Inflammatory myofibroblastic tumor (IMT) is a rare entity that most commonly involves the lung. However, an IMT of the kidney is extremely rare. The etiology and pathogenesis of IMT remain unknown. The present study describes the case of a 48-year-old female who presented asymptomatically. Imaging investigations revealed a mass in the left kidney and a pathological examination of the nephrectomy specimen revealed an IMT. The patient had a history of trauma in the left hypochondrium 13 years previously and a history of hepatitis B for 20 years. The latter developed into hepatic cirrhosis, hypersplenism and coagulation disorders, which may play have played a significant role in the development of the IMT of the kidney in the present case and also may aid in improving the understanding of the etiology and pathogenesis of IMT of the kidney.

Abstract. Renal oncocytoma is one of the most unusual benign lesion, which are usually diagnosed postoperatively, since their differentiation from renal cell carcinoma is challenging. The present study reports two cases of renal oncocytoma in a 60-year-old woman and a 46-year-old man. Relevant clinical and pathological data on the two patients were retrieved. The tumors were excised and the patients underwent laparoscopic radical nephrectomy. Typical features of oncocytoma were observed upon histological examination of the excised specimens. The postoperative course of each patient was uneventful and they were discharged 8 and 7 days post-surgery, respectively. In addition, the current study presents the results of a literature review regarding the radiological, immunohistochemical and pathological characteristics of renal oncocytoma. IntroductionRenal oncocytoma is an uncommon tumor of the renal parenchyma, accounting for ~4.3% of all solid renal masses (1). It is composed of oncocytes, which are uniform, round or polygonal neoplastic cells that exhibit a granular eosinophilic cytoplasm (2). Despite certain manifestations of malignancy, the majority of oncocytomas are considered to have a benign behavior, with only a few reported cases of metastasis (3). Based on morphological, histochemical and pathological features, it is usually possible to distinguish renal oncocytoma from other types of renal neoplasms; however, in certain cases, overlapping phenotypes may pose a challenge in the differential diagnosis of the disease (4). Renal oncocytoma usually has a benign clinical course with excellent long-term outcomes; it has been previously reported that disease-specific survival is 100% The present study reports two cases of renal oncocytoma that were successfully treated with laparoscopy. The clinical, radiographical and pathological findings of the two cases are discussed in the present study. Case reportCase 1. A 60-year-old female patient presented to The First Hospital of Jilin University (Changchun, China) in March 2012 with a tumor in the right kidney, which was incidentally observed by imaging modalities during a physical workup at our hospital. The patient denied any history of hematuria, fever, weight loss or other constitutional symptoms, but had a medical history of hypertension and coronary heart disease. Physical examination and laboratory test results were unremarkable. Abdominal ultrasonography demonstrated an ~4.5x5.3-cm solid, relatively well-demarcated mass occupying the right kidney. Computed tomography (CT; LightSpeed VCT; GE Healthcare Bio-Sciences, Pittsburgh, PA, USA) revealed a 5.4x4.8 cm, heterogeneous and markedly enhancing mass in the right kidney (Fig. 1). Chest X-ray, chest CT and bone scans were all negative for metastasis. Based on the radiological findings, laparoscopic radical resection of the right kidney was performed to remove the tumor.Macroscopic examination of the 12.0x6.0x4.5 cm nephrectomy specimen revealed a 6.5x4.5x4.0 cm quasi-circular mass in the middle of the right ki...

Carcinosarcoma is a rare type of renal pelvis malignancy, the diagnosis of which requires the presence of malignant epithelial and mesenchymal components. The prognosis of this disease is extremely poor due to its rapid progression and widespread metastases. The present study describes a case of carcinosarcoma involving the right renal pelvis in a 73-year-old female who presented with intermittent hematuria and right-flank pain that had persisted for one month. Computed tomography revealed a 2.4×2.5 cm mass in the right renal pelvis, which was diagnosed as a right renal pelvic tumor. Laparoscopic radical resection of the right kidney and ureter was performed. Following surgery, immunohistochemical analysis showed positive reactions for epithelial and mesenchymal markers. Based on these findings, the patient was diagnosed with carcinosarcoma. Thus, immunohistochemical analysis is a critical method for the accurate diagnosis of carcinosarcoma.

A solitary fibrous tumour (SFT) is a rare mesenchymal cell neoplasm that can develop at any site. SFT of the kidney is extremely rare. Recently, we had a case of solitary fibrous tumour involving the left kidney in a 71-year-old female patient. The SFT was incidentally found by imaging modalities at the time of a physical workup. Computed tomography and retrograde pyelography showed a 4 × 3.5 × 4-cm nodular mass in the middle poles of the left kidney adjacent to the renal pelvis. A laparoscopic radical resection of the left kidney was performed. The tumour was well-circumscribed and composed of a mixture of spindle cells; microscopically, we found dense collagenous bands. Immunohistochemical studies showed strong reactions with CD34, bcl-2 and CD99. A nuclear positivity with Ki-67 was observed in less than 1% of cells. The tumour was negative for desmin, SMA and CD117. Histopathological and immunohistochemical studies confirmed the diagnosis of a solitary fibrous tumour.