Solitary Fibrous Tumor of the Kidney with Massive Retroperitoneal Recurrence. A Case Presentation

A case of the world's largest renal cell carcinoma

INTRODUCTION

Renal cell carcinoma is often discovered at an early stage due to the increased use of imaging studies in the current era; therefore, its presentation as a gigantic renal cell carcinoma is rarely encountered.

CASE PRESENTATION

A 59-year-old male presented to our hospital due to dizziness, fatigue, and increasing abdominal distension. A computed tomography scan showed an extremely large mass occupying most of the abdomen and pelvis. Surgical resection of the mass was performed. The largely cavitary mass with fibrous capsule was 43 cm and 13.0 kg, and contained a large amount of necrotic tissue. A portion of the left kidney was identified at the periphery of the mass, indicating that the tumor was arising from the left kidney. The final pathologic diagnosis was type 1 papillary renal cell carcinoma.

CONCLUSION

To the best of our knowledge, this tumor is the world's largest malignant renal tumor.

Solitary fibrous tumor of the kidney: Magnetic resonance imaging characteristics in 4 patients

To investigate the characteristics of magnetic resonance image (MRI) in solitary fibrous tumor (SFT) of the kidney.MRI findings and clinical features of SFT of the kidney in 4 patients (2 men and 2 women with a mean age of 37.8 ± 8.7 years) were reviewed retrospectively. All patients were scanned by a 3.0-T magnetic resonance (MR) imaging system and the lesions were detected with emphasis on size, shape, location, margin, presence of pseudocapsule, signal intensity, degree of MR enhancement, and apparent diffusion coefficient (ADC).The 5 tumors from 4 patients were located in renal parenchyma (n = 1), renal pelvis (n = 3), and renal capsule (n = 1). On MRIs, the tumors were round (n = 1) or oval-shaped (n = 4), and presented pseudocapsule (n = 2) and well-circumscribed margins (n = 3) can be found. On T2-weighted images (T2WIs), solid components of the tumor presented homogeneously mild hypointensity or isointensity (n = 4) compared with the renal cortex. On diffusion-weighted images (DWIs), the lesions showed normal or mild hyperintensity (n = 4) with mean ADC of 1.687 × 10 mm/s. On dynamic contrast-enhanced MRIs, all lesions showed progressively mild enhancement. In the follow-up of 24 to 36 months after the surgery, 3 patients survived and 1 deceased.The SFT of the kidney appeared as a circle or oval and presented homogeneously mild hypointensity or isointensity on T2WIs, hyperintensity on DWIs, and progressively mild enhancement on DCE MRIs.

Solitary Fibrous Tumor of the Kidney Developing Local Recurrence

Solitary fibrous tumor (SFT) of the kidney is a rare entity and usually displays a favorable prognosis. We herein report a second case of renal SFT developing local recurrence. A 50-year-old man was referred to our hospital because of a left renal mass. An abdominal CT detected a large renal tumor and radical nephrectomy was performed with a possible diagnosis of renal cell carcinoma. The resected tumor size was measured at 17 × 11 × 8 cm. Grossly, necrosis was observed in central lesion of the tumor but hemorrhage was not observed. Microscopically, the tumor consisted of spindle-shaped cells with scant cytoplasm accompanied by hyalinized collagenous tissue, which displayed hemangiopericytomatous patterns. The cellularity was normal and nuclear pleomorphism was not observed. Ki-67 labeling index was less than 3%. The pathological diagnosis of SFT was made without obvious malignant findings. Three years after the surgery, a follow-up CT scan detected a mass lesion in the tumor bed. Surgical resection was performed and the resected tumor was compatible with local recurrence of the SFT without obvious malignant findings. Renal SFT should be carefully monitored even in the absence of obvious malignant findings.

A GRIA2 and PAX8-positive renal solitary fibrous tumor with NAB2-STAT6 gene fusion

Solitary fibrous tumor (SFT) is a rare neoplasm composed of mesenchymal-derived spindle cells. Although SFT occurs anywhere in the body, they most frequently affects the thoracic region. Here, we reported an extremely rare case of an extrathoracic SFT occurring primarily in the kidney. To our knowledge, little information has been described on the immunohistochemistry (IHC) and genetics of renal SFT.

A 41-year old Japanese female came to our hospital for further examination of a left kidney mass detected incidentally with ultrasound. Extensive investigation of the tumor, including physical, laboratory, and image examinations led to a clinical diagnosis of renal cancer (cT1aN0M0), which were in most parts imbedded in the lower polar parenchyma. The patient underwent laparoscopic radical nephrectomy. The mass was diagnosed pathologically as SFT originating from the kidney, but not as renal carcinoma. Microscopically, the tumor was composed of spindle-shape cells distributed variably in dense collagenous stroma and had a focal hemangiopericytomatous staghorn-like vascular pattern. Mitotic figures, atypical structures, necrosis and hemorrhage were not identified. No adjuvant therapies were given postoperatively. The patient has been free of tumor recurrence for 25 months since the surgery. IHC revealed that the tumor diffusely expressed CD34, CD99, Bcl2, PAX8, NAB2, STAT6, and GRIA2. The tumor stained negatively for desmin, S-100, c-Kit, CK-AE1/AE3, CDK4 and MDM2. A NAB2-SATA6 gene fusion was detected in tumor cells by reverse transcription-polymerase chain reaction, direct sequencing, and an in situ proximity ligation brightfield assay. The gene fusion occurred as an 831 bp truncation of exon 2 in NAB2 connected to the beginning of exon 3 in STAT6. We have reported a case of GRIA2 and PAX8-positive SFT occurring primarily in the kidney with such NAB2-STAT6 gene fusion for the first time. Diffuse expression of PAX8 in the tumor might present with a renal origin. Reportedly, benign histology of SFT cannot necessarily predict favorable clinical prognosis. Genetic alterations recently identified in SFT could possibly refer to risk stratification for tumor recurrence. However, malignant preponderance of extrathoracic SFT over thoracic SFT remains unexplained so far. Long-term follow-up after surgery should be performed in the present case.

A huge malignant solitary fibrous tumor of kidney: case report and review of the literature

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1603694556107408.

Solitary fibrous tumor (SFT) is a spindle cell neoplasm that rarely occurs in the kidney. Malignant SFT of the kidney is particularly rare. Here, we report a 66-year old woman with a right flank mass that has been proved clinically and radiographically. Grossly, the largest diameter of the mass were measured up to 23 cm, was poorly circumscribed. Approximately 80% of the neoplasm consisted of hyperchromatic and pleomorphic spindled cells surrounding staghornlike blood vessels. Tumor cells frequently had mitoses and necrosis. However, the remainder of the mass was composed of haphazard, storiform or short fascicular arrangements of spindle cells in a loose myxoid to fibrous stroma. Immunohistochemically, we observed diffusely strong CD34 staining and an 85% Ki-67 proliferative index. The tumor partly showed negative CD34 and a 20% proliferative index. To our knowledge, this is the largest malignant renal SFT in the reported literatures and shows an obviously high proliferative index.

Malignant solitary fibrous kidney tumor with peritoneal disease: a case report

We report a case of a large malignant solitary fibrous kidney tumor. A complete surgical resection of the primary tumor and peritoneal disease was carried out, and a histological examination confirmed the initial diagnosis. We describe and discuss the characteristics of this rare kidney neoplasm.

Solitary fibrous tumour of the kidney: case report with review of the literature

Solitary Fibrous Tumour (SFT) is an unusual spindle cell tumour that usually occurs in the pleura, but has recently also been reported to be extra-pleural in origin. A renal presentation is very rare. Upto 90% of the tumours have benign characteristics. It is difficult to differentiate it from renal cell carcinoma by using imaging techniques. A definitive diagnosis can be made by doing a detailed pathological examination, which includes immunohistochemistry. We are reporting a case of a large solitary fibrous tumour of the kidney which here occurred in a 70-years-old male. Histological examination of the resected specimen confirmed the diagnosis, by revealing strongly positive reactions of the neoplastic cells for CD34, bcl-2, vimentin and negativity for Epithelial Membrane Antigen (EMA), Smooth Muscle Actin (SMA), S-100 protein and Ki-67. The patient suffered a cardiac arrest and died on the seventh day after his surgery.

Pediatric Renal Solitary Fibrous Tumor

Solitary fibrous tumors (SFTs) are unusual spindle cell neoplasms initially described in the pleura but have since been discovered in many extrapleural locations. SFT of the kidney is extremely rare, the majority occurring in middle-aged adults. To date, only two pediatric cases of renal SFT have been reported. We report a case of large SFT in the kidney of a 3-year-old boy that was clinically and radiologically thought to be a nephroblastoma. This case is the first pediatric renal SFT to be reported with detailed histopathologic and cytogenetic analyses. SFT should be included in the differential diagnosis of pediatric renal tumors.

Pancreatic metastasis from a solitary fibrous tumor of the kidney: a rare cause of acute recurrent pancreatitis

Solitary fibrous tumors are unusual spindle cell neoplasms that uncommonly originate from the kidney. We report a case of a 43-year old male who presented with acute recurrent pancreatitis secondary to a mass in the head of the pancreas. Endoscopic ultrasound with fine needle aspiration (EUS-FNA) was performed. Cytology revealed solitary fibrous tumor of the kidney. This is the first reported case of solitary fibrous tumor metastasizing to the pancreas and presenting as acute recurrent pancreatitis.

Solitary fibrous tumours of the pleura: report of two cases and literature review

BACKGROUND

Solitary fibrous tumours of the pleura (SFTPs) are rare pleural mesenchymal neoplasms with distinct clinicopathological and immunohistochemical features, accounting for less than 5 % of all neoplasms involving the pleura.

METHODS

We present two cases of SFTP with a review of the current literature.

RESULTS

Clinical presentation varies according to size and intrathoracic localisation. The molecular pathology of SFTPs is largely unknown. Complete surgical resection is recommended with long-term clinic and radiographic follow-up due to its malignant potential.

CONCLUSIONS

This is a summary of available literature outlining current clinical practice in the diagnosis, management, and treatment of SFTPs in Ireland.