Distant metastasis from benign solitary fibrous tumor of the kidney

Solitary fibrous tumor of the renal pelvis: A case report

BACKGROUND

Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm. SFT derived from the renal pelvis is an exceedingly rare entity. In this study, we report a case of renal pelvis SFT and review the relevant literature on this rare tumor.

CASE SUMMARY

A 76-year-old man was hospitalized due to right lumbar and abdominal pain. Abdominal computed tomography showed a hypervascular space-occupying renal lesion, sized 2.3 cm × 1.8 cm. Based on the computed tomography findings, the patient was diagnosed with right renal pelvis tumor and underwent nephrectomy. Postoperative immunohistochemical results confirmed the diagnosis. As of the 3-year follow-up, there were no signs of recurrence, and the patient has recovered well.

CONCLUSION

We report a rare case of SFT derived from the renal pelvis and discuss the imaging and histopathological features that distinguish renal pelvis SFT from other renal pelvis tumors.

BCOR Overexpression in Renal Malignant Solitary Fibrous Tumors: A Close Mimic of Clear Cell Sarcoma of Kidney

BCOR immunoreactivity is a sensitive and highly specific marker for clear cell sarcoma of the kidney (CCSK). However, a subset of adult renal sarcomas which overexpress BCOR are negative for BCOR genetic alterations, including BCOR gene fusions or BCOR-internal tandem duplication, and thus remain unclassified. We report 5 such undifferentiated renal/perirenal sarcomas which raised the differential diagnosis of CCSK due to their morphologic appearance and strong BCOR immunoreactivity, but which on RNA sequencing proved to be malignant solitary fibrous tumors (SFTs). The neoplasms occurred in patients at an age range of 30 to 62 years. Three patients were females and 2 male. Four were primary renal neoplasms while one was perirenal. All 5 neoplasms were cellular, nonpleomorphic, undifferentiated sarcomas with branching capillary vasculature composed of primitive round to ovoid neoplastic cells with scant cytoplasm and nuclei having fine, evenly dispersed chromatin. None of the cases demonstrated the typical hyperchromatic fusiform nuclei, prominent collagen deposition, or hemangiopericytomatous vasculature of SFT. All 5 cases were strongly immunoreactive for BCOR. Three cases were CD34 negative, where the other 2 were only focally CD34 positive. STAT6 was subsequently found to be positive by immunohistochemistry in all 5 cases. In summary, we report a previously unrecognized mimic of CCSK: malignant SFTs with an undifferentiated/small round cell phenotype along with branching capillary vasculature, strong immunoreactivity for BCOR, and minimal or no immunoreactivity for CD34. As CCSK is treated with a specific chemotherapy regimen, this distinction has therapeutic implications.

A solitary fibrous tumor/hemangiopericytoma of the fourth ventricle: case report and literature review

Solitary fibrous tumors/hemangiopericytomas (SFTs/HPCs) are rare in the central nervous system and intraventricular SFTs/HPCs are even rarer. We present a clinical case of SFT/HPC that was located in the fourth ventricle and performed a literature review of radiological findings of SFT/HPC. The patient was a 52-year-old man who presented to our hospital with dizziness and progressive weakness in his left extremities. Computed tomography and magnetic resonance imaging showed an irregular-shaped mass in the fourth ventricle. The upper anterior and lower posterior parts of the mass showed different densities and signal intensities, which formed a black and white sign. The upper anterior and lower posterior parts of the mass were enhanced to different degrees, and showed heterogeneous reversed enhancement. The patient underwent surgical resection and the mass was histologically confirmed to be an SFT/HPC. SFTs/HPCs of the fourth ventricle are rare, but show characteristic radiological presentations. In the present case, we observed a solid mass with flow voids, black and white sign, and heterogeneously reversed enhancement in the fourth ventricle. Collectively, these radiological features suggested the diagnosis of SFT/HPC.

Primary solitary fibrous tumor of kidney: A case report and literature review

Primary solitary fibrous tumors of kidney are rare in clinical practice. In literature, only eleven reported cases originated from renal pelvis. We report a case of a 45 year old middle-aged woman who was the first report that a small number of heterosexual cells have been found in urine. Definite diagnosis of this disease still depends on pathological examination, If preoperative puncture or other pathological examination supports the diagnosis of SFTs, the preferred treatment plan for it is surgical resection.

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.

Outcome of surgery in patients with solitary fibrous tumors of the pleura

Background

Solitary fibrous tumor of the pleura is rare, and the origin is submesothelial tissue. These tumors are seen in lung infrequently, and most are benign. We report our experience in the diagnosis and treatment of patients with solitary fibrous tumors of the pleura.

Methods

We studied 13 patients (6 men and 7 women, aged 26 to 76 years) with a diagnosis of benign solitary fibrous tumor of the pleura who were operated on from 2001 to 2014. One had a recurrent tumor after 10 years, and the others had primary tumors. Our approach was complete resection in all cases.

Results

After surgical excision, the most essential characteristic on histopathology was a neoplastic lesion composed of spindle-shaped tumor cells with hyperchromatic nuclei and eosinophilic bands of collagen. On immunohistochemical analysis, the cells were positive for desmin and negative for actin, synaptophysin, chromogranin, and CD117.

Conclusions

The essential step in the treatment of a patient with a diagnosis of benign solitary fibrous tumor of the pleura is complete resection. These patients should be followed up for a long time because of the possibility of late recurrence. Due to the rarity of these tumors, there has been no systematic assessment of the role of adjuvant therapy for benign solitary fibrous tumor of the pleura.

Metachronous Malignant Solitary Fibrous Tumor of Kidney: Case Report and Review of Literature

Solitary fibrous tumors are well described in the pleura, but rare extra-pleural neoplasms have been reported. We describe a patient with a solitary left renal fibrous tumor who after undergoing a nephrectomy, presented 8 years later with a contralateral metachronous solitary fibrous tumor. Malignant metastatic extra-pleural solitary fibrous tumors are extremely rare, and to our knowledge, this is the first case of contralateral recurrence of solitary renal fibrous tumor. The patient underwent a robotic assisted partial nephrectomy of the right renal mass. Both tumors showed overlapping histopathology.

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.

Solitary fibrous tumor of the kidney with focus on clinical and pathobiological aspects

Renal solitary fibrous tumor (SFT) is a rare, and a large scale study on this topic is lacking to date. In this article, we summarize the previously reported cases. The symptoms and signs resemble those of renal cell carcinoma, including hematuria, flank/abdominal/lumbar pain and palpable abdominal mass. Grossly, the tumor demonstrates a well-circumscribed solid mass. Microscopically, the tumor consists of fusiform or ovoid spindle cells and a various amounts of collagen bundles with patternless, storiform, or fascicular arrangements with an occasional hemangiopericytomatous pattern. Immunohistochemically, CD34, CD99 and bcl-2 are often detected. Ultrastructurally, tumor cells contain irregular nuclei, prominent Golgi apparatus, branching rough endoplasmic reticulum, variable numbers of mitochondria. Surgical resection is considered to be the gold standard therapy. Most of renal SFT are benign, but cases of approximately 10 to 15% behave in an aggressive fashion. All patients need to be on long-term follow-up because clinical behavior is rather unpredictable. As the molecular genetic study of renal SFTs is lacking, a large scale study will be desirable in the future.

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.

Metastases to the pancreas diagnosed by fine-needle aspiration

BACKGROUND

Metastatic cancer infrequently involves the pancreas. When the pancreas hosts a metastatic tumor, cytopathological evaluation of fine-needle aspirate material is a crucial part of the diagnostic process. In this study, we show two institutions' experience with cytopathological diagnosis of pancreatic metastasis.

METHODS

Databases of institutional experience at The Johns Hopkins Hospital and Ohio State University Medical Center were queried for cases of metastatic tumors in the pancreas that underwent fine-needle aspiration. Demographic and pathological features were compiled and the cytomorphology was reviewed.

RESULTS

Forty-two cases of tumor metastasis to the pancreas were found. Over the time of this review, 5,495 aspirates were performed, and 43% (2,389/5,495) had malignant cytological findings. Thus, the 42 cases of metastatic disease to the pancreas comprised 0.8% of all pancreas aspirates and 1.8% of the malignant ones. Renal cell carcinoma was the most common metastasis, followed by melanoma and non-small cell lung carcinoma. Among the other tumors in this series, 2 cases each of rare metastases such as the fibrolamellar variant of hepatocellular carcinoma and solitary fibrous tumor were also seen.

CONCLUSION

The pancreas is rarely involved with metastatic disease, but when it is involved the most common tumor is renal cell carcinoma followed by melanoma and non-small cell lung cancer. Clinical history and awareness of the primary pancreatic mimickers are necessary for arriving at the correct diagnosis. As conventional pancreatic adenocarcinoma is uncommon in children and young adults, history of other tumors - even ones that usually follow an indolent course - is essential.

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.