[Renal inflammatory pseudotumor manifesting as a prolonged fever]

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.

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.

[Prolonged fever: specific issues in the young adult population]

Early studies on prolonged fever date back to the 1960s. Fifty years later, prolonged unexplained fever remains a diagnostic challenge to the general internists. Although the aetiologies of prolonged fevers have not changed much in the general population, the distribution between the various causes is not the same anymore. A regular decrease in infectious and neoplastic causes is noticed whatever the age. Prolonged fevers related to inflammatory disorders and fevers that remain of unknown origin still represent approximately 30 to 50% of the cases. In the young adult population, as in the older patients, prolonged fevers can be attributed to four groups: infection, inflammation, neoplasic and other aetiologies (including drug-related fevers). In the young adult population, the management of prolonged fever presents some specific issues that are the purpose of this review coupled with our own experience. The prognosis of undiagnosed prolonged fever is usually favourable, as a life-threatening aetiology is exceptionally diagnosed during the follow-up if the initial management was complete and accurate.

Inflammatory pseudotumor of the kidney with renal artery penetration

Inflammatory pseudotumor (IPT) is a quasineoplastic lesion that most commonly involves the lung and the orbit; kidney involvement is rare. We report a case of inflammatory pseudotumor of the kidney. The patient was a 61-year-old man who presented with no symptoms. Nonenhanced computed tomography (CT) demonstrated an ill-defined, isodensity mass measuring 3.5 cm in the lower portion of the left kidney. Contrast-enhanced CT showed that branches of the renal artery without encasement penetrated the tumor; there was a little enhancement in the mass on the arterial phase and homogeneous enhancement on the venous phase. On magnetic resonance imaging the mass showed intermediate signal intensity on T1-weighted images (T1WIs) and low signal intensity on T2WIs. Most IPTs of the kidney appear as an ill-defined, hypovascular, homogeneous tumor on CT images, with variable signal intensity on MRI T1WIs and low signal intensity on T2WIs. Our case had the same imaging findings, with branches of the renal artery penetrating the tumor. If the renal tumor has these radiological findings, the tumor may be IPT.

Inflammatory myofibroblastic tumor of the kidney in a child: report of a case

Inflammatory myofibroblastic tumor (IMT), also known as inflammatory pseudotumor, is an uncommon benign tumor that has been reported in various locations throughout the body, but rarely in the kidney. To our knowledge, only 22 cases of renal IMT have been described in the literature. Renal IMT in children is difficult to differentiate from a malignancy such as Wilms' tumor. We report a case of a 9-year old girl with a left renal mass mimicking malignancy on preoperative diagnostic images, which was pathologically revealed to be an IMT. We review the literature and discuss the pathophysiology and clinical features of this unusual tumor.

[Inflammatory pseudotumor of the kidney: about a case of bilharzioma]

Inflammatory pseudotumors are benign neoplasms associated with local or general manifestations. Renal localisation seems exceptional, the etiology is unknown. The article raises the question of the problem in establishing a preoperative definitive diagnosis, as a correct diagnosis is often only confirmed following nephrectomy.

Intrarenal solitary fibrous tumor of the kidney report of a case with emphasis on the differential diagnosis in the wide spectrum of monomorphous spindle cell tumors of the kidney

Solitary fibrous tumor (SFT) is a neoplasm that can occur in the urogenital tract, and is also reported occurring in the spermatic cord, seminal vesicles, urinary bladder, prostate, and kidney. Furthermore, it is most important to consider its existence in the kidney, because it is usually diagnosed as renal cell carcinoma pre-operatively. To our knowledge, only 10 cases of SFT have been reported in the kidney to date. We report the clinico-pathological features of an intrarenal SFT occurring in a 31-year-old woman. The tumor, measuring 8.6 cm in its greatest diameter, completely replaced the cortex and the medulla of the middle region of the right kidney, compressing the pelvis. Radiological imaging was consistent with a renal cell carcinoma. Histologically, the tumor was composed of a proliferation of bland-looking vimentin+, CD34+, bcl2+ and CD99+ spindle cells exhibiting a haphazard to storiform growth pattern, pushing borders, and a low mitotic rate (2 mitoses x 10 HPF). We placed emphasis on the differential diagnostic problems, i.e., its differentiation from other primary monomorphous benign and malignant spindle cell tumors of the kidney, such as fibroma, benign fibrous histiocytoma, hemangiopericytoma, inflammatory myofibroblastic (pseudo-)tumor, leiomyoma, angiomyolipoma with predominant spindle cell smooth muscle component, benign peripheral nerve sheath tumors, renal mixed epithelial/stromal tumors, adult type mesoblastic nephroma, fibrous type monophasic synovial sarcoma, malignant peripheral nerve sheath tumors, fibrosarcoma, and low-grade fibromyxoid sarcoma.