Solitary fibrous tumors of the spine: a pediatric case report with a comprehensive review of the literature

The Role of MRI in the Diagnosis of Spinal Cord Tumors

Spinal cord tumors are uncommon, and its multiple representatives not always have pathognomonic characteristics, which poses a challenge for both patients and caring physicians. The radiologist performs an important role in recognizing these tumors, as well as in differentiating between neoplastic and non-neoplastic processes, supporting clinical and surgical decision-making in patients with spinal cord injury. Magnetic Resonance Imaging (MRI) assessment, paired with a deep understanding of the various patterns of cord involvement allied to detailed clinical data can provide a diagnosis or significantly limit the differential diagnosis in most cases. In this article, we aim to review the most common and noteworthy intramedullary and extramedullary spinal tumors, as well as some other tumoral mimics, with an emphasis on their MRI morphologic characteristics.

Spinal Solitary Fibrous Tumors: An Original Multicenter Series and Systematic Review of Presentation, Management, and Prognosis

All solitary fibrous tumors (SFT), now histologically diagnosed by a positive nuclear STAT6 immunostaining, represent less than 2% of soft tissue sarcomas, with spinal SFT constituting a maximum of 2% of them, making these tumors extremely rare. We provide an up-to-date overview of their diagnosis, treatment, and prognosis. We included 10 primary STAT6-positive SFT from our retrospective cohort and 31 from a systematic review. Spinal pain was the most common symptom, in 69% of patients, and the only one in 34%, followed by spinal cord compression in 41%, radicular compression, including pain or deficit, in 36%, and urinary dysfunction specifically in 18%. Preoperative diagnosis was never obtained. Gross total resection was achieved in 71%, in the absence of spinal cord invasion or excessive bleeding. Histologically, they were 35% grade I, 25% grade II, and 40% grade III. Recurrence was observed in 43% after a mean 5.8 years (1 to 25). No significant risk factor was identified, but adjuvant radiotherapy improved the recurrence-free survival after subtotal resection. In conclusion, spinal SFT must be treated by neurosurgeons as part of a multidisciplinary team. Owing to their close relationship with the spinal cord, radiotherapy should be considered when gross total resection cannot be achieved, to lower the risk of recurrence.

Recurrent Solitary Fibrous Tumor in Intradural Extramedullary Space: Case Report and Review of the Literature

Solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is a rare neoplasm arising from spindle cells and most commonly arising from pleura. Spinal SFT/HPC is a rare entity; hence, it is not on the top of the differential diagnosis list when a clinician faces a spinal lesion. In the review of the literature, there exist less than 50 case reports of intradural extramedullary SFT/HPC. Here, we present a 54-year-old female patient who underwent subtotal surgical excision of an intradural extramedullary spinal mass pathologically reported to be SFT/HPC and had symptomatic recurrence in the 3^rd year of follow-up. Surgical intervention was unachievable and the patient was given 45 Gy to the surgical cavity followed by a 5.4 Gy boost to visible tumor with external radiotherapy. Patient reported significant relief of her symptoms. We aim to contribute to the formation of a treatment algorithm for this rare entity.

Two cases of solitary fibrous tumor/hemangiopericytoma with different clinical features according to the World Health Organization classification: case report and review of the literature

Solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) have been classified as one entity by the World Health Organization in 2016 due to gene fusion between NAB2 and STAT6. In the Central Nervous System (CNS), a hypocellular, collagenized tumor with a classic SFT phenotype is considered grade I, whereas more densely cellular tumors mostly corresponding to the HPC phenotype are classified as grade II or III (anaplastic) depending in mitotic count (<5 vs. >5 mitoses per 10 high-power fields). Herein, we report two cases of targeted SFT/HPC in which pathological differences and WHO grading affect clinical features. A 75-year-old woman presented with headache and had an intradural extramedullary tumor at the C1 to C2 level. The tumor was well-circumscribed and attached only to the dura mater. It was totally removed and diagnosed SFT/HPC grade I. In contrast, a 68-year-old woman presented with numbness in the right upper limb and had an intradural extramedullary tumor at the medulla to C3 levels The tumor was irregularly marginated and strongly adherent to the spinal cord and involved the vertebral artery. It was sub totally removed and diagnosed SFT/HPC grade II. To the best of our knowledge, there are only 12 cases of SFT/HPC at the craniocervical junction, including the present two cases, of which four that were adherent to the spinal cord or involved the vertebral artery were grade II or III. Although the location of the tumor was almost the same, there were significant differences in the intraoperative findings according to the WHO grading.

Cervical intramedullary solitary fibrous tumor: Case report and review of the literature

Background:

Solitary fibrous tumors (SFTs) are benign tumors derived from mesenchymal tissues that predominantly occur in the pleura. Establishing the diagnosis of these very rare intramedullary spinal lesions, with no clear-cut pathognomonic radiographic characteristics, is particularly challenging.

Case Description:

Two males, 30 and 41 years of age, presented with progressive cervical myelopathies attributed to a cervical intramedullary exophytic tumor with associated spinal cord edema. One patient showed that the lesion was highly vascularized. Both patients underwent surgical excision of firm, solid, focal, and, particularly in one of them, very vascular/hemorrhagic tumors; at surgery, there was some adherence between the tumors and the cord tissue, but gross-total resections were achieved in both cases, demonstrated on postoperative MR scans. Histological and immunohistochemical findings confirmed the diagnosis of SFT (WHO Grade I). After a 6-month postoperative period, both patients neurologically improved and had no MR evidence of tumor recurrence.

Conclusion:

Intramedullary cervical exophytic SFTs are extremely rare. Although these solid tumors may present with hemorrhagic features and at surgery demonstrate significant adherence to the pial/cord surface, complete surgical resections are feasible resulting in good outcomes.

Solitary Fibrous tumor of the lumbar spine mimicking a sequestered disc fragment

Solitary fibrous tumor in the lumbar spine is a rare pathology with non-specific radiographic features, sometimes resulting in misdiagnosis. Our patient was a 41-year old female who presented with low back pain and bilateral leg pain. Initial MRI showed a lesion misdiagnosed for a sequestered disc at the mid L4-5 level, which was subsequently characterized appropriately and treated surgically, with resolution of symptoms. Pathologic diagnosis was most consistent with a solitary fibrous tumor due to STAT 6 and CD 34 reactivity. Long-term follow up is recommended in these patients to monitor tumor recurrence and evidence of metastasis.

De-differentiation associated with drop metastasis of a recurrent intracranial solitary fibrous tumor: a case report and literature review

BACKGROUND

Central nervous system is a rare occurring location of solitary fibrous tumors (SFTs). SFTs have a potential for recurrence, which is the leading cause of death in patients with these disease entities. De-differentiation phenomenon combined with cerebrospinal fluid (CSF) dissemination through drop metastasis of STFs from intracranial to intraspinal has only been reported in extremely limited cases.

CASE DESCRIPTION

Herein, we present a case of SFT in a 54-year old male. MRI showed characteristic of mixed high and low signal with 6.3 cm × 6.5 cm × 5.9 cm. After radical surgical resection, the pathology indicated benign SFT. However, MRI re-examination of 22 months later detected local recurrence, concomitant with spreading of intracranial and intraspinal through CSF dissemination. And interestingly, the second pathology found de-differentiation phenomenon and malignance of SFT, in which some areas transformed to rhabdomyosarcoma.

CONCLUSION

This is the first case report of recurrent intracranial SFT de-differentiating to rhabdomyosarcoma concurrent with CSF pathway drop metastasis. Benign intracranial SFTs have the potential of de-differentiation, which may play an important role in its distant metastasis. The underlying molecular biological and pathological mechanisms of benign SFT malignance transformation still warrant further exploration.

A Rare Case of a Primary Spinal Solitary Fibrous Tumor/Hemangiopericytoma in a 9-Month-Old Patient

BACKGROUND Solitary fibrous tumors (SFTs)/hemangiopericytomas (HPCs) are mesenchymal tumors commonly found in middle-aged patients, usually localized to thoracic pleurae. Spinal tumor involvement is rarely seen, and its imaging findings are largely inconsistent because of the rarity of these cases. We present a case report of a 9-month-old girl with a rare intraspinal tumor with histologic evidence of SFT/HPC, but no STAT6 nuclear immunoreactivity. CASE REPORT A 9-month-old girl, born at term with good prenatal care, presented to the emergency room with regression of developmental milestones. The patient was in good health until 2 months, when she developed decreased spontaneous leg movements. Physical exam revealed diffuse muscular atrophy, with no deep tendon reflexes, sensation, or spontaneous movements of the lower extremities. Computed tomography and magnetic resonance imaging showed a heterogeneous irregular mass filling the lumbosacral spinal canal, extending through the neural foramina to the prevertebral/perivertebral and presacral regions. The tumor was biopsied and referred to the National Institutes of Health for consultation and the diagnosis of SFT/HPC was confirmed on the basis of its histologic features, despite the fact that the tumor was negative for STAT6 immunoreactivity. CONCLUSIONS Although the tumor histology was consistent with SFT/HPC, it was negative for STAT6 nuclear immunoreactivity, which is unusual and may exclude the diagnosis. To our knowledge, this is the youngest patient to present with a spinal SFT with these features.

Single Solitary Fibrous Tumor Brain Metastasis in a Patient with Simultaneous Adenocarcinoma of the Lung: Case Report and Review of the Literature

We present a unique case of a patient simultaneously diagnosed with solitary fibrous tumor (SFT) and unrelated adenocarcinoma of the lung, both proven with separate pathology. It was subsequently found that the SFT had metastasized to the brain by additional pathology, and not the predicted adenocarcinoma. SFTs are a rare mesenchymal neoplasm that accounts for less than 2% of all reported soft tissue tumors. SFTs most commonly arise in the thoracic cavity, but are frequently found in various locations throughout the body, and rarely metastasize to the brain. This case highlights that rare neoplasms, such as SFT, should not be ruled out as a potential cause of metastasis. Due to the rarity of this clinical situation, we also provide a review and discussion of previously reported SFT cases and the use of postoperative radiation therapy. The optimal treatment for individual patients remains unclear in this unique situation. Surgical resection followed by adjuvant Gamma Knife radiation therapy to the surgical bed appears to be a safe option for local treatment of SFT in select patients. Further studies are needed of this rare clinical situation in order to better understand and optimize future treatments for patients with SFT and metastasis to the brain.

Intradural Extramedullary Spinal Neoplasms: Radiologic-Pathologic Correlation

While intradural extramedullary spinal disease varies widely, identification of tumors in this location and their radiologic manifestations greatly facilitates narrowing of the diagnostic considerations. Meningioma and schwannoma are the two most common intradural extramedullary tumors, and both are associated with neurofibromatosis. Meningiomas are most common in the thoracic spine and show a strong female predilection and a clinical manifestation related to compression of the spinal cord or nerve roots. Schwannomas typically are associated with radicular pain and other sensory symptoms. Melanotic schwannoma frequently shows T1 hyperintensity at MRI related to the presence of paramagnetic free radicals in melanin. Neurofibroma, known for its T2 hyperintensity, frequently involves the cervical spine, where it may make surgical resection challenging. Less commonly, malignant peripheral nerve sheath tumor commonly mimics the imaging appearance of a schwannoma but has decidedly more aggressive biologic behavior. In the cauda equina, myxopapillary ependymoma and paraganglioma are believed to arise from the filum terminale and have characteristic imaging manifestations based on their underlying pathologic features. Recent identification of a common genetic marker has led to reclassification of what had previously been regarded as separate tumors and are now known as solitary fibrous tumor/hemangiopericytoma. In the proper clinical setting, the presence of nodular intradural enhancement strongly suggests the presence of leptomeningeal metastatic disease, even when results of cerebrospinal fluid analysis are negative. This article highlights the characteristic neuroimaging manifestations of these neoplasms, with emphasis on radiologic-pathologic correlation. See Illumination by Frazier .

Cervical, Intradural Extramedullary Solitary Fibrous Tumor of the Spinal Cord: A Case Report and Review of the Literature

Solitary fibrous tumors (SFTs) are rare, spindle cell neoplasms of the mesenchymal origin. Lesions localized to the spine are exceptionally uncommon, only described in the literature in case reports and small case series. While these lesions are typically benign, there are a few reports in which they recur or present as malignancies. The patient presented in the case herein was a 72-year-old male, who presented with a 1-year history of lower extremity weakness, pain, and numbness and was found to have a cervical, intradural extramedullary tumor. In addition to the case report, the authors perform a thorough review of all previously published cases of spinal SFT.

Intradural-Extramedullary Solitary Fibrous Tumor/Hemangiopericytoma with a Negative Result on Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

Intradural-extramedullary solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is a rare entity. SFT/HPCs can recur after surgery, even if a benign histology of the tumor is observed. We herein report a 68-year-old woman with intradural-extramedullary SFT/HPC. On magnetic resonance imaging (MRI), the intradural-extramedullary mass was isointense on T1-weighted images and hypointense on T2-weighted images with heterogeneous gadolinium enhancement. Whole-body fluorodeoxyglucose-positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) was also performed, showing no accumulation. We performed surgery for the intradural-extramedullary mass, and the pathological findings of the resected specimen were a benign histology consistent with World Health Organization (WHO) grade I SFT/HPC. She had no evidence of tumor recurrence three years after the surgery for intradural-extramedullary SFT/HPC. ¹⁸F-FDG-PET/CT before surgery may be useful for predicting the postoperative behavior of spinal SFT/HPCs.

Solitary Fibrous Tumor/Hemangiopericytoma of Spinal Cord: A Retrospective Single-Center Study of 16 Cases

OBJECTIVE

In this study, we retrospectively reviewed our experience in the surgical management of solitary fibrous tumor (SFT)/hemangiopericytomas (HPCs) of the spinal cord.

METHODS

Sixteen patients with SFT/HPCs of the spinal cord were enrolled in this study. Data on clinical presentation, radiologic findings, histopathologic features, surgical treatment, adjuvant therapy, and prognosis were retrospectively reviewed. Kaplan-Meier curves and log-rank tests were used to identify the prognostic factors for recurrence and overall survival (OS).

RESULTS

Our series included 6 men and 10 women, with a male/female ratio of 1:1.7. Magnetic resonance imaging (MRI) showed slightly hyperintense lesions on T2-weighted images for all 16 patients. All tumors showed positive immunohistochemical staining for signal transducer and activator of transcription 6. Statistical analysis of clinical data showed that age, gender, tumor location, tumor size, medullary compartment location, and Ki-67 index were not associated with recurrence and OS (P > 0.05). However, World Health Organization grade III was significantly associated with recurrence (P < 0.01). Gross total resection (GTR) and postoperative radiotherapy significantly reduced recurrence (P < 0.01 and P < 0.05), but only GTR showed remarkable benefits to improve OS (P < 0.05).

CONCLUSIONS

SFT/HPCs of spinal cord are rare neoplasms with a propensity to recur. Hyperintensity on T2-weighted magnetic resonance imaging combined with positive immunohistochemical staining for signal transducer and activator of transcription 6 are important clues for classification and differentiation of these tumors. The extent of resection, World Health Organization grade, and postoperative radiotherapy might be predictive factors for recurrence. Complete tumor resection should be sought whenever possible, and adjuvant radiotherapy is recommended after surgical resection. Moreover, regular and long-term follow-up is mandatory to monitor recurrence.

Surgical treatment of primary solitary fibrous tumors involving the pelvic ring

The surgical treatment of primary solitary fibrous tumors (SFT) involving the pelvic ring has not been reported previously. In this study, we aimed to evaluate the efficacy of surgical treatment for this disease. From 2009 to 2015, 13 patients underwent tumor resection at our hospital, with an average age of 49.5 years (27–68 years). Four patients underwent en bloc resection, and 9 patients underwent piecemeal resections. A Chi-square test was used to compare the postoperative recurrence rates between the en bloc resection and the piecemeal resection groups (p = 0.68), and no significant difference was found between the benign and malignant solitary fibrous tumor groups (p = 0.44). The 5-year survival rate of the patients in this study was 83.3%, and the 5-year progression-free survival rate was 63.5%. The progression-free survival rate was not significantly different between the en bloc resection and piecemeal resection groups (p = 0.97). Piecemeal resection can also achieve acceptable local control, particularly for patients with sacral tumors, as they may achieve even better postoperative function with sacral nerve preservation. Recurrence and metastasis occur relatively late in the course of this disease. Therefore, long-term follow-up is required.

Solitary fibrous tumour of the spine: imaging features of a commonly misdiagnosed entity

OBJECTIVE

Solitary fibrous tumours (SFTs) occurring in the spine are rare. Herein, we review the clinical and imaging data of spinal SFT.

METHODS

We retrospectively analysed eight cases of pathologically confirmed spinal SFT imaging and clinical data, pathological manifestations, surgical methods, and follow-up results.

RESULTS

Five SFTs cases occurred in the cervical spine, two in the thoracic spine, and one in the lumbosacral spine. Five cases showed a dumbbell-shaped or lobulated soft tissue mass that grew across the intervertebral foramen, two cases showed an expansive intraosseous mass formation in the vertebral body and/or posterior element, and one case showed a long-spindle shaped intraspinal canal mass growing along the spinal canal. Seven caused local invasion and destruction of the vertebral body and posterior element. Benign SFTs displayed a good prognosis, whereas malignant SFTs were prone to recurrence and metastasis (3/4).

CONCLUSION

Spinal SFTs are difficult to characterise with imaging and required pathological and immunohistochemical investigation. Prolonged follow-up is recommended once a diagnosis of spinal SFTs has been established because of the unclear biology.

KEY POINTS

• Spinal solitary fibrous tumours are extremely rare. • SFTs should be showed the differential of masses developing though the foramen. • Combing imaging with pathology and immunochemistry assesses the diagnosis and establish nature.

Solitary fibrous tumor of the abdominal wall re-surfacing as unilateral pleural effusion and mass: A case report and review of the literature

Background

Solitary fibrous tumors (SFTs) are rare fibroblastic mesenchymal neoplasms that were initially described in the pleura, but have been increasingly recognized to occur in other parts of the body. They have been traditionally regarded as indolent tumors that are rare to metastasize after surgical resection. Here, we describe a case of a Filipino female who initially presented with unilateral pleural effusion and mass, and was ultimately diagnosed with recurrent solitary fibrous tumor that originated from the abdominal wall. Then, we reviewed existing literature on intra- and extrathoracic SFTs with focus on pathological characteristics, recommendations for treatment as well as post-treatment surveillance.

Case presentation

A 79-year-old Filipino female with a history of solitary fibrous tumor of the abdominal wall status post complete surgical resection 3 years ago presented with unilateral pleural effusion and mass, and was diagnosed with recurrent solitary fibrous tumor that metastasized to the lung. She was not a candidate for systemic chemotherapy and ultimately died 1 year later from progressive respiratory failure.

Conclusions

Solitary fibrous tumor are rare mesenchymal tumors that were initially described in the pleura, but have now been reported in many other sites. Complete surgical resection is the mainstay therapy for all cases; however, long-term monitoring and surveillance several years after initial presentation is crucial to prevent disease recurrence, and adjuvant treatment may be necessary for patients with high-risk features. Additional studies are needed to demonstrate the clinical utility of risk stratification models and to develop post-treatment surveillance guidelines for extrathoracic SFTs.