Inflammatory pseudotumor of the kidney: report of a case

We report a case of inflammatory pseudotumor of the kidney. A 73-year-old man presenting with general malaise and minimal grade fever visited a medical department in our hospital. Computerized tomography incidentally revealed a tumor, 3.5 cm in diameter, in the lower pole of the left kidney, and he was referred to our outpatient department. Selective left renal arteriography disclosed an avascular mass on the affected site. Left radical nephrectomy was performed under the diagnosis of avascular renal cell carcinoma. Histological examination demonstrated a tumor composed of spindle-shaped fibroblastic cells infiltrated by variable numbers of plasma cells, small lymphocytes and histiocytes. The pathologic diagnosis was renal inflammatory pseudotumor. Fourteen previously reported cases of this tumor have reviewed in the literature.     

Renal inflammatory pseudotumor after embolization for arteriovenous malformation: a case report

A 61-year-old man was admitted to our hospital with the chief complaint of asymptomatic macrohematuria. Because he was diagnosed with arteriovenous malformation of the right kidney by angiography, embolization was performed. However, 2 years and 3 months later, bleeding from the right kidney was detected. Computed tomography (CT) revealed a low density area (1.8 cm) in the right kidney protruding to the renal pelvic adjacent to the old embolized lesion. Since we could not make a conclusive diagnosis as malignant disease by ureteroscopy and angiography, we have decided to follow the case carefully. Nine months later, macroscopic hematuria worsened, and the low density area by CT in the right kidney expanded. Therefore, we finally decided to perform right total nephroureterectomy. The tumor was histologically diagnosed as renal inflammatory pseudotumor. This is the 14th case reported in Japan. We here report the renal inflammatory pseudotumor with a review of the Japanese literature.     

Inflammatory pseudotumor of the kidney: A case report

Inflammatory pseudotumor of the kidney is a very rare lesion. We report a patient who had a renal mass raising the suspicion of a malignant neoplasm and the pathologic examination revealed an inflammatory pseudotumor. Despite its rarity, inflammatory pseudotumor of kidney should be kept in mind in the differential diagnosis of a solitary renal mass.     

A case of inflammatory pseudotumor of renal pelvis showing a complete response to antibiotics

A 20-year-old woman was admitted with chief complaints of high fever and right lumbago. Abdominal computed tomography (CT) and ultrasonography revealed a right renal pelvic tumor 25 mm in diameter. Although malignancy could not be confirmed by the scan, we administered antibiotics based on a diagnosis of inflammatory pseudotumor of the renal pelvis. After treatment, no tumor was detected. In such cases,because diagnosis is generally difficult, surgery is usually performed. However, in this case, the patient showed a complete response to antibiotics.     

Pulmonary inflammatory pseudotumor with rapid growth and serum carcinoembryonic antigen elevation

Inflammatory pseudotumors consist of chronic inflammatory cells, predominantly plasma cells. We report a rare case of pulmonary inflammatory pseudotumor associated with rapid growth and elevated serum carcinoembryonic antigen (CEA). A 75-year-old man referred for bloody sputum was found in chest computed tomography (CT) to have a round circumscribed tumor with a cavity located in the periphery of the right lower pulmonary lobe. Cytological examination of a biopsy specimen obtained by CT-guided transthoracic fine needle aspiration showed no malignancy. Two months later, the tumor had noticeably grown, accompanied by a notable rise in serum CEA. We conducted right lower pulmonary lobectomy with regional lymph node dissection, since malignancy could not be ruled out by frozen-section examination. Histological examination of the resected specimen showed an inflammatory pseudotumor with CEA production.     

Inflammatory pseudotumors of the kidney: a case report

Inflammatory pseudotumors are uncommon benign tumors of unknown etiology which may develop at several anatomical sites, e.g., the airways and gastrointestinal tissues, soft tissues, the orbit, the spleen, or the lymph nodes. The renal site is extremely rare, and presents the problem of differential diagnosis as the clinical and radiological aspects of this tumor are similar to those of an adenoma or an angiomyolipoma, and suggest the presence of a carcinoma, in particular a cystic renal carcinoma which is also a rare form of tumor. There is therefore a risk that this benign lesion could be misdiagnosed. Due to the good prognosis associated with this type of tumor, in cases where the definitive diagnosis has been established no surgical procedure is necessary. However, the difficulty in making this diagnosis preoperatively means that in general the organ has to be surgically removed so that a histological analysis can be made and the negative or positive findings confirmed. In the present study, the case of an inflammatory pseudotumor of the kidney has been described. In this instance, radical nephrectomy of the left kidney was carried out as the disease was presumed to be renal cell adenocarcinoma. However, the histopathological analysis was negative as regards malignancy, and indicated the presence of an inflammatory pseudotumor. This article raises the question of the problem in establishing a preoperative definitive diagnosis, as a correct diagnosis is often only confirmed following nephrectomy (in cases where the contralateral kidney is healthy).     

Inflammatory pseudotumors of the major salivary glands. Clinicopathologic and immunohistochemical analysis of six cases.

Inflammatory pseudotumor is a pathologic term used to describe reactive, pseudoneoplastic phenomena, which reportedly occur in many parts of the body. Clinicopathologic and immunohistochemical findings in six cases of inflammatory pseudotumor of the major salivary glands are described. All six lesions involved the parotid gland. There were three men and three women affected, with a median age of 72.5 years. All patients presented with a swelling of several months' duration in the parotid region. Five patients were alive and free of tumor at an average of 3.2 years after surgical removal, and one patient was lost to follow-up. The lesions were firm, discrete nodules, grossly described as homogenous yellow-gray tissue. Histologically, all lesions contained a diversified admixture of four histological elements: (a) myofibroblasts, (b) histiocytes, (c) plasma cells, and (d) lymphocytes. Results of immunohistochemical studies showed a biphasic spindle cell population of myofibroblasts and histiocytes with variable staining characteristics for KP-1(CD-3), smooth muscle actin, muscle-specific actin, and vimentin. These findings are in agreement with the concept that inflammatory pseudotumor is a fibroinflammatory lesion with an abundant component of myofibroblastic/fibrohistiocytic elements.     

A case of inflammatory myofibroblastic tumor recognized in the retroperitoneum and the kidney

A 61-year-old man consulted his local physician because of abdominal pain and was referred to our hospital after bilateral renal tumors were suspected on CT. CT and MRI showed a tumor, approximately 3 cm in diameter in the right renal pelvis and a cyst in the left kidney. There were no malignant cells detected on cytological studies of two urine specimens that were voided commonly and obtained from the right renal pelvis, respectively. Under a diagnosis of right renal pelvic tumor, the patient underwent laparoscopic right nephroureterectomy. Pathological examination demonstrated two inflammatory myofibroblastic tumors; one was located in the upper portion of the right kidney and the other was in the fatty tissue of the right renal hilus. There has not been any evidence of recurrence detected on follow-up for three months postoperatively.     

儿童输尿管炎性假瘤1例报告并文献复习

目的：探讨输尿管炎性假瘤(1nflammatory pseudotumor，IPT)的临床特点，提高其诊治水平。方法：报告1例9岁男性输尿管IPT患者，并复习文献就相关问题予以讨论。结果：术后患者恢复良好，痊愈出院。病理检查证实为输尿管IPT。结论：IPT指组织炎性增生形成的肿瘤样团块，根据症状、体征及影像学检查结果难与恶性肿瘤相鉴别，其确诊有赖于病理学检查。输尿管IPT治疗大多仍需行外科手术，并在治疗后进行随访。     

Inflammatory pseudotumor diagnosed by thoracoscopic resections; report of a case

A 65-year-old woman was referred to our hospital because of cough and sputum. Chest CT scan revealed a coin lesion (about 1.5 cm diameter) with slight speculation at the right upper lobe. We suspected a lung cancer and performed video assisted thoracic surgery (VATS). Under the thoracoscopy, the tumor was completely extirpated with safety margin by the partial resection of the right upper lobe. Pathological findings definitely revealed inflammatory pseudotumor, fibrohistiocytic variant type. VATS is a good indication for the diagnosis and treatment of inflammatory pseudotumor. This case was reported together with some reviews of the literature.     

A case of renal malacoplakia that was difficult to distinguish from cystic renal cell carcinoma

A 66 years old man visited our hospital with a chief complaint of right flank pain and abdominal palpable mass. Abdominal enhanced computed tomography scan showed a large cystic mass with infiltrating surrounding tissue in the right kidney. We diagnosed it infected cystic renal cell carcinoma because of high grade fever and acute inflammatory response. It was surgically unresectable tumor. Therefore, percutaneous puncture and drainage was performed under ultrasound guidance. In the culture of drainage fluid, Escherichia coli (E. coli) was isolated. Then, we confirmed reduction in the size of the tumor, right radical nephrectomy was performed. Because of tumor invasion to ascending colon, we performed the excision of right kidney together with ascending colon. Histological study confirmed target-shaped Michaelis-Gutmann body, and the definitive diagnosis was malacoplakia of the kidney. We reported a case of renal malacoplakia that was difficult to distinguish from cystic renal cell carcinoma. Our case is 12th case of renal malacoplakia in the Japanese literature.     

A case of xanthogranulomatous pyelonephritis--an experience of echo-guided aspiration biopsy for the diagnosis

Xanthogranulomatous pyelonephritis is a rare disease of the kidney. The pre-operative diagnosis of this disease is usually very difficult. Recently, echo-guided aspiration biopsy has been suggested for the differential diagnosis of the renal mass. We experienced a case of xanthogranulomatous pyelonephritis and performed echo-guided aspiration biopsy. A 57-year-old female was admitted to our hospital with complaints of upper abdominal pain and right lumbago. Judging from the findings obtained by intravenous pyelography, computed tomographic scan, ultrasonography and angiography, the lesion was a right renal inflammatory mass but renal tumor could not be denied. Because clear cell carcinoma was suspected from the results of echo-guided aspiration biopsy, right radical nephrectomy was performed. However, the resected kidney was diagnosed to be xanthogranulomatous pyelonephritis. Post-operative course was uneventful.     

Malignant fibrous histiocytoma originating in a renal capsule: a case report]

We report a case of malignant fibrous histiocytoma originating in a renal capsule. A 43-year-old woman was admitted with a chief complaint of right lower abdominal pain. Physical examination was unremarkable. Serum C-reactive protein and erythrocyte sedimentation rate increased to 3.8 mg/dl and 60 mm/hr., respectively. Computed tomography (CT) and magnetic resonance image (MRI) showed a heterogeneous enhanced mass, 4 x 9 x 13 cm in size, in contact with the lateral part of the right kidney. Selective right renal arteriography revealed a hypovascular tumor, the main feeding artery of which was the right adrenal artery. Preoperative clinical diagnosis was a retroperitoneal sarcoma and transabdominal tumor resection was performed. The adhesion between the tumor and the right kidney was so severe that right nephrectomy was also necessary for a radical surgery. The tumor, measuring 13 x 9 x 6 cm, was located laterally adhering to the right renal capsule. Microscopic examination of the tumor demonstrated spindle-shaped fibroblast-like cells arranged in a storiform pattern with fibrous stroma and clusters of rounded histiocyte-like cells and pleomorphic giant cells with bizarre nuclei. Histopathological diagnosis was malignant fibrous histiocytoma arising from the renal capsule and there was no tumor invasion to renal parenchyma. No adjuvant therapy was performed but she has remained well for 31 months since the operation without evidence of disease.     

Pulmonary inflammatory pseudotumor observed by bronchoscopy and resected using video-assisted thoracic surgery

Pulmonary inflammatory pseudotumor is rare. A 34-year-old woman visited our hospital due to an abnormal chest shadow. Computed tomograhy showed a nodule in the right upper lobe. Bronchoscopy showed a polypoid endobronchial nodule obstructing most of the orifice of B2a. The nodule was white, glossy, and smooth, and it seemed to be covered with bronchial mucosa. However, transbronchial biopsy could not facilitate a diagnosis. To obtain a definitive diagnosis, we performed lobectomy of the right upper lobe using video-assisted thoracic surgery and removed the nodule completely. The pathologic diagnosis made during surgery was inflammatory pseudotumor. Immunohistochemical examination showed proliferating spindle cells were positive for vimentin and smooth muscle actin, but negative for epithelial markers. These findings were consistent with the staining pattern of inflammatory pseudotumor previously reported. Careful follow-up is necessary to detect any sign of local recurrence and distant metastases.     

肾脏非肿瘤实性肿块诊治分析(附12例报告)

目的:提高肾脏非肿瘤实性肿块的诊治水平。方法:回顾12例的诊治过程,分析其临床表现、病理和影像学特点。结果:除肾炎性假瘤和肾血肿有可疑或明确的病史外,其余无明确病史;全部病例行B超、CT检查,1例肾血肿CT提示“血肿不能除外”其余均诊断肾癌或肾肿瘤。手术治疗7例,4例按肾癌行肾癌根治术,1例行肾切除术;2例行术中冷冻活检1例提示黄色肉芽肿性肾盂肾炎,1例提示肾炎性假瘤。5例未手术者观察随访1～4个月后B超复查包块均消失。结论:虽然B超、CT等影像学的检查对肾肿瘤有重要的诊断价值,但是临床医生不应过高评价这些影像检查的诊断学意义。提高诊断水平,术前影像学的复查,肾穿刺活检及术中行冷冻病理检查可减少误诊误治。     

Surgical treatment of an endobronchial inflammatory pseudotumor

A 62-year old man with an abnormal chest radiograph was referred to our hospital for further evaluation. Chest computed tomography (CT) revealed a 3.0 cm tumor on the hilum of the right S3 segment. Bronchofiberscopic findings showed a polypoid tumor arising from right B3. Brushing cytology under bronchofiberscopy couldnot diagnose the tumor. The tentative preoperative diagnosis was primary lung cancer or a metastatic lung tumor. To confirm the histopathological diagnosis, a right upper lobectomy was performed. Intraoperative histopathological examination showed a pulmonary inflammatory pseudotumor.     

A case of chromophobe cell renal carcinoma

We report a case of chromophobe cell renal carcinoma. A 27-year-old male suffered from right flank pain and gross hematuria. Drip infusion pyelography and ultrasonographic examination revealed a right renal mass and it was diagnosed as renal oncocytoma by needle biopsy of the right kidney. He was referred to our hospital for the operation and right radical nephrectomy was performed. The cut surface of the tumor was beige in color. The cytoplasm of the tumor cells stained positively for colloidal iron and showed a negative reaction for Vimentin. From these results, this tumor was given a diagnosis of chromophobe cell renal carcinoma.     

A case of renal pseudotumor associated with chronic pachymeningitis

BACKGROUND: A 56-year-old woman was referred to our hospital with a left renal mass. METHODS/RESULTS: Radiologic studies demonstrated a solitary space-occupying lesion in the left kidney and a malignant tumor was suspected. Left radical nephrectomy was then performed. Pathological examination revealed a sclerotic fibrous lesion with a rather distinct margin and no evidence of malignancy. These pathological findings were consistent with the diagnosis of a renal pseudotumor. CONCLUSIONS: This patient had a history of chronic pachymeningitis that formed a thoracic epidural focus causing spinal cord compression and the histologic appearance of this focus was similar to the renal lesion. It was concluded that this was a rare case of a renal pseudotumor associated with multifocal fibrosclerosis.     

Scalp metastases of a renal cell carcinoma

An 80-year-old man presented with a localized tumor of the right occipital scalp. The tumor was a 1-cm, bright red-purple, ulcerated, and crusted exophytic nodule on a smooth base (Figure 1). The lesion had grown asymptomatically over 18 months except for profuse bleeding induced by minimal trauma. It was extirpated with the clinical diagnosis of pyogenic granuloma vs. renal metastasis to the scalp. The patient's medical history included a transurethral prostatic resection 3 years earlier and, 1 year later, a right nephrectomy for a 2-kg kidney tumor verbally reported as "benign." The patient also had a 2-year history of untreated high blood pressure. Histopathologically, the excised tissue was an exo-endophytic nodule of a solid form composed of pleomorphic neoplastic cells with abundant clear cytoplasm, surrounded by fibrous collagen septae, blood vessel proliferation, and areas of hemorrhage (Figures 2 and 3). The histopathologic diagnosis of metastatic renal cell carcinoma was supported by immunohistochemistry with positive epithelial membrane antigen staining (Figure 4). Cytokeratins 7 and 20 were nonreactive. Laboratory studies revealed hematuria and elevated creatinine and urea nitrogen levels, but no malignant cells were observed in five urinary cytologies. Renal ultrasound showed the presence of two simple cysts in the left kidney and data compatible with chronic inflammatory disease.     

Surgically treated pulmonary inflammatory pseudotumor

We report 2 cases diagnosed as so-called pulmonary inflammatory pseudotumor. In case 1, a 28-year-old man with a slow growing 6-cm pulmonary tumor who underwent a right upper lobectomy was diagnosed with an inflammatory myofibroblastic tumor. In case 2, a 55-year-old man with chest pain and cough, who underwent open lung biopsy was diagnosed with plasma cell granuloma. Despite both diagnoses being classified as pulmonary inflammatory pseudotumors, we believe they should be classified differently.