Renal Replacement Lipomatosis Research Articles

Renal replacement lipomatosis with granulomatous inflammation – A case report and review of literature

Renal replacement lipomatosis can be defined as the proliferation of fibrofatty tissue which subsequently replace the renal parenchyma. It is usually benign unilateral and occurs as a result of severe atrophy or destruction of the renal parenchyma, due to a calculus with secondary proliferation of renal sinus, renal hilus, and perirenal fatty tissue to a variable extent.A 55yr old female presented to surgeon with history ofpain and swelling in right flank. On CECT abdomen there was seen non functional right kidney with staghorn calculi along with perirenal abscess. Patient was treated with nephrectomy and drainage of collection. Intraoperatively Perirenal Abscess extending to psoas and iliopsoas region along with dense adhesion between kidney and liver was found. The multiple sections studied from the lesion showed extensive fibrofatty tissue with few tubule like structures lined by cuboidal epithelium and containing dense eosinophilic secretions. There is seen mixed inflammatory infiltrates with granulomas. Histological features confirmed that Renal replacement lipomatosis with granulomatous inflammation.The clinical importance of RRL is that it stimulates fat-containing tumors in the kidney or its vicinity such as lipomas, angiomyolipomas and liposarcomas can be misdiagnosed preoperatively. Hence this case report has been presented to create awareness of this condition among the pathologist and practicing urosurgeons.

Histomorphological Analysis of Nephrectomy Specimens

Introduction: For a range of kidney abnormalities, including both neoplastic and nonneoplastic disorders, nephrectomy is a popular surgical treatment. We conducted this study to examine the range of lesions found in the nephrectomy specimens obtained and to ascertain the distribution of these lesions by age and sex. Materials and Methods: This study was conducted in the department of pathology, from 2017 to 2022. All nephrectomy specimens received during 5 years were included. Results: The spectrum of renal lesions observed in the study included both neoplastic (43.75%) and nonneoplastic (56.25%) conditions. Nineteen patients were males (59.37%) and 13 were females (40.62%) (M: F = 1.4:1). The most common entity in the nonneoplastic category was chronic pyelonephritis (n = 9, 28.12%). In our study, we documented two unusual cases of renal replacement lipomatosis (RRL), a type of pseudotumor related to nonfunctioning kidneys. Fourteen patients underwent nephrectomy for neoplastic conditions such as Wilm's tumor and renal cell carcinoma (RCC). Conclusion: Nephrectomy for the nonneoplastic condition was performed more frequently in our series. Histopathological evaluation of nonneoplastic nephrectomy specimens must be thoroughly considered, particularly in unusual circumstances such as RRL, where a preoperative erroneous initial impression of a malignant lesion such as angiomyolipoma or liposarcoma is possible.

177 Renal Replacement Lipomatosis: An Unexpected Finding on Kidney Imaging

177 Renal Replacement Lipomatosis: An Unexpected Finding on Kidney Imaging

Renal replacement lipomatosis - A rare but also underdiagnosed entity

Renal replacement lipomatosis (RRL) is a rare condition that occurs as an end result of renal atrophy or replacement of renal parenchyma by excessive lipomatous tissue in renal sinus and perinephric space. We reported a case of RRL presented in our tertiary health centre. Left Nephrectomy was performed kidney sent to our department for histopathology examination and after extensive literature search, a diagnosis of RRL was given. In majority of cases, RRL is associated with renal calculi. Idiopathic variety of RRL is not common. It is a rare entity and due to lack of experience the diagnosis may be missed. It has to be differentiated from other fat-containing tumors such as xanthogranulomatous pyelonephritis, renal lipomas, liposarcoma and angiomyolipoma. Keywords: RRL (Renal Replacement Lipomatosis), Idiopathic, Nephrectomy, Adipose tissue.

Renal Replacement Lipomatosis Presenting as Hematuria

Renal replacement lipomatosis (RRL) is an extremely rare condition. It is thought to be a spectrum of degenerative process classically characterized by extensive abundance of adipose tissue in kidney. RRL is associated with long standing inflammation and stone disease in 70% of cases. In severe cases, it may lead to complete parenchymal destruction. Rarely, RRL may mimic fatty neoplasm of kidney. We report a 62-year-old male with renal replacement lipomatosis associated with stone disease presenting as hematuria.

Renal Replacement Lipomatosis—A Rare but Often Underdiagnosed Cause of Progressive Renal Damage in Calculus Disease

Renal replacement lipomatosis is a rare condition characterized by extensive fat deposition in hilum with parenchymal thinning and progressive detoriation of function.1-4 Though uncommon, it should be considered as a possibility in patients with history of intervention for stone disease.5,6 Correct diagnosis can be easily established by cross sectional imaging and is helpful to counsel patients about the possibility of progressive functional detoriation and poor salvageability of the affected kidneys.7-10 Here, we present 2 patients with previous history of intervention for calculus disease who had developed progressive renal damage due to RRL with one patient ultimately needing nephrectomy.

Rare case of renal replacement lipomatosis with xanthogranulomatous pyelonephritis

We report a relatively rare case of renal replacement lipomatosis (RRL) with coexistent xanthogranulomatous pyelonephritis (XP), depicting most of the radiological findings RRL and XP has several similarities in terms of clinical background as triggering mechanism is same i.e. chronic calculus disease and inflammation in most of them. Being rare entity diagnosis is usually missed due to lack of experience.

Xanthogranulomatous Pyelonephritis A Review and Update of the Literature

Xanthogranulomatous pyelonephritis (XGP) is a rare chronic destructive granulomatous inflammatory process that affects sporadically the parenchyma of the kidney and the disease tends to be associated in many cases with long-term urinary tract obstruction, urinary tract infection and also in cases with calculi within the kidney. XGP does affect females more commonly in comparison with males, it does affect all age groups including newly born up to the elderly. Majority of the patients tend to be symptomatic and some of the symptoms could include: pyrexia, flank / loin / abdominal pain, palpable mass in loin/abdomen/costovertebral region, weight loss, visible haematuria. There may be associated diabetes mellitus, obesity, or immune deficiency. There may be anaemia and leucocytosis upon blood tests. Urine cultures may grow Escherichia coli, or proteus but in other situations the urine culture could be negative. Ultrasound scan of renal tract, CT and MRI scan of abdomen and pelvis tend to be undertaken in the assessments of patients. CT scan has globally been the establishment of radiology imaging diagnosis. Radiology imaging may demonstrate focal or diffuse XGP but the diffuse form is more common. It may reveal multiple low-attenuated cystic masses in the kidney, calculi in the kidney, hydronephrosis / dilated calyces / bear’s paw appearance in some cases. Macroscopy examination of the specimen of the kidney would tend to show multiple yellow nodules around calyces, and the lesion may form a mass or be infiltrative. Pathology examination of specimens of XGP would tend to show granulomatous inflammatory infiltrate that consists of neutrophils, lymphocytes, plasma cells, xanthomatous histiocytes, as well as multi-nucleated giant cells. Immunohistochemistry staining may show positive staining for CD68. Some of the differential diagnoses include: clear cell carcinoma of the kidney, papillary renal cell carcinoma, sarcomatoid renal cell carcinoma, leiomyosarcoma, malakoplakia of kidney, megalocystic interstitial nephritis, and renal replacement lipomatosis. Majority of diffuse cases have been treated by nephrectomy and antibiotics and some focal cases have been treated by partial nephrectomy and antibiotics but on very rare occasions cases have been treated by drainage of the abscess with biopsy and in conjunction with antibiotics. Percutaneous nephrostomy has also been undertaken pre-operatively to decompress the kidney by draining the abscess in the occasional case.

Late and Rare Complications of Urolithiasis: Perinephric Abscess and Renal Replacement Lipomatosis

Background: Perinephric abscess and renal replacement lipomatosis (RRL) as a late and rare complications of urolithiasis.Case presentation: We report the case of a 62-year-old Kazakh woman who suffered for a long period of time from back pain,weakness (has been treated with confirmed osteochondrodystrophy) and was not aware about her kidney stones. She hadnever had hematuria or renal colic and urgently was admitted in a serious condition with large palpable abdominal mass. Thediagnostic workup, differential diagnosis, surgical management, medical follow-up and a review of the literature presented.Persistent back pain and weakness for several years were caused by nephrolithiasis and its late and rare complications likeRRL. Only one of the acute complications of nephrolithiasis as perinephric abscess attracted the attention of urologists andmade it possible to set up the correct diagnosis. Surgical management of the hephrolithiasis complications (urgent drainage ofperinephric abscess and delayed nephrectomy [because nonfunctioning kidney with multiple stones as a nidus of infectionsand RRL] after stabilization of patient’s condition was performed.Conclusion: Occasionally urolithiasis may mimic signs of spine disease, so in patients with persistent back pain which did notrespond to conventional therapy of this pathology should be excluded the hephrolithiasis. Non-treated urolithiasis may lead toloss of the kidney function and development of life-threatening acute complications like perinephric abscess and later – renalreplacement lipomatosis.

Renal Replacement Lipomatosis: From Conception to Birth

Renal replacement lipomatosis is a rare disease characterized by renal parenchymal atrophy and proliferation of inflammatory and fatty cells within the renal sinus, hilum, and perirenal region. The exact pathogenesis is unknown, however more than 75% of cases are associated with renal stones. Here, we provide images from a case with 10 years of follow-up, outlining the radiographic progression of the disease through time. Although only histopathology can confirm the diagnosis, high clinical suspicion in combination with the radiographic findings can differentiate the disease from other fat-containing entities.

Idiopathic renal replacement lipomatosis: A diagnostic and therapeutic challenge.

Renal replacement lipomatosis is a rare benign renal disorder where the renal parenchyma is replaced by mature fatty tissue. It poses a diagnostic challenge to the clinicians due to an unusual presentation and clinical features. The disease usually presents in middle age with vague pain in the affected flank and variable urological symptoms. Although the condition is preceded by calculus disease or chronic inflammation, as an extremely rare occurrence, it can occur without any pre-existing condition, as in our case. Increasing awareness among the surgeons about the existence of such a condition will help the surgical fraternity to diagnose and manage such cases properly.

Renal Replacement Lipomatosis with Psoas Abscess Mimicking as Xanthogranulomatous Pyelonephritis

Renal replacement lipomatosis also known as fibrolipomatosis is a rare chronic pathological condition of the kidney characterized by atrophy and damage to renal parenchyma with excessive proliferation of fat beginning from renal sinus and gradually replacing entire kidney by a fatty pseudotumor. We are presenting a case report of renal replacement lipomatosis in an elderly male with the long-term history of renal stones and coexistent psoas abscess on imaging mimicking as xanthogranulomatous pyelonephritis. Role of (computed tomography) CT imaging is described as preferred modality of investigation to describe unique features of this disease, to differentiate it from xanthogranulomatous pyelonephritis and as a roadmap to surgery.

Renal Replacement Lipomatosis—A Rare Benign Condition

Introduction: Renal replacement lipomatosis is a rare condition that occurs at the end of the spectrum of renal tissue replacement by fat. It is usually unilateral and occurs as a result of severe renal atrophy or destruction usually due to chronic calculus disease, chronic pyelonephritis and renal tuberculosis. The most commonly used diagnostic investigation remains CECT (contrast enhanced computed tomography) scan. Herein we report our series of patients with total renal replacement lipomatosistreated by nephrectomy. Materials & Methods: We retrospectively reviewed our hospital data for cases of RRL, presented and treated during the period Jan. 2006-Dec. 2015. The age, gender, presenting symptoms, clinical and laboratory findings were noted. The indications for surgery, postoperative outcomes and complications were similarly noted and analyzed. Results: Five patients (three females and two males) with a mean age of 48.4 ± 3.2 years presented with symptoms of pain. Computed tomography (CT) in these patients showed the affected kidney to be completely distorted and replaced by ill-defined fatty attenuating lesion. Open nephrectomy was done in all these patients. Histo-pathological report (HPR) revealed features of RRL with renal calculi. Conclusions: Renal replacement lipomatosis is an uncommon entity, and one should have a high index of suspicion when dealing with suspicious lesions similar to xanthogranulomatous pyelonephritis. Specific imaging, operative, and pathological differences may provide clues for the differential diagnosis.

Extensive renal sinus lipomatosis in xanthogranulomatous pyelonephritis simulating liposarcoma

ABSTRACTRenal replacement lipomatosis is a condition characterized by varying degrees of renal parenchymal atrophy and perirenal fibrofatty proliferation secondary to chronic inflammation such as xanthogranulomatous pyelonephritis. In severe cases, imaging findings can be misdiagnosed as retroperitoneal liposarcoma.

A rare case of incidentally detected renal replacement lipomatosis

We present a case of incidentally detected renal replacement lipomatosis in an Indian patient of 90 years who presented to us for chest evaluation. On Chest X-ray, we didn't find any chest abnormality except scoliosis. A staghorn calculus of size 5.5*3.7 cm was noted in left kidney for which a noncontrast CT scan was ordered. NCCT revealed a staghorn calculus in left renal pelvis with replacement lipomatosis, atrophic cortical parenchyma and patchy areas of low attenuation in renal parenchyma.

Renal sinus lipomatosis in transplant kidney

Renal sinus lipomatosis is a rare entity where there is abnormal proliferation of sinus fat. Fat proliferation can also occur in perinephric and periureteric regions. It is a benign condition which does not give rise to symptoms or any renal impairment. However, severe form of this condition, i.e. renal replacement lipomatosis, leads to atrophy of renal parenchyma, thereby leading to impairment of renal functions. Here, we report a case of renal sinus lipomatosis in a transplanted kidney, which is even rarer and has been reported in less than 10 previously reported cases in the English literature.

The Evaluation of Renal Replacement Lipomatosis with Computerized Tomography and Magnetic Resonance Imaging Findings: A Case Report

Renal sinus lipomatosis is a nontumorous renal lesion that defines the parenchymal atrophy related to adipose tissue proliferation in the renal sinus. Renal replacement lipomatosis (RRL) is a massive version of renal sinus lipomatosis. We aim to define RRL in a patient with the computed tomography (CT) and magnetic resonance imaging (MRI) findings.

RENAL LIPOMATOSIS

Replacement lipomatosis is thought to be a spectrum of degenerative process. The mildest form is called renal sinus lipomatosis and is usually associated with obesity, atherosclerosis or use of exogenous steroids and it has no clinical significance, while renal replacement lipomatosis is associated with long-standing inflammation and calculi as in this case. The current case report highlights the benefit of imaging techniques for suggesting this condition since early diagnosis and relieving calyceal obstruction can improve renal function and hopefully prevent progressive cortical atrophy while deficient techniques and reports may end with impaired renal function and unfortunately subsequent nephrectomy.

Appearance of Renal Replacement Lipomatosis on Computed Tomography: Rare pseudotumour.

An 81-year-old male patient presented to the Urology Department of GATA Haydarpasa Training Hospital, Istanbul, Turkey, in May 2014 complaining of left lumbar pain and a sense of abdominal fullness. On physical examination, left lumbar tenderness and a palpable mass were observed. A urine analysis showed an increased number of red blood cells. Plain abdominal radiography demonstrated soft tissue density at the left upper quadrant pushing the colon segments medially [Figure 1]. Abdominal ultrasonography revealed a significant increase in the size and echogenicity of the left kidney and its margin could not be clearly differentiated from the surrounding fat tissue. In addition, a decrease in the left renal parenchymal thickness was noted. Figure 1: Plain abdominal radiograph showing a mass with soft tissue density in the left upper quadrant pushing the colon segments medially (arrows) in a patient with renal replacement lipomatosis. Computed tomography (CT) and magnetic resonance imaging (MRI) were performed without the administration of intravenous contrast due to elevated serum creatinine levels. The CT scan [Figure 2] and axial T2-weighted MRI images revealed a fatty mass in the left kidney (approximately 22 × 18 × 14 cm in size) with areas of linear and patchy fibrous tissue. The mass caused significant enlargement of the left kidney and distortion of the surrounding structures. There were no areas of restricted diffusion within the lesion on diffusion-weighted images. A biopsy of the mass was performed and a pathological examination revealed mature fat tissue. As a result of these findings, the left renal mass was considered to indicate renal replacement lipomatosis (RRL). Ultrasonography performed three months after the initial diagnosis revealed no changes in the size and imaging characteristics of the lesion. Figure 2: Non-contrast computed tomography showing a fatty renal mass (arrows) in a patient with renal replacement lipomatosis. The mass caused significant left renal enlargement and distortion on the surrounding structures.

Late-Onset Development of Renal Sinus Lipomatosis in a Transplant Patient on Sirolimus

Late-Onset Development of Renal Sinus Lipomatosis in a Transplant Patient on Sirolimus