP) is a rare disease characterised by the presence of a fibro-inflammatory tissue typically enveloping the abdominal aorta, the iliac arteries and, in some cases, the nearby structures, such as the ureters and the inferior vena cava. Imaging plays a key role in the diagnosis and follow-up: computed tomography and magnetic resonance imaging scans are used to define the extension of the pathological tissue, whereas fluorodeoxyglucose positron emission tomography is the gold standard to establish the degree of its metabolic activity. CP must be distinguished from secondary forms of periaortic infiltration, which include malignant, infectious, and drug-related aetiologies. This review focuses on the clinical aspects of CP and the differential diagnosis with secondary cases, and aims to provide the clinician with a guide through this challenging clinical approach.

Minimally invasive ureterolysis and intraperitonealization of ureter for idiopathic retroperitoneal fibrosis; single center analysis of an erratic disease.

INTRODUCTION: Idiopathic retroperitoneal fibrosis is a known cause of obstructive uropathy. Ureterolysis is done when medical management fails or the presentation is at an advanced stage. Conventionally ureterolysis without omental wrap has been considered incomplete. Our Institute has experience of laparoscopic or robotic ureterolysis with intraperitonealization of the ureter alone and no other adjunctive procedure. This study retrospectively assesses the result of the procedure with patients presenting with varying severity of disease. METHODS: From 2008, all patients who underwent laparoscopic or robotic ureterolysis were analyzed retrospectively for pre-operative management, operative findings, and post operative outcomes. RESULTS: We operated and released nine renal units in seven patients. Two of the nine cases were performed robotically completely and the rest was performed by laparoscopic approach. Median follow up was 60 months. All patients documented resolution of symptoms. The mean post-operative creatinine at 1 year was significantly decreased to 1.47 ± 0.49 mg/dl in comparison to preoperative creatinine (p < 0.05). The postoperative mean ESR decreased significantly from a preoperative value of 58.2 ± 19.41 mm to 15.8 ± 17.23. The nuclear scan revealed unobstructed drainage and radiological imaging revealed resolution of hydronephrosis and fibrosis in all. The mean GFR on the nuclear scan after 3 and 12 months of surgery was 36.3 ± 4.33 and 40 ± 3.77, respectively. Thus, there was significant increase noted in GFR at 3 and 12 months in comparison to preoperative GFR (p < 0.05). CONCLUSION: Laparoscopic/robotic ureterolysis with intraperitonealization alone is secure and durable procedure for idiopathic retroperitoneal fibrosis needing surgical release.

Idiopathic retroperitoneal fibrosis with endometrial cancer: a case report and literature review.

BACKGROUND: Retroperitoneal fibrosis is a rare disease characterized by chronic nonspecific inflammation, which leads to clinical compression manifestations of retroperitoneal organs especially ureter. Approximately 70 percent of retroperitoneal fibrosis cases are idiopathic which has no clear etiology. This study reported a rare case of a 48-year-old woman presented with idiopathic retroperitoneal fibrosis and endometrial cancer. CASE PRESENTATION: A 48-year-old woman presented with irregular vaginal bleeding without abdominal pain, bloating or discomfort. The patient was diagnosed iRPF after splenectomy 13 years ago. Then she took prednisone for 2 years and took tamoxifen for about 11 years. She stopped taking the medication from October 2019 to May 2020 and then started taking tamoxifen again until November 2020. Two weeks after she stopped taking tamoxifen, she presented with irregular vaginal bleeding. Gynecological ultrasound revealed a thick endometrium with uneven echo enhancement and blood flow signals. Then diagnostic curettage was performed with pathological examination showed endometroid carcinoma. Later, the patient was admitted to Peking University Third Hospital for surgery. Preoperative imaging examinations, including CT, MRI, and PET/CT, all showed pelvic enlarged lymph nodes and they were highly suspected to have lymph node metastasis. The patient underwent laparoscopic surgical staging and enlarged lymph nodes in the pelvic and aortic regions were removed. Finally, the pathology confirmed that endometrioid adenocarcinoma and fibrosis, but there was no tumor infiltration in these enlarged lymph nodes. The patient is now in good condition. CONCLUSION: This case report stressed the difficulty to distinguish between lymph node metastasis and inflammatory hyperplasia by common imaging methods. Due to increased surgical difficulty among retroperitoneal patients, lymphadenectomy should be carefully evaluated to avoid additional surgical complications and over-treatment.

IgG4-related disease diagnosed in a paratesticular pseudotumor simulating malignancy, in a patient with retroperitoneal fibrosis.

IgG4 related disease is a term used to describe a fibroinflammatory condition characterized by storiform fibrosis, inflammation with a dense lymphoplasmocytic infiltrate rich in plasma cells expressing IgG4, and often, if not always, raised serum levels of IgG4. We report a case of a patient with a past history of retroperitoneal fibrosis presenting with a swollen left testicle, who underwent an orchidectomy due to suspicion of malignancy. The surgical specimen revealed a paratesticular pseudotumor with histopathological and immunohistochemical characteristics of IgG4 related disease. To the best of our knowledge, just nine such cases have previously been reported, of which only three were manifestations of systemic disease, as in the present case. Whilst it is important to recognize the clinical and radiological features of this entity, histopathology is often essential in order to confirm the diagnosis.

Comparison of Laparoscopic and Open Ureterolysis for Retroperitoneal Fibrosis: Results from a Tertiary Referral Center.

Objectives: To compare the surgical outcomes of open and laparoscopic ureterolysis procedures in patients requiring surgical treatment for ureteral obstruction caused by retroperitoneal fibrosis (RPF). Materials: This study was designed retrospectively. The clinical records of patients who underwent ureterolysis between January 2005 and April 2019 because of ureteral obstruction caused by RPF were examined. According to the type of surgery, the patients were divided into two groups as Group 1 (open ureterolysis) and Group 2 (laparoscopic ureterolysis). Demographic features, preoperative-postoperative renal functions, duration of follow-up with ureteral stents, and perioperative-postoperative complications were examined. The requirement of ureteral stent placement during the follow-up period was accepted as unsuccessful ureterolysis. Results: Ureterolysis was performed in 13 patients and 23 renal units. Eleven of these patients were men and two were women. The median age of the patients was 54 (44-68) years. There were six patients and 12 renal units in Group 1 and seven patients and 11 renal units in Group 2. Postoperatively, a total of four patients (30%) had minor complications (Clavien-Dindo 1-2) and one patient had a major complication (Clavien-Dindo 3a). Ureterolysis was determined to be effective in 21 of the renal units (91%) [11/12 (92%) in Group 1 vs 10/11 (91%) in Group 2]. No statistically significant difference was found between the groups in terms of the success and complication rates (p = 1 and p = 0.529, respectively). Postoperative hospitalization length and recovery time to return to normal preoperative activities were significantly shorter in Group 2 than in Group 1 (p = 0.011 and p = 0.041, respectively). Conclusions: The success and complication rates were similar between the open and laparoscopic methods for ureterolysis. Laparoscopic approach was advantageous over open approach in terms of postoperative hospitalization length and recovery time to return to normal preoperative activities.

Retroperitoneal Fibrosis Is Still an Underdiagnosed Entity with Poor Prognosis.

BACKGROUND: Retroperitoneal fibrosis (RPF) is a rare disease characterized by the presence of inflammatory and fibrous retroperitoneal tissue that often encircles abdominal organs including the aorta and ureters. Data on the incidence of this disease are limited. SUMMARY: The disease may be idiopathic or secondary to infections, malignancies, drugs, or radiotherapy. The idiopathic form is an immune-mediated entity and a part of the broader spectrum of idiopathic diseases termed chronic periaortitis, characterized by a morphologically similar fibroinflammatory changes in the aorta and surrounding tissues. Taking into account the dominant symptoms and clinical characteristics of patients with periaortitis, 2 subtypes of disease could be distinguished. The vascular subtype includes patients with nondilated aorta or with inflammatory abdominal aortic aneurysm, both with and without involvement of adjacent structures and with numerous risk factors for atherosclerosis. In the renoureteral subtype, obstructive uropathy manifesting with hydronephrosis and acute kidney injury is the predominant finding. Due to the variety of symptoms, diagnosis of RPF remains challenging, difficult, and often delayed. A series of diagnostic tests should be performed, in order to confirm the diagnosis idiopathic RPF. Laboratory workup includes evaluation of inflammatory indices and immunological studies. A biopsy and histopathological evaluation may be necessary to confirm diagnosis and differentiate the disease. Computed tomography, magnetic resonance imaging, and positron emission tomography are the modalities of choice for the diagnosis and follow-up of this disease. Management of ureteral obstruction, hydronephrosis, and aortic aneurysms often requires surgical evaluation and treatment. The pharmacological treatment of RPF has been evaluated in a few randomized trials and is mainly based on observational studies. Steroid therapy remains the gold standard of treatment. KEY MESSAGES: Nowadays, multidisciplinary team approach with clinical and diagnostic experience in both primary and secondary RPF as well as 2 major subtypes should be offered. Centers specialized in rare diseases with collaboration with other units and referral system yield the best possible outcomes.

Surviving complications of retroperitoneal fibrosis with intermittent relapses over a period of 20 years: case report and literature review / Sobrevivir a las complicaciones de la fibrosis retroperitoneal con recaídas intermitentes durante un período de 20 años: reporte de un caso y revisión de la literatura

Idiopathic retroperitoneal fibrosis is a rare fibro-inflammatory disease of varied etiology which usually originates around aorta and spreads caudally along Iliac vessels into adjacent retroperitoneum causing ureteral obstruction as the most frequent complication.A 53-year-old male patient presented with complaint of mild pain in both the legs off and on. On investigating further, we found that he had been struggling with intermittent relapses every 3-4 years for last 20 years since he was first diagnosed with Idiopathic Retroperitoneal Fibrosis. He was 33-year-old when he first developed the symptoms of anuria for 48 hours and was diagnosed with Idiopathic retroperitoneal fibrosis. This was followed by atrophy of left kidney and hypertension 6 years later, then hypothyroidism after another 3years and finally involvement of Inferior Vena Cava and acute Deep Vein Thrombosis of lower limbs after another 3-4 years. His deep vein thrombosis was well managed in time. He was put on glucocorticoids everytime he had a relapse and a complication.We did a review of literature to understand recent advances about its pathogenesis, diagnosis, investigations and management. We searched in PubMed using terms like retroperitoneal fibrosis alone and in combination with related terms such as Inferior Vena Cava thrombosis, Deep Vein Thrombosis, Tamoxifen, Methotrexate. This case is unique as it is very rare to find acute Deep Vein Thrombosis in Idiopathic retroperitoneal fibrosis without development of any collaterals when Inferior Vena Cava lumen is compromised to almost complete obstruction.After a follow up of 20 years patient is doing well in terms of physical activity and psychological wellbeing with anti-hypertensives, thyroxine and anti-coagulants. Is the disease-free interval actually free of the disease or it just subsided with immunosuppressants to become active after some time?

La fibrosis retroperitoneal idiopática es una enfermedad fibroinflamatoria rara, de etiología variada que generalmente se origina alrededor de la aorta y se propaga caudalmente a lo largo de los vasos ilíacos en retroperitoneo adyacente causando obstrucción ureteral como la complicación más frecuente.Reportamos el caso de un paciente varón de 53 años que se presentó con un dolor leve en ambas piernas. Al investigar más a fondo, descubrimos que había estado luchando con recaídas intermitentes cada 3-4 años durante los últimos 20 años desde que se le diagnosticó por primera vez fibrosis retroperitoneal idiopática. Tenía 33 años cuando desarrolló por primera vez los síntomas de anuria durante 48 horas y se le diagnosticó fibrosis retroperitoneal idiopática. Esto fue seguido por atrofia del riñón izquierdo e hipertensión 6 años después, luego hipotiroidismo después de otros 3 años y finalmente afectación de la vena cava inferior y trombosis venosa profunda aguda de las extremidades inferiores después de otros 3-4 años. Su trombosis venosa profunda se controló bien a tiempo. Le recetaron glucocorticoides cada vez que tenía una recaída y una complicación.Hicimos una revisión de la literatura para comprender los avances recientes sobre su patogenia, diagnóstico, investigaciones y manejo. Se realizaron búsquedas en PubMed utilizando términos como fibrosis retroperitoneal sola y en combinación con términos relacionados como trombosis de la vena cava inferior, trombosis venosa profunda, tamoxifeno, metotrexato. Este caso es único, ya que es muy raro encontrar trombosis venosa profunda aguda en fibrosis retroperitoneal idiopática sin desarrollo de colaterales cuando la luz de la vena cava inferior está comprometida hasta una obstrucción casi completa.Después de un seguimiento de 20 años, el paciente se encuentra bien en términos de actividad física y bienestar psicológico con antihipertensivos, tiroxina y anticoagulantes. ¿El intervalo libre de enfermedad está realmente libre de la enfermedad o simplemente disminuyó con inmunosupresores para activarse después de algún tiempo?

[Retroperitoneal fibrosis at the Ibn Sina University Hospital of Rabat: about 18 cases]. / Fibrose rétropéritonéale au CHU Ibn Sina de Rabat: à propos de 18 cas.

Retroperitoneal fibrosis (RPF) is a rare disease characterized by the formation of a fibro-inflammatory plaque in the retroperitoneal space in front of the abdominal aorta. It is responsible for the sheathing of the ureters. It is characterized by unspecific clinical signs, and it is often detected based on obstructive uropathy. We conducted a retrospective, descriptive study in the Department of Urology B and in the Department of Nephrology of the Ibn Sina University Hospital over a period of 10 years from January 2006 to December 2016. The study enrolled 18 patients, including 11 men and 7 women, with an average age of 51.4 years ± 11.2. Diagnosis was based on lumbar pain in 14 patients. Obstructive renal failure was reported in 15 patients and the diagnosis of RPF was based on uroscanner. Etiological assessment revealed 2 cases with a history of neoplasia, 2 cases of inflammatory disease and 1 case of retroperitoneal surgery; chronic drug intake was noted in more than half of the patients. In all patients, treatment was based on double J stent placement, while systemic treatment with corticosteroids and immunosuppressants was used on the basis of the evolutionary profile. Ureterolysis was immediately performed in 3 patients. Outcome was favorable, with significant improvement in renal function in 12 patients. A relapse occurred in 2 patients after 2 years of follow-up. Retroperitoneal fibrosis (RPF) should be suspected in patients with general signs associated with obstructive renal disease. Secondary causes should be systematically investigated, with particular emphasis on hyper IgG4 disease and neoplastic diseases.

The First Case of Eosinophilic Granulomatosis with Polyangiitis Simultaneously Demonstrating Various Clinical Manifestations with Retroperitoneal Fibrosis and Membranous Nephropathy.

The first case of eosinophilic granulomatosis with polyangiitis (EGPA) simultaneously demonstrating various clinical manifestations, including retroperitoneal fibrosis (RPF) causing hydronephrosis and membranous nephropathy (MN) leading to nephrotic syndrome, is presented. There have been no previous case reports demonstrating the simultaneous onset of these three disease categories with significant complex pathologies. This case was successfully managed by providing adequate combination therapies according to each disease category, leading to complete remission (CR) of all three diseases. In conclusion, we believe this case is extremely rare and clinically suggestive, and that these findings can be applied to a future phenotype-tailored treatment strategy for EGPA.

Outcomes of ureterolysis for primary retroperitoneal fibrosis: A single-center experience.

OBJECTIVE: To report our experience with ureterolysis for the management of retroperitoneal fibrosis. METHODS: The data of 25 patients who underwent ureterolysis due to primary retroperitoneal fibrosis between 2002 and 2017 were reviewed retrospectively. Initial symptoms, laterality, renal function status (initial/final), operation complications and serum creatinine levels (diagnosis/preoperative/6 months, 12 months postoperatively) were recorded. After surgery, patients were followed up by ultrasonography and serum creatinine levels. Patients with impaired results underwent furosemide renogram and/or late phase of computed tomography. Factors affecting final serum creatinine levels were evaluated. The χ2 -test was used for nominal data among groups. The level of statistical significance was set as P < 0.05. RESULTS: A total of 19 patients (76%) were operated bilaterally. The mean follow-up period was 46.2 ± 9.2 months. Among 44 operated renal units, non-functioning kidney developed in seven (15.9%). A total of 34 renal units (77.3%) did not require any additional surgical intervention, and two underwent balloon dilatation (4.5%), one (2.25%) followed with double J stent changes. Two patients developed end-stage renal disease secondary to bilateral unresolved obstruction. High final serum creatinine levels developed in eight (32%) patients without dialysis. Eight patients (32%) were treated with immunosuppressive therapy for systemic recurrence. There was a significant relationship between preoperative serum creatinine levels with final serum creatinine levels (P = 0.005). There was no statistically significant relationship between diagnosis serum creatinine levels with final serum creatinine levels and postoperative dialysis requirement (P = 0.79 and P = 0.817, respectively). CONCLUSIONS: Ureterolysis provides acceptable success with low complication rates in patients with retroperitoneal fibrosis. Preoperative high-serum creatinine levels can be considered as a risk factor for long-term renal impairment and these patients should be followed closely.

Retroperitoneal Sclerosing Lipogranuloma in an Adolescent With Congenital Atresia of the Inferior Vena Cava: Case Report and Literature Review.

Sclerosing lipogranuloma (SLG) in children is a rare, benign disease of unknown etiology suspected to be due to abnormal fatty tissue reaction. A 13-year-old girl presented with progressively worsening back pain. Cross-sectional imaging identified a retroperitoneal mass compressing the left ureter as well as infrarenal inferior vena cava atresia with extensive venous collaterals and chronic partially occlusive thromboses of the iliac veins. Surgical biopsy was consistent with SLG and it resolved spontaneously. SLG is typically a disease of adulthood but may be seen in children. The association between inferior vena cava atresia with venous thrombosis and development of SLG has not been reported previously.

Adolescent IgG4-related retroperitoneal fibrosis with left lower extremity edema as the first symptom: A case report. / 以左下肢水肿为首发症状的青少年IgG4ç›¸å ³æ€§è ¹è†œåŽçº¤ç»´åŒ–1例.

IgG4-related retroperitoneal fibrosis is a type of IgG4-related diseases. The etiology is still unclear. It is often classified as idiopathic retroperitoneal fibrosis, but the pathological process and clinical results between them are different. Therefore, the differential diagnosis of them is very important. An 18-year-old patient was admitted to the Second Xiangya Hospital of Central South University due to "left lower extremity edema for 1 and a half month" on December 19, 2019. In examination of PET/CT, the starting point of the left aorta-intra-thoracic artery showed a soft tissue density lump with increased sugar metabolism, which indicated a suspected malignant tumor, and dilatation of the left renal pelvis and ureter. On January 8, 2020, the patient was performed pelvic edema excision, ureterectomy and anastomosis. The postoperative examination results were considered as IgG4-related disease. As a rare systemic disease, early correct diagnosis and precise and individualized treatment can alleviate the suffering of patients and ensure that patients are minimally traumatized.

[Clinical features of hydronephrosis induced by retroperitoneal fibrosis: 17 cases reports].

OBJECTIVE: To investigate the clinical features and outcome of hydronephrosis induced by retroperitoneal fibrosis (RPF), and to evaluate the effect of corticosteroid based therapy combined with surgical intervention of ureteral obstruction. METHODS: A total of 17 RPF patients with hydronephrosis hospitalized in Peking University International Hospital from May 2016 to December 2019 were analyzed retrospectively. RESULTS: The median age was 56 (53, 65) years, the male to female ratio was 2.4 : 1, and the disease duration was 4.00 (0.83, 8.00) months. The initial symptoms included back pain (9 cases), abdominal pain (6 cases), oliguria (2 cases) and lower limb edema (3 cases). Eight patients presented left hydronephrosis, 1 right hydronephrosis and 8 bilateral hydronephrosis. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were both elevated in 13 patients (76.5%, n=17). Immunoglobin (Ig) G4 increased in 5 cases (29.4%, n=17). IgG, IgE and IgA increased in 4 cases (30.8%, n=13), 4 cases (30.8%, n=13) and 1 case (7.7%, n=13), respectively. Among 12 patients who underwent biopsy, 3 patients were diagnosed with IgG4-relate disease. The level of IgG4 in the tissues varied, 6 cases expressed less than 10 per high power field (HPF) or no expression (50.0%). Only 2 cases expressed 10-30/HPF (16.7%), and 4 cases revealed more than 30/HPF (33.3%). Among the 17 patients with ureteral obstruction, no urinary drainage procedure was needed in 4 patients who had mild ureteral obstruction, whereas, ureteral stenting was carried out in the other 13 cases before drug treatment. Time was too short to evaluate the effect of urinary drainage procedures in 4 patients. For the rest, ureterolysis had to be performed in 3 cases after failed ureteral stent insertion. Successful drain removal was accomplished in all of these 9 patients and the mean time to drain removal was (6.7±3.0) months. In addition, 10 patients had complete medical records after an average follow-up time of 5 (3-13) months. Levels of ESR, CRP, IgG4, IgG, IgE, IgA were 54.0 (36.3, 98.5) mm/h, 26.8 (8.7, 53.0) mg/L, 1.34 (0.55, 3.36) g/L, 16.3 (13.0, 21.1) g/L, 40.5 (31.4, 203.0) IU/mL, 2.51 (1.82, 3.25) g/L at baseline, which all decreased predominantly after treatment. ESR, CRP, IgG4, IgG, IgE and IgA dropped by 38.5 (23.5, 54.3) mm/h (P < 0.01), 23.0 (5.5, 52.0) mg/L (P < 0.05), 0.92 (0.40, 2.85) g/L (P < 0.01), 6.5 (1.7, 9.1) g/L (P < 0.05), 23.7 (4.8, 162.0) IU/mL (P < 0.05) and 0.77 (0.32, 1.26) g/L (P < 0.05), respectively. Size of mass measured by CT/MRI imaging became smaller significantly and hydronephrosis relieved. CONCLUSION: Onset of RPF is insidious and lack of specific initial symptoms. Corticosteroid based therapy combined with surgical intervention of relieving obstruction is effective.

Implications of Erdheim-Chester disease and percutaneous renal access.

Erdheim-Chester disease (ECD) is a rare systemic histiocytosis with urologic manifestations in a majority of affected patients. An important manifestation is a pronounced retroperitoneal fibrosis with reported dense inflammatory rind surrounding the kidneys. We report a case of a patient with large stone burden necessitating percutaneous nephrolithotomy and the implications related to his Erdheim-Chester-related retroperitoneal fibrotic changes. Foreknowledge of these implications may inform perioperative counseling and surgical planning to maximize opportunity for successful outcomes.

La fibrose rétropéritonéale idiopathique.

Retroperitoneal fibrosis (RPF) is a rare disease characterized by the presence of fibro-inflammatory tissue around the aorta entrapping the adjacent structures. RPF can be idiopathic or secondary to many disorders. The physiopathology is unknown but can be part of the spectrum of IgG4 related diseases. Imaging studies and inflammatory markers are essential for initial evaluation and follow-up. Biopsy is usually not recommended. The first line of treatment is corticosteroids associated or not with immunosuppressive drugs. In case of ureteral obstruction with renal failure, ureteral stent placement or nephrostomies are recommended. Initial response to treatment is usually good but relapses are frequent.