Una masa renal poco común en una adolescente ­ presentación de caso y revisión de la literatura / An Unusual Renal Mass in Adolescent ­ Case Report and Literature Review

Introducción Las neoplasias renales en la población pediátrica y adolescente son raras, entre el 6% y el 7% de las masas en pediatría. En adolescentes plantea un desafío clínico importante. Presentan variables manifestaciones sistémicas inespecíficas o cuadros asintomáticos. En la literatura se han identificado el Carcinoma de Células Renales y el Tumor de Wilms como las masas renales más prevalentes en menores de 20 años, el Adenoma Metanéfrico es una entidad muy poco común en esa población. Presentación de caso Adolescente, con dolor en flanco izquierdo y hematuria macroscópica monosintomática, estudios imagenológicos evidencian lesión de aspecto neoplásico renal izquierda, que al complementarse con estudios de inmunohistoquímica resulta en Adenoma Metanéfrico. Se realiza revisión de literatura publicada en las últimas tres décadas al respecto. La paciente es llevada a nefrectomía radical izquierda, y posteriormente el estudio anatomopatológico sugiere Adenoma Metanéfrico, con marcadores de inmunohistoquímica que corroboran el hallazgo. Conclusiones Los tumores renales en adolescentes son raros. Se requiere de alta sospecha clínica, un examen físico meticuloso y el apoyo en imágenes diagnósticas. Generalmente, el estudio histopatológico determina el diagnóstico definitivo, no obstante, cuando persiste la confusión, se recurre a la inmunohistoquímica. El Carcinoma de Células Renales es el más prevalente de los tumores renales en adolescentes, pero existen entidades indistinguibles al estudio imagenológico que plantean un desafío clínico; es el objetivo brindar una herramienta de apoyo en el abordaje del Adenoma metanéfrico e instar al desarrollo de conocimiento sobre una entidad patológica en ese grupo etario que ha sido poco documentado que indudablemente redundará en mejores prácticas e impacto científico, social y económico.

Introduction Renal neoplasms in pediatrics and adolescents patients are rare entities, 6­7% masses in pediatrics. In teenagers, set a noteworthy clinical challenge. Can manifest as variable signs or be asymptomatic. In scientific papers, Renal Cell Carcinoma and Wilms' tumor have been identified as the most prevalent tumors in aged lesser than 20 years; Metanephric Adenoma is an unusual pathologic entity into this population. Case Report A female youngster case, with left flank pain and monosymptomatic macroscopic hematuria, imaging studies show up a neoplastic appearance lesion at left kidney, demonstrated as Metanephric Adenoma afterwards by immunohistochemistry analysis. Literature review is performed by searching in the last three decades. Patient was taken to left radical nephrectomy, later the pathological analysis suggests Metanephric Adenoma, and with immunohistochemistry markers is supported this finding. Conclusions Renal masses in adolescents are uncommon. It is needed high clinical suspicion, a thorough physical examination and imaging techniques aid. Conventionally, histopathology determine diagnosis, although in some cases when doubt last, it is necessary perform immunohistochemistry. Renal Cell Carcinoma is the most prevalent in youth's renal masses, but there are indistinguishable conditions on imaging that raise a defiant clinical scenario; it is the purpose to provide a clinical guidance tool in the approach of Metanephric adenoma and contribute to the development of knowledge in a scarcely documented clinicopathological entity that doubtlessly will reverberate in best clinical practice and echo at science, social and economics.

A Case of Renal Cortical Necrosis in a 15-year-old Boy with Acute Kidney Injury

Renal cortical necrosis (RCN) is patchy or diffuse ischemic destruction of the renal cortex caused by significantly reduced renal arterial perfusion. It is a rare cause of acute kidney injury (AKI) and is associated with high mortality. Here, we review the case of RCN in a 15-year-old boy who developed AKI. A 15-year-old boy was referred to our hospital from a local hospital due to a sharp decrease in his renal function. He presented with acute flank pain, nausea with vomiting, and oliguria for the past two days. He had taken a single dose of antihistamine for nasal congestion. At our hospital, his peak blood pressure was 148/83 mmHg and he had a high body mass index of 32.9 kg/m². The laboratory data showed a blood urea nitrogen (BUN) of 28.4 mg/dL, a creatinine of 4.26 mg/dL, and a glomerular filtration rate estimated from the serum cystatin C of 20.2 mL/min/1.73m². Proteinuria (spot urine protein to creatinine ratio 1.66) with pyuria was observed. Kidney sonography showed parenchymal swelling and increased renal echogenicity. Due to rapidly progressing nephritis, steroid pulse therapy (750 mg/IV) was done on the second day of his admission and the patient showed complete recovery with normal renal function. However, the kidney biopsy findings revealed renal cortical hemorrhagic necrosis. Multifocal, relatively well-circumscribed, hemorrhagic necrotic areas (about 25%) were detected in the tubulointerstitium. Although RCN is an unusual cause of AKI, especially in children, pediatricians should consider the possibility of RCN when evaluating patients with rapidly decreasing renal function.

Colonic Diffuse Large B-cell Lymphoma Hidden in Actinomycosis / 대한소화기학회지

Actinomycosis can mask malignant diseases. This paper reports a case of colonic diffuse large B-cell lymphoma (DLBCL), which was misdiagnosed as abdominal actinomycosis. A 76-year-old woman presented with right flank pain and weight loss. Abdominal CT and colonoscopy revealed a huge ascending colon mass. Despite the initial impression of a malignancy, a colonoscopic biopsy revealed no malignant cells, but sulfur granules and a filamentous organism suggesting actinomycosis. Intravenous penicillin G was administered under the impression of abdominal actinomycosis but her condition deteriorated rapidly. Follow up CT showed markedly increased colon mass and new multiple nodular lesions around the ascending colon. Sono-guided percutaneous biopsy of the nodular lesion was performed. The pathological result was DLBCL. The patient was scheduled to undergo chemotherapy but the patient expired due to cancer progression. The diagnosis of gastrointestinal infiltrating tumors is often difficult because a superficial biopsy usually does not provide a confirmative diagnosis. This case highlights the difficulty in making a correct diagnosis of lymphoma due to the concomitant actinomycosis. Malignant conditions must be considered in cases of actinomycosis with no response to antimicrobial therapy.

Posterior Nutcracker Syndrome with Microscopic Hematuria / 대한내과학회지

Nutcracker syndrome (NCS) refers to left renal vein compression with impaired blood outflow. The etiology of NCS has been attributed to various anatomic anomalies. Posterior NCS is caused by compression of the retroaortic left renal vein between the aorta and spine. The classic symptoms of NCS include left flank pain with gross or microscopic hematuria. The frequency and severity of the syndrome vary from asymptomatic microhematuria to severe pelvic congestion. For this reason, diagnosis of NCS is difficult and often delayed. Here, we report a case of posterior NCS that was incidentally discovered.

Colonic Diffuse Large B-cell Lymphoma Hidden in Actinomycosis / 대한소화기병학회잡지

Actinomycosis can mask malignant diseases. This paper reports a case of colonic diffuse large B-cell lymphoma (DLBCL), which was misdiagnosed as abdominal actinomycosis. A 76-year-old woman presented with right flank pain and weight loss. Abdominal CT and colonoscopy revealed a huge ascending colon mass. Despite the initial impression of a malignancy, a colonoscopic biopsy revealed no malignant cells, but sulfur granules and a filamentous organism suggesting actinomycosis. Intravenous penicillin G was administered under the impression of abdominal actinomycosis but her condition deteriorated rapidly. Follow up CT showed markedly increased colon mass and new multiple nodular lesions around the ascending colon. Sono-guided percutaneous biopsy of the nodular lesion was performed. The pathological result was DLBCL. The patient was scheduled to undergo chemotherapy but the patient expired due to cancer progression. The diagnosis of gastrointestinal infiltrating tumors is often difficult because a superficial biopsy usually does not provide a confirmative diagnosis. This case highlights the difficulty in making a correct diagnosis of lymphoma due to the concomitant actinomycosis. Malignant conditions must be considered in cases of actinomycosis with no response to antimicrobial therapy.

Clinical Significance of Urine Dipstick Positive for Albuminuria in Urolithiasis / 계명의대학술지

Urolithiasis is suspected by flank pain, costovertebral angle tenderness, and hematuria, and confirmed by computed tomography (CT). Treatment strategy and likelihood of spontaneous passage of a stone were determined by size and position of ureteral calculi and complication detected by CT. In general, the purpose of urinalysis for urolithiasis is to confirm the hematuria and pyuria. However, sometimes albumin is detected by urine dipstick test in urolithiasis. Therefore, I performed this study to investigate the clinical significance of urine dipstick positive for albuminuria in urolithiasis. This study was a retrospective review of medical records of 150 patients who visited the emergency department and diagnosed with urolithiasis by CT between March 2010 and February 2014. The patients were divided into a albuminuria group and non-albuminuria group. General chracteristics, clinical features, laboratory results, and CT findings were compared. The incidence of stones >5 mm in diameter, hydronephrosis (≥grade 2) and upper ureter stone were significantly higher in albuminuria group than non-albuminuria group. In multivariate logistic regression analysis, hydronephrosis (≥grade 2) and upper ureter stone were significantly associated with albuminuria. Upper ureter stone and hydronephrosis (≥grade 2) are also known as predictors for failure of spontaneous passage of ureter calculi. If further studies are done, urine dipstick positive for albumin in urolithiasis can be used as a predictor for failure of spontaneous passage of ureter calculi.

Failure of Ciprofloxacin Therapy in the Treatment of Community-Acquired Acute Pyelonephritis caused by In-Vitro Susceptible Escherichia coli Strain Producing CTX-Type Extended-Spectrum β-Lactamase

While carbapenems are the drug of choice to treat extended-spectrum-β-lactamase (ESBL)-producing strains, some alternative carbapenem-sparing regimens are suggested for antibiotic stewardship. We experienced a case of ciprofloxacin treatment failure for acute pyelonephritis caused by an apparently susceptible Escherichia coli. A 71-year-old woman presented the emergency department with fever for 7 days and bilateral flank pain for 2 days. The laboratory results and abdominopelvic computed tomography finding were compatible with acute pyelonephritis. During 3-day ciprofloxacin therapy, the patient remained febrile with persistent bacteremia. After the change in antibiotics to ertapenem, the patient’s clinical course started to improve. ESBL-producing E. coli isolates were identified in all three consecutive blood samples. Pulsed-field gel electrophoresis (PFGE) patterns, serotypes, and sequence types showed the three isolates were derived from the identical strain. The isolates produced CTX-M-14 type ESBL belonging to the ST69 clonal group. Despite in vitro susceptibility, the failure was attributed to a gyrA point mutation encoding Ser83Leu within quinolone resistance-determining regions. This case suggests that ciprofloxacin should be used cautiously in the treatment of serious infections caused by ciprofloxacin-susceptible, ESBL-producing E. coli, even in acute pyelonephritis because in-vitro susceptibility tests could fail to detect certain genetic mutations.

Failure of Ciprofloxacin Therapy in the Treatment of Community-Acquired Acute Pyelonephritis caused by In-Vitro Susceptible Escherichia coli Strain Producing CTX-Type Extended-Spectrum β-Lactamase

While carbapenems are the drug of choice to treat extended-spectrum-β-lactamase (ESBL)-producing strains, some alternative carbapenem-sparing regimens are suggested for antibiotic stewardship. We experienced a case of ciprofloxacin treatment failure for acute pyelonephritis caused by an apparently susceptible Escherichia coli. A 71-year-old woman presented the emergency department with fever for 7 days and bilateral flank pain for 2 days. The laboratory results and abdominopelvic computed tomography finding were compatible with acute pyelonephritis. During 3-day ciprofloxacin therapy, the patient remained febrile with persistent bacteremia. After the change in antibiotics to ertapenem, the patient’s clinical course started to improve. ESBL-producing E. coli isolates were identified in all three consecutive blood samples. Pulsed-field gel electrophoresis (PFGE) patterns, serotypes, and sequence types showed the three isolates were derived from the identical strain. The isolates produced CTX-M-14 type ESBL belonging to the ST69 clonal group. Despite in vitro susceptibility, the failure was attributed to a gyrA point mutation encoding Ser83Leu within quinolone resistance-determining regions. This case suggests that ciprofloxacin should be used cautiously in the treatment of serious infections caused by ciprofloxacin-susceptible, ESBL-producing E. coli, even in acute pyelonephritis because in-vitro susceptibility tests could fail to detect certain genetic mutations.

Ultrasonography of acute flank pain: a focus on renal stones and acute pyelonephritis

Ultrasonography is a useful tool for the differential diagnosis of acute flank pain. Renal stones appear as a focal area of echogenicity with acoustic shadowing on ultrasonography. In acute pyelonephritis (APN), the kidneys may be enlarged and have a hypoechoic parenchyma with loss of the normal corticomedullary junction. However, clinical and laboratory correlations are essential for the diagnosis of renal stones and APN through imaging studies. This review describes the typical ultrasonography features of renal stones and APN. Moreover, in daily practice, cross-sectional imaging is essential and widely used to confirm renal stones and APN and to differentiate them from other diseases causing flank pain. Other diseases causing acute flank pain are also described in this review.

A Case of Spontaneous Common Iliac Atery Dissection / 고신대학교의과대학학술지

Spontaneous and isolated dissection of the limb arteries without involvement of the aorta is extremely rare, and has been reported previously in pregnant patients in association with collagen vascular disease, and in cases of high-energy trauma or intensive activity in athletes. There is no consensus yet on indications for medical or surgical therapeutic modality. Due to the rarity of spontaneous dissection of external iliac artery, its natural history has been poorly described. A healthy 50-year-old male with normotension was admitted with an acute onset of left flank pain. Left external iliac artery dissection was diagnosed by abdominal computed tomography.

Bilateral Frosted Branch Angiitis in Kikuchi-Fujimoto Disease

PURPOSE: A case of frosted branch angiitis in Kikuchi-Fujimoto disease is reported. CASE SUMMARY: A 33-year-old male complained of a sudden decrease in visual acuity that developed in both eyes 5 days prior. He suffered from a headache, chills, myalgia, and flank pain 1 week before. The initial best-corrected visual acuity (BCVA) was 0.1 in the right eye and 0.2 in the left eye. On slit lamp examination, no inflammatory finding was observed in the anterior chamber and vitreous body of both eyes. On fundus examination, a diffuse vascular sheathing-like frosted branch was found in the retinal vessels, and retinal hemorrhage was observed. Fluorescein angiography showed staining and leakage of dye along the vascular sheathing. Serological findings were negative, showing no evidence of an autoimmune disease or viral infection. Neck ultrasonography revealed non-tender left cervical lymph node enlargement >1 cm in diameter. Ultrasound-guided fine needle aspiration cytology showed findings compatible with Kikuchi-Fujimoto disease, including necrotic changes and pronounced karyorrhexis, plus histiocyte and lymphocyte infiltration without neutrophils. We started systemic steroid therapy. One month after treatment, the BCVA of both eyes improved to 1.0. CONCLUSIONS: In patients with frosted branch angiitis, systemic disease such as Kikuchi-Fujimoto disease should be considered.

A Case of an Ureteropelvic Junction Obstruction Caused by a Crossing Vessel

Ureteropelvic junction obstruction is one of the common causes of hydronephrosis in infancy and childhood. Most cases of ureteropelvic junction obstruction are diagnosed prenatally and are usually asymptomatic. Although less common, older children can experience ureteropelvic junction obstruction that presents with symptoms including flank or abdominal pain. Here, we present the case of a nine-year-old healthy girl who had repeated flank pain and abdominal symptoms, with mild left hydronephrosis, for several months. Computed tomography that was performed during the period of acute flank pain revealed aggravated hydronephrosis on her left kidney, which was secondary to an ureteropelvic junction obstruction. She underwent laparoscopic pyeloplasty, and a crossing vessel that passed the ureteropelvic junction was identified. In addition, we reviewed the current literature of this rare entity.

Is STONE score a useful tool for limiting the use computed tomography in the patients suspected ureter stone? - A single-center retrospective study

OBJECTIVE: The STONE score was developed to gauge the ureter stone probability. On the other hand, it is unclear if the STONE score is also applicable to Koreans. This study evaluated whether the STONE score can identify patients with suspected nephrolithiasis for whom a computed tomography (CT) scan can be obtained in the emergency department, targeting Koreans. METHODS: Patients presenting to the emergency medicine (ED) with flank pain and a suspicion of a ureter stone between January 2016 and December 2016 were reviewed retrospectively. After calculating the STONE score, the enrolled patients were classified into the low, moderate, high score group. In each group, the prevalence of a ureter stone and other clinical diseases on a CT scan were investigated. RESULTS: Among the 156 patients included in the analysis, 124 (79.5%) had a ureter stone and an alternative diagnosis was made in 12 (7.7%). The prevalence of a ureter stone and alternative diseases in the high score group was 87.7% (71/81) and 4.9% (4/81), respectively. The proportion of patients with nephrolithiasis increased significantly (P < 0.001), but the proportion of patients with other clinical diseases did not decrease significantly across the score groups (P=0.196). The area under the receiver operating characteristic curve was 0.711 (95% confidence interval, 0.633–0.780; P=0.001) with a cut off score higher than 8 (sensitivity 82.3%, specificity 50.0%) for the STONE score. CONCLUSION: In this setting, the STONE score had a low specificity and could not accurately assess a ureter stone. More studies aimed at Koreans are warranted before a CT scan can be limited using the STONE score.

The burden of chronic ureteral stenting in cervical cancer survivors

ABSTRACT Purpose Ureteral obstruction in cervical cancer occurs in up to 11% of patients, many of whom undergo ureteral stenting. Our aim was to describe the patient burden of chronic ureteral stenting in a population-based cohort by detailing two objectives: (1) the frequency of repeat procedures for ureteral obstruction; and, (2) the frequency of urinary adverse effects (UAEs) (e.g., lower urinary tract symptoms, flank pain). Materials and Methods From SEER-Medicare, we identified 202 women who underwent ureteral stent placement prior to or following cervical cancer treatment. The frequency of repeat procedures and rate ratios were compared between treatment modalities. The rates and rate ratios of UAEs were compared between our primary cohort (stent + cervical cancer) and the following groups: no stent + cervical cancer, stent + no cancer, and no stent + no cancer. The “no cancer” group was drawn from the 5% Medicare sample. Results 117/202 women (58%) underwent >1 stent procedure. The frequency of additional procedures was significantly higher in patients who received radiation as part of their treatment. UAEs were very common in women with stent + cancer. The rate of UTI was 190 (per 100 person-years), 67 for LUTS, 42 for stones, and 6 for flank pain. These rates were 3-10 fold higher than in the no stent + no cancer control group; rates were also higher than in the no stent + cancer and the stent + no cancer women. Conclusions The burden of disease associated with ureteral stents is higher than expected and urologists should be actively involved in stent management, screening for associated symptoms and offering definitive reconstruction when appropriate.

Late-Developing Metastatic Malignant Melanoma in the Thoracic Spine Originating from Choroidal Melanoma

A 54-year-old woman visited Gangnam Severance Hospital for left side flank pain. She had a history of total removal of malignant melanoma on the left eye ball 20 years prior. No evaluation had been performed since then. A paravertebral mass at thoracic ninth level (T9) was discovered on spinal magnetic resonance imaging, and pathology confirmed malignant melanoma. Following positron emission tomography-computed tomography, no other metastasis was discovered. After removal of the paravertebral mass, palliative chemotherapy (dacabarzine + tamoxifene) was administered in 3 cycles over 2 months. Radiotherapy with simultaneous integrated boost technique was performed at 4,350 cGy total over 15 days, 290 cGy per delivery, and was administered with the first cycle of palliative chemotherapy. Despite this treatment, multiple metastases developed throughout her body 7 months later, and the patient is continuing chemotherapy.

Collecting Duct Carcinoma (Bellini Duct Carcinoma) Presented as a Renal Cyst

Renal cysts are frequently seen in the general population. Most small simple renal cysts are managed by conservative treatment. A renal cell carcinoma (RCC) presenting as a renal cyst is extremely uncommon, and collecting duct carcinoma is a rare type of RCC. This report describes a collecting duct carcinoma initially presnted as a renal cyst. The patient was a 52-year-old man who had been diagnosed with a renal cyst in the left lower pole 8 years earlier but was not regularly follow-up. He presented with left flank pain and gross hematuria. Computed tomography revealed a heterogeneous enhanced mass in the left lower pole and multiple para-aortic lymph nodes. He underwent radical nephrectomy and lymph nodes dissection which confirmed collecting duct carcinoma with sarcomatoid differentiation.

Spontaneous ruptured pheochromocytoma: an unusual case report and literature review

Ruptured pheochromocytoma is a rare disease. Its mortality rate is up to 31%–50%. Proper management of ruptured pheochromocytoma remains unclear. A 44-year-old male patient visited our Emergency Department and presented with abrupt onset of left flank pain. His blood pressure was 190/140 mmHg with purse rate of 130 beats/min. CT scan showed 8.1 × 5.6-cm-sized heterogeneously mass with rupture on the left retroperitoneal space and active bleeding. His symptom of abdominal pain was aggravated. Follow-up laboratory analysis revealed elevated WBC count and decreased hemoglobin 2 hours after admission. Emergency laparotomy was performed. We resected the ruptured left retroperitoneal mass and hemostasis. Pathologic exams revealed adrenal pheochromocytoma with rupture. Although our patient was alive, according to literature review, mortality rate of emergency operation without medical management is higher than elective operation after blood pressure control with either medical or interventional methods such as transcatheter arterial embolization.

Clinical Characteristics of Febrile UTI First Developed Over 5 Years of Age

PURPOSE: Febrile urinary tract infection (UTI) is one of the commonest bacterial infections in children. The purpose of this study is to investigate the clinical characteristics of the first episode of febrile UTI occurring in children over 5 years compared to those in infants younger than a year. METHODS: We retrospectively reviewed the medical records of 10 patients over 5 years, having febrile UTI, and 25 controls under 1 year. Clinical characteristics including symptoms at admission, the time interval between symptom onset and hospital visit and/or diagnosis, duration of fever, urinalysis, and other laboratory and imaging test results were compared between the two groups. RESULTS: Most patients in the control group showed only high fever at the time of presentation to the hospital. However, 60% of the case group had fever along with gastrointestinal (GI) symptoms such as abdominal and flank pain, vomiting, as well as relatively mild pyuria. The case group showed a longer duration between symptom onset and hospital visit and/or diagnosis. CONCLUSIONS: Delay in diagnosis and initiation of treatment of UTI increases the risk of permanent renal scarring and associated complications. Therefore, early diagnosis and treatment of febrile UTI is vital for very young infants, as well as children considering that febrile UTI could be an important cause of febrile illness in children over 5 years.

Usefulness of Blood Cultures and Radiologic Imaging Studies in the Management of Patients with Community-Acquired Acute Pyelonephritis

BACKGROUND: The objective of this study was to examine the usefulness of blood cultures and radiologic imaging studies for developing therapeutic strategies in community-acquired acute pyelonephritis (CA-APN) patients. MATERIALS AND METHODS: We prospectively collected the clinical data of CA-APN patients who visited 11 hospitals from March 2010 to February 2011. RESULTS: Positive urine and blood cultures were obtained in 69.3% (568/820) and 42.7% (277/648), respectively, of a total of 827 CA-APN patients. Blood culture identified the urinary pathogen in 60 of 645 (9.3%) patients for whom both urine and blood cultures were performed; the organisms isolated from urine were inconsistent with those from blood in 11 and only blood cultures were positive in 49 patients. Final clinical failure was more common in the bacteremic patients than the non-bacteremic ones (8.0% vs. 2.7%, P = 0.003), as was hospital mortality (3.6% vs. 0.3%, P = 0.003). Likewise, durations of hospitalization and fever were significantly longer. Bacteremia was independent risk factor for mortality (OR 9.290, 1.145-75.392, P = 0.037). With regard to radiologic studies, the detection rate of APN was 84.4% (445/527) by abdominal computed tomography and 40% (72/180) by abdominal ultrasonography. Eighty-one of 683 patients (11.9%) were found to have renal abscess, perinephric abscess, urolithiasis, hydronephorosis/hydroureter or emphysematous cystitis, which could potentially impact on clinical management. Patients with Pitt score ≥ 1, flank pain or azotemia were significantly more likely to have such structural abnormalities. CONCLUSION: Blood cultures are clinically useful for diagnosis of CA-APN, and bacteremia is predictive factor for hospital mortality. Early radiologic imaging studies should be considered for CA-APN patients with Pitt scores ≥1, flank pain or azotemia.

Acute renal infarction secondary to membranous glomerulopathy

BACKGROUND: Acute renal infarction often presents with abdominal  pain,  nausea,  vomiting,  and  fever.With other more common illnesses presenting with the same symptoms, it is often misdiagnosed leading to delayed treatment.We present a case of a young female diagnosed to have Membranous Glomerulopathy who presented with sudden onset  flank  pain  in  whom was initially treated as urinary tract infection. CASE: A  19-year-old  female  diagnosed  with  membranous glomerulopathy presented at the Emergency Room (ER) with severe,  right  sided,  flank  pain  of  acute  onset,  associated with nausea and vomiting. No fever, dysuria, hematuria, or history of trauma. Her vital signs were within normal range. Abdominal  examination  revealed  a  distended  but  soft non-tender  abdomen  with  positive  shifting  dullness and fluid wave test. Right sided costovertebral angle tenderness was  elicited.Initial diagnostics showed leukocytosis with neutrophilic  predominance,  serum  creatinine  of  0.77mg/dL,  and  proteinuria  of  >600mg/dL.Abdominal  ultrasound showed  non-specific  findings,  thus  contrast-enhanced  computed  tomography  scan  (CT-Scan)  of  the  abdomen was  done which revealed areas of non-enhancement in the upper to middle portions of the right kidney which may relate to areas of ischemia and/or infarction, likely due to thrombosis involving the more distal portion of the right renal artery and massive ascites. Result was confirmed by computed tomography angiography (CTA) of the kidneys showing right renal artery thrombosis. Evaluations for other causes  of  renal  artery  thrombosis  aside  from  patient's concurrent  membranous  glomerulopathy  were  done  and were negative. Anti-coagulation therapy was initiated using low molecular weight heparin (LMWH) and was thereafter maintained on warfarin.CONCLUSION: A  high  index  of  clinical  suspicion  is  needed to  diagnose  acute  renal  infarction  because  of  its  non-specific symptoms which can mimic other conditions. Early diagnosis and prompt initiation of anti-coagulation therapy is  important  to  avoid  irreversible  kidney  damage.  Acute renal infarction should be considered as a cause of acute onset flank pain in patients with risk factors and normal initial screening test.