Inflammatory pseudotumor of the kidney with renal artery penetration

The MRI features of renal inflammatory pseudotumor: A case report and literature review

RATIONALE

Inflammatory pseudotumor is rare observed in renal immunoglobulin G4-related disease.

PATIENT CONCERNS

A 65-year-old female presented with a mass in the right kidney which was found in physical examination.

DIAGNOSES

Based on the imaging findings and clinical manifestations, we preliminarily judged that the mass of the right kidney was renal cell carcinoma.

INTERVENTIONS

The patient finally underwent total nephrectomy.

OUTCOMES

The final result of microscopic pathological examination is renal inflammatory pseudotumor.

LESSONS

There are some characteristics on magnetic resonance imaging of renal inflammatory pseudotumor, which can improve diagnosis rate by combining with medical history and clinical manifestations.

Inflammatory Pseudotumor of the Renal Pelvis

Background: Inflammatory pseudotumor of the kidney is a rare disease of unknown etiology. There are no specific clinical or radiologic findings. The lesion can mimic renal cell carcinoma or transitional cell carcinoma depending on the site of involvement. These tumors, if diagnosed correctly, may respond to medical management. We present a case in which an inflammatory pseudotumor of the renal pelvis was misdiagnosed as a transitional cell carcinoma and unwarranted surgical intervention was performed. Case Presentation: A 39-year-old man presented with left flank pain and gross hematuria. On MRI, there was a hypointense 2.4 × 1.8 cm lesion involving the left renal pelvis. The urine cytology and biopsy of the lesion were inconclusive. On follow-up cans the lesion increased in size and patient had repeated hematuria. The lesion was clinically presumed to be a transitional cell carcinoma of the left renal pelvis. A laparoscopic left side nephroureterectomy along with bladder cuff excision and para-aortic lymphadenectomy was performed. The histology report revealed the lesion to be inflammatory pseudotumor of the renal pelvis. Conclusion: Inflammatory pseudotumor should always be considered in differential diagnosis of pelvic tumors, especially when image findings and biopsies are inconclusive.

Rare presentation of inflammatory myofibroblastic tumor in the kidney

Inflammatory myofibroblastic tumor (IMT) is a rare pathologic entity that has been mostly described in the lung. It has been reported in nearly every organ, with occurrence in the kidney being extremely rare. IMT has nonspecific clinical and radiological findings and often mimics a malignant process. This is a case discussing the radiologic and pathologic findings of a renal IMT in a 35-year-old female who underwent radical nephrectomy for a right renal pelvis mass that was mistaken for transitional cell carcinoma.

Inflammatory Myofibroblastic Tumor of the Urinary System on Computed Tomography at a High-Volume Institution in China

OBJECTIVE

Inflammatory myofibroblastic tumors (IMTs) of the urinary system are relatively rare and often misdiagnosed. We aimed to summarize and analyze the clinical manifestations, imaging features, management, and follow-up of renal and bladder IMTs.

METHODS

In this retrospective study, 22 patients with IMT pathologically verified between 2009 and 2018 were included. Epidemiologic, clinical, pathologic, and imaging findings were recorded. Tumor size, location, and shape were analyzed and summarized.

RESULTS

There were 22 patients with a median age of 45 years (range: 20-74), including 14 patients with renal IMT and 8 patients with bladder IMT, who met the eligibility criteria. In 21 patients, IMT appeared as a single lesion, whereas 1 patient showed bilateral renal lesions. Surgical resection was the sole therapy, and follow-up information was acquired from 13 individuals with no evidence of recurrence or metastasis. In our study, a slightly hypodense or isodense homogeneous tumor with a clear boundary was more often seen. On contrast-enhanced computed tomography (CT), they were often manifesting as a slightly heterogeneous enhancement.

CONCLUSIONS

The nature of IMTs might cause a lack of generalizability. However, it will be useful to know that there are various CT demonstrations of IMTs. CT images are useful for the detection, location, and characterization of urinary IMTs, which can help in better clinical decision-making and can also be an optimal imaging technique for follow-up.

Kidney inflammatory myofibroblastic tumor masquerading as metastatic malignancy: A case report and literature review

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal tumor that is characterized by spindle cells differentiated from muscle fibroblasts and infiltration of various types of inflammatory cells. IMT can occur at any age and at any anatomic site. The most common location of IMT is the bladder in the genitourinary tract. Only scarce cases of kidney IMT have been reported in the literature.

CASE SUMMARY

A 77-year-old woman, with a history of bilateral renal calculus for 15 years, was admitted to the Department of Urology of our hospital complaining of recurrent painless gross hematuria for one month. The treatment with cephalosporin was ineffective. Computed tomography imaging showed a mixed density and slightly heterogeneously enhanced lesion in the middle pole of the left kidney and ipsilateral adrenal enlargement. The patient underwent surgical treatment by retroperitoneoscopic left radical nephrectomy plus adrenalectomy. A large number of typical spindle cells surrounded by plasma cells and lymphocytes were observed microscopically. Immunohistochemical analyses indicated that these spindle cells were positive for vimentin, cytokeratin (CK), Ki-67, CK7, CD34, and CD31 and were focally positive for CD10 and anaplastic lymphoma kinase (ALK-1). Thus, a diagnosis of IMT was made definitively. The patient recovered well after operation, and no recurrence or metastasis was noted during the 22-mo follow-up.

CONCLUSION

Since kidney IMT is very rare and lacks characteristic clinical manifestation, it is easily misdiagnosed as a malignant tumor before operation. Surgery remains the best choice for diagnosis and treatment, and such cases must be followed carefully because of the uncertain biological behavior of this tumor. This report suggests that renal calculus may be one of the causes of IMT, but further investigation is necessary to prove it.

Inflammatory myofibroblastic tumor of kidney together with ipsilateral perinephric and periureteric fibrosis: A case report and literature review

RATIONALE

Both inflammatory myofibroblastic tumor (IMT) and retroperitoneal fibrosis are rare lesions, but kidney involvement is more rare. It is the first study about IMT of the kidney in a patient with perinephric and periureteric fibrosis and we hold that fibroblast proliferation may be an intermediate status in oncogenesis of IMT. But further investigation is necessary in order to better clarify the relationship between fibroblast proliferation and IMT.

PATIENT CONCERNS

A 54-year-old female presented no positive signs except dull back pain after overwork.

DIAGNOSES

On the basis of the urinary ultrasonography and computed tomography (CT) scan, we strongly suspected a renal cell carcinoma.

INTERVENTIONS

Considering the little remaining function of the right kidney and the possibility of malignancy, we performed a laparoscopic right radical nephrectomy.

OUTCOMES

According to the analysis of the postoperative paraffin section and immunohistochemistry assay, a final diagnosis of IMT and retroperitoneal fibrosis nodules was made.

LESSONS

Both IMTs are rare lesions and its etiology and pathogeny are unclear. It is the first study about IMT of the kidney in a patient with perinephric and periureteric fibrosis. This report suggested that fibroblast proliferation may be an intermediate status in oncogenesis of IMT, but further investigation is necessary in order to better clarify the relationship between fibroblast proliferation and IMT. The preoperative diagnosis of renal IMT remains difficult. Preoperative fine-needle aspiration or percutaneous biopsy and intraoperative frozen section were applied to confirm the diagnosis to avoid unnecessary nephrectomy, especially in patients with renal insufficiency, bilateral masses, or a solitary kidney.

CT Manifestations of Inflammatory Myofibroblastic Tumors (Inflammatory Pseudotumors) of the Urinary System

OBJECTIVE

The purpose of this study is to characterize the CT manifestations of inflammatory myofibroblastic tumors (IMTs) of the urinary system in eight patients.

MATERIALS AND METHODS

The CT images of eight pathologically confirmed IMTs were retrospectively reviewed. Two of the eight IMTs occurred in the kidney, and six occurred in the bladder. Seven patients underwent both unenhanced CT and contrast-enhanced CT, and one of the patients who had a bladder tumor underwent unenhanced CT only. The site, shape, size, boundary, internal structure, and enhancement pattern of the lesions were assessed.

RESULTS

The eight patients (five men and three women) whose CT images were reviewed were 18-77 years old (mean age, 53 years). Only one lesion was seen in each of the eight patients. The IMTs occurred at the renal parenchyma (n = 1), the renal pelvis (n = 1), or the bladder (n = 6). Their shape was either roundlike (n = 7) or round (n = 1), and their size ranged from 1.5 × 2.0 cm(2) to 3.7 × 5.2 cm(2). Tumor margins were smooth (n = 5) or lobulated (n = 3), and boundaries were clear (n = 5) or ill defined (n = 3). Unenhanced CT scans showed a low density (n = 4), isodensity (n = 3), or a slightly high density (n = 1). The density noted on the unenhanced CT scans was homogeneous (n = 7) or heterogeneous (n = 1). The contrast-enhanced scans showed ring enhancement (n = 3) or significantly heterogeneous enhancement (n = 4), and the type of enhancement was persistent (n = 6) or washout (n = 1).

CONCLUSION

IMTs in the urinary system commonly occur in the superior wall or the front wall of the bladder. The observation that polypoid nodules on the bladder walls show ring enhancement on contrast-enhanced CT may be valuable in the diagnostic imaging of IMTs of the urinary system.

Inflammatory Myofibroblastic Tumor of the Kidney and Bilateral Lung Nodules in a Child Mimicking Wilms Tumor With Lung Metastases

Renal inflammatory myofibroblastic tumor (IMT) is an extremely rare lesion especially in children. This report describes a case of renal IMT accompanied by multiple lung nodules mimicking Wilms tumor with lung metastasis in a 3-year-old boy. To our knowledge, this is a unique case of IMT which has not been reported in the literature previously.

A Renal Inflammatory Myofibroblastic Tumor Similar to Cystic Renal Cell Carcinoma: One Case Report

We describe and analyze the clinical course and imaging findings of a case of a renal inflammatory myofibroblastic tumor (IMT) that is similar to cystic renal cell carcinoma. "Solitary cysts" on the left kidney were found during a health examination of a 60-year-old female. The patient also had hypertension. She had undergone surgeries twice for limb trauma fracture and had no definite record of hepatitis. There was no tenderness with percussion of the kidney area or edema in the lower extremity. The renal function results, including serum creatinine, blood urea nitrogen, and blood urea, were within the normal range. No gross hematuria or microscopic hematuria was found. An 8.7  cm × 9.2  cm mixed echogenic mass at the upper pole of the left kidney was observed with ultrasound, the majority of which was an anechoic mass that was slightly protruding from the renal capsule and had well-circumscribed borders. After a bolus injection of an ultrasound contrast agent, the mass had rapid enhancement with fast fading. An approximately 9.4  cm × 10.1  cm round-like cyst lesion at the upper pole of the left kidney was revealed by computed tomography (CT) examination of the abdomen; it had edge finishing with well-circumscribed borders. The upper inner wall of the lesion was thick with crescentic soft tissue. The solid content had gradual enhancement on enhanced CT scans. A kidney tumor was considered based on the CT findings. Based on the preoperative examination, the left renal cystic masses were resected. Intraoperative frozen sections were used to further clarify the nature of the lesion, and no significant malignant cells were observed; therefore, the kidney was not removed. The pathological diagnosis was renal IMT. After surgery, the patient recovered and did not have recurrence or metastasis over the course of long-term follow-up. CT images of our patient with renal cystic disease are categorized as Fuhrman grade IV and typically indicate the presence of malignant lesions. However, gradual enhancement of the solid content in our case is different from typical cystic renal cell carcinoma. The nature of the lesion was further identified using intraoperative frozen sections, which helped avoid unnecessary nephrectomy.

Inflammatory pseudotumor of the kidney

Inflammatory pseudotumor of the kidney is a rare benign condition with unknown etiology that can mimic malignancy. We report a case of inflammatory pseudotumor of the kidney. A 59-year-old male patient was admitted with a complaint of right flank pain and hematuria. Ultrasonography and magnetic resonance imaging of the patient revealed a 9 cm × 10 cm mass originating from the renal parenchyma with posterior extension. Operative findings revealed a mass adhering to the psoas muscle. Histopathologic examination demonstrated spindle-shaped fibroblast cells accompanying inflammatory cells. The pathological diagnosis was renal inflammatory pseudotumor. Repeated US and computed tomography revealed complete remission.

Bilateral renal inflammatory pseudotumour effectively treated with corticosteroid

Inflammatory pseudotumour (IPT) is a rare disease of unknown cause that most commonly involves the lung but can occur in almost any site in the body. Occurrence in the kidneys is very rare and bilateral renal involvement even rarer. There are 34 previously reported cases in the English-language medical literature between 1966 and 2008. Herein we report a case of IPT infiltrating both kidneys. We have also reviewed the clinical features, radiological findings, treatment and outcome of renal IPT. Clinical features at presentation are commonly non-specific. Features on imaging are inadequate to make a diagnosis of IPT or to clearly distinguish it from malignancy. Consequently diagnosis has frequently been made after nephrectomy and on a few occasions with the aid of percutaneous or open biopsies. The majority of renal IPT (83%) have been treated with nephrectomy and those cases with bilateral IPT have received corticosteroids.