Solitary Fibrous Tumor of Central Nervous System: A Case Report

Successful multimodal management of central nervous system solitary fibrous tumor: A case report

Solitary fibrous tumors (SFTs) are rare neoplasms that can occur in various locations, including the central nervous system (CNS). We present a case report of a 47-year-old male patient with an intracranial SFT who underwent subtotal resection followed by adjuvant radiotherapy. The patient initially presented with chronic left temporal headache and was diagnosed with an intra-axial double-component mass in the left temporoparietal lobe. Histopathological examination confirmed the diagnosis of SFT, and immunohistochemical staining demonstrated positivity for CD34, Bcl-2, and STAT6. Following the incomplete resection, the patient received adjuvant radiotherapy using volumetric modulated arc therapy (VMAT) technique. During radiotherapy, the patient experienced a spontaneous encephalocele rupture but recovered without complications. One year postradiotherapy, the patient showed no recurrence of symptoms or radiological evidence of tumor recurrence. This case highlights the challenges in the diagnosis and management of CNS SFTs and suggests that subtotal resection followed by adjuvant radiotherapy may be an effective treatment approach in achieving favorable outcomes for these rare neoplasms.

Intracranial solitary fibrous tumors: Clinical, radiological, and histopathological insights along with review of literature

BACKGROUND

Intracranial solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms, often challenging to diagnose due to their resemblance to meningiomas and other central nervous system tumors. While advancements in molecular genetics have aided in classification, diagnostic nuances and optimal management strategies remain areas of interest.

MATERIALS AND METHODS

This retrospective study analyzed 11 cases of intracranial SFTs treated at a neurosurgical centre in India between February 2020 and January 2024. Clinical data, radiological findings, histopathological features, and follow-up details were reviewed. Immunohistochemistry, particularly STAT6, facilitated diagnosis confirmation.

RESULTS

The median age of presentation was 32 years, with a male predominance. Headache was the most common presenting symptom, often leading to misdiagnosis as meningiomas on radiological imaging. Histologically, SFTs exhibited spindle to ovoid cells with staghorn vessels and collagenized stroma, posing challenges in differential diagnosis. WHO grading predominantly revealed grade 1 tumors, though recurrence occurred, emphasizing the importance of long-term follow-up. Immunohistochemistry, particularly STAT6, played a pivotal role in distinguishing SFTs from other entities.

CONCLUSION

Intracranial SFTs present diagnostic challenges due to overlapping features with other tumors, warranting a comprehensive approach integrating clinical, radiological, and histopathological findings. Immunohistochemistry, particularly STAT6, emerges as a valuable diagnostic tool. Long-term follow-up is essential for monitoring recurrence and potential malignant transformation. Further research is needed to delineate optimal treatment strategies, including the role of radiotherapy in SFT management.

Solitary fibrous tumor of the central nervous system invading and penetrating the skull: A case report

Solitary fibrous tumor (SFT) of the central nervous system is a rare spindle cell tumor of mesenchymal origin. The present study reports the case of a 44-year-old male patient with SFT. Magnetic resonance imaging demonstrated that the majority of the intracranial tumors exhibited uneven low signals on T1-weighted imaging (T1WI) and low mixed signals on T2WI, and there was an enhancement on enhanced scanning. Furthermore, the distal part of the left occipital lobe exhibited hypersignals on T1WI and T2WI, and this was significantly enhanced following enhanced scanning. The lower part of the scalp exhibited low signals on T1WI and high signals on T2WI, and there was no notable enhancement following enhanced scanning. Magnetic resonance spectroscopy demonstrated an elevated choline/creatine peak in the solid part of the tumor. Under the microscope, the tumor exhibited characteristic 'staghorn-shaped' blood vessels. As SFT is difficult to differentially diagnose via imaging, immunohistochemical analysis of CD34, vimentin and signal transducer and activator of transcription 6 was performed for the definitive diagnosis of SFT. Of note, surgical resection was the preferred treatment for SFT; however, due to the rarity of the tumor, subsequent adjuvant therapy and prognosis require further investigation.

A Rare Case of a Primary Leiomyoma of the Clivus in an Immunocompetent Patient and a Review of the Literature Regarding Clival Lesions

Leiomyomas are common lesions that are usually located in the genitourinary and gastrointestinal tracts. Primary leiomyomas at the skull base are uncommon. They are composed of well-differentiated smooth muscle cells without cellular atypia. The diagnosis of a leiomyoma has to be confirmed by immunohistochemistry. The tumor tissue is immunoreactive for SMA, S100 and cytokeratin. Leiomyomas mainly occur in immunocompromised patients. Most tumor tissues are positive for EBV. The presented case is that of a 56-year-old immunocompetent woman with a tumor on the clivus. The radiological images suggested chordoma or fibrous dysplasia. Transnasal transsphenoidal surgery was performed. The tumor tissue consisted of well-differentiated smooth muscle cells with elongated nuclei. Immunohistochemistry revealed a positive reaction for desmin, SMA and h-Caldesmon and a negative reaction for S100, beta-catenin, PGR and Ki67. The leiomyoma diagnosis was subsequently established. To the best of our knowledge, the case of a primary leiomyoma on the clivus of an immunocompetent patient is the first to be described. We also extensively reviewed the literature on the immunohistopathological and radiological differential diagnosis of clival lesions.

Rare Case of Solitary Nasal Fibrous Tumor Eroding Skull-Base

Solitary fibrous tumor (SFT) is a spindle cell lesion, classified under mesothelial tumors. Involvement of the nasal cavity, paranasal sinuses, and nasopharynx is rare. We present an extremely rare case of SFT of nasal origin eroding the anterior skull base. Complete local excision is the treatment of choice in the head and neck SFT, and we successfully excised the tumor by endoscopic approach only. The patient followed an uneventful course without any evidence of recurrence on 8-months follow-up.

Malignant Solitary Fibrous Tumor of the Right Cerebellum: A Case Report

Solitary fibrous tumor is a very rare mesenchymal tumor that occurs mostly in the pleura, and there are few reported cases of a presence in the central nervous system, particularly in the cerebellum. In 2016, the WHO classified solitary fibrous tumors into grade I. In this article, we present a case of malignant solitary fibrous tumor recurring 8 years after surgery in a 63-year-old male. Magnetic resonance imaging showed low to intermediate mixed signal intensity on T1W1. Immunohistochemical staining positivity for Vimentin, CD99, CD34 and Bcl-2, it is consistent with the immunohistochemical characteristics of solitary fibrous tumor. We resected the patient's tumor, and the patient was followed up for 3 months with no signs of recurrence. Solitary fibrous tumors are very rare in the central nervous system. Immunohistochemical staining positivity for CD34 and Bcl-2 is strongly expressed in most solitary fibrous tumor. Surgical resection is the preferred treatment. Due to the small number of cases, the biological behavior and prognosis of this tumor need to be further explored.

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.

Spinal Intramedullary Solitary Fibrous Tumor: A Rare and Challenging Diagnosis

Background

Solitary fibrous tumor (SFT) is a benign neoplasm arising in the soft tissue, which can occur anywhere in the body, while it is predominantly found in the visceral pleura. Spinal SFT is quite uncommon, with limited cases having been reported in the literature; especially, SFT occurring in the intramedullary site is extremely rare.

Case presentation

We present a case of a 35-year-old woman presenting with progressive numbness and weakness in the legs and urinary incontinence. Magnetic resonance imaging (MRI) showed an intramedullary lesion with bright enhancement. A diagnosis of spinal hemangioblastoma was suspected, and thus a three-dimensional computed tomographic angiography reconstruction was requested, which also demonstrated an angiomatous lesion. The tumor was completely resected under neurophysiological monitoring. However, histopathological and immunohistochemical examinations revealed an SFT. No adjuvant radiotherapy or chemotherapy was scheduled. The symptoms were relieved completely, and no recurrence or progression was noted during the follow-up.

Conclusion

Though SFT has been considered similar to malignant hemangiopericytoma and the histological classification has always been controversial, the intramedullary location and benign behavior in the present case add to the current understandings of this extremely rare entity.

Extremely rare case of intravascular solitary fibrous tumour in the inferior vena cava with review of the literature

BACKGROUND

Solitary fibrous tumour (SFT) is a mesenchymal tumour of fibroblastic type, and it develops in almost any part of the human body. However, according to previous studies, the occurrence of intravascular SFTs is extremely rare.

CASE PRESENTATION

We reported a case of intravascular SFT in a 67-year-old woman who has been experiencing swelling and pain in the right leg for 2 months. Computed tomography venography scan revealed a well-defined mass obstructing the inferior vena cava (IVC). Surgical resection was performed, and histopathologic and immunohistochemical results were consistent with SFT. Further, next-generation sequencing (NGS) analysis was performed, and results revealed two tumour-related gene mutations (deletion of PMS2 and variation of ESR1 [L536P]). The patient did not receive any adjuvant therapy, and no signs of tumour progression were observed during the 6-month follow-up.

CONCLUSION

To the best of our knowledge, this study first presented about SFT arising from the IVC and carried out an NGS analysis to validate the molecular mechanism of such condition.

Solitary fibrous tumor of the pineal region with delayed ectopic intracranial metastasis: A case report and review of the literature

RATIONALE

Solitary fibrous tumors of central nervous system are rare spindle-cell mesenchymal tumors. Although most are benign in nature, malignant transformation and extracranial metastasis have been reported. Up to now, only one case of CSF dissemination was described. Here we described an extremely rare case of intracranial Solitary fibrous tumors arising from the pineal region with a delayed ectopic metastasis.

PATIENT CONCERNS

A 35-year-old female presented with double vision, memory disturbance and unsteady gait was referred to our center. MRI showed an irregular mass in the pineal region.

DIAGNOSES

The patient was diagnosed as pineal tumor, with unknown pathology.

INTERVENTIONS

Gross total resection was achieved and the pathologic studies confirmed a solitary fibrous tumor. Thirty-nine months later local recurrence occurred and gamma-knife radiotherapy was offered. Seven months later, MRI found a metastasis in the left temporal lobe. Surgical resection was conducted and pathological analysis revealed changes in cell morphology, counts and Ki-67 level, confirmed the diagnosis of solitary fibrous tumor/hemangiopericytoma (WHO Grade III). The patient received post-operational radiotherapy.

OUTCOMES

The patient was followed up for 7 months with no signs of recurrence.

LESSONS

Here, we report an extremely rare case of primary solitary fibrous tumor of pineal region with delayed intracranial ectopic metastasis, together with literature review of metastatic solitary fibrous tumors. Strict surveillance is strongly recommended, considering the malignant potential of this seemingly benign disease entity. Complete resection of the tumor is the treatment of first choice and radiotherapy might be an effective adjuvant therapy for high grade SFT/HPCs.

Primary intrapulmonary solitary fibrous tumours

Due to the extreme rarity of primary intrapulmonary solitary fibrous tumours (SFTs), their clinical course, imaging characteristics, diagnosis, treatment and prognosis are poorly understood. The present study therefore assessed the diagnosis and management of primary intrapulmonary SFTs and systematically reviewed previously reported cases in the literature. A total of 5 patients who underwent resection for primary intrapulmonary SFTs were enrolled in the present study and their clinical course, tumour characteristics, management and survival were assessed in this retrospective study. Relevant studies regarding primary intrapulmonary SFTs were searched using PubMed and tumour characteristics, clinicopathologic features, therapeutic strategy and survival outcomes were reviewed. Of the 5 cases, all were males, with a mean age of 57.6 years (range, 37-68 years). All patients were asymptomatic and were identified incidentally on routine computed tomography examination. A total of 3 patients underwent thoracotomy and 2 patients underwent video-assisted thoracoscopic surgery. All tumours were completely resected. Postoperative haemorrhage occurred in 1 patient and he received surgical intervention for haemostasis. The average hospital stay was 15 (4-22) days, and no mortality occurred. The mean length of the postoperative follow-up was 37.6 (1-67) months. One patient was lost to follow-up, and 4 patients were asymptomatic. A total of 19 studies were identified from database searches. They included a total of 45 patients: Twenty-three males and 22 females (mean age, 59.4 years; range, 7-81 years). A total of 12 patients were asymptomatic, and pain and coughing were the major symptoms. Five, one, two, four, and 17 tumours occurred in the right upper lobe, right middle lobe, right lower lobe, left upper lobe and left lower lobe, respectively. A total of 39 patients underwent surgery, 1 patient underwent radiotherapy, and 1 patient underwent radiofrequency ablation. A total of 22 patients were followed up and the mean length of the postoperative follow-up was 48 (1-168) months. One patient was diagnosed with chest wall metastases, and 5 patients succumbed to mortality. To conclude, primary intrapulmonary SFTs are extremely rare and typically identified incidentally. The present findings indicated that the left lower lobe was the most common site location and complete surgical resection is a safe and effective treatment.