Resection and postoperative pazopanib for intraspinal recurrent solitary fibrous tumor: illustrative case

Abstract

BACKGROUND

Intracranial solitary fibrous tumors (SFTs) rarely recur in the spinal space. Only 4 cases of spinal recurrence from intracranial SFT have been reported; therefore, the optimal treatment of recurrent spinal SFT remains unclear.

OBSERVATIONS

A 53-year-old woman with a history of resection of a right occipital anaplastic SFT presented with progressive back and side pain. She was diagnosed with an intradural extramedullary tumor ventral to the spinal cord at the T5–7 level. She underwent tumor resection with T5–6 laminectomy and T4 and T7 partial laminectomy. The tumor was completely removed in a piecemeal fashion using an ultrasonic aspirator with careful control of bleeding. Her symptoms quickly improved after the surgery, and she returned to normal life. The tumor was diagnosed as SFT. Pazopanib was administered postoperatively. Despite the recurrence of the intracranial tumor, the patient was alive without recurrence of the spinal tumor 14 months after resection.

LESSONS

Although rare, intracranial SFTs have a risk of spinal recurrence. Complete resection of a recurrent spinal SFT can be achieved even in the ventral location. Pazopanib could be a possible therapeutic option for preventing local tumor recurrence in the management of recurrent spinal SFT.

https://thejns.org/doi/10.3171/CASE24217

Solitary fibrous tumors (SFTs) are uncommon neoplasms that frequently affect the abdominal cavity, retroperitoneum, mediastinum, soft tissues, leptomeninges, and orbit.¹ They rarely involve the liver, lungs, gastrointestinal tract, pancreas, adrenal glands, bladder, prostate, testis, thyroid, and salivary glands.¹ SFTs have been characterized by the genetic hallmark of fusion between the NGFI-A-binding protein 2 (NAB2) and signal transducer and activator of transcription 6 (STAT6) genes.^{1, 2}

Meningeal SFTs account for 0.5%–1% of all tumors of the central nervous system (CNS).^1–3 In the CNS, tumors are more commonly found in the cranial cavity, and spinal involvement is rare, accounting for only 10% of intracranial SFTs.² Resection is the first step in the treatment and diagnosis of intracranial SFT, and radiotherapy is an important adjunct to surgery, particularly when gross-total resection is not achieved.⁴ Despite the combination of surgery and adjuvant radiotherapy, SFTs frequently recur locally and in extraneural sites, with 5-year recurrence rates ranging from 20% to 70%.⁴ Common sites of extraneural recurrence include the bones, liver, lungs, and abdominal cavity.^{4, 5} However, intracranial SFTs recurring in the spinal space are extremely rare, and only 4 cases have been reported in the literature.^6–9

Here, we report a case of spinal recurrence of an intracranial SFT treated with resection and postoperative pazopanib.

Illustrative Case

A 53-year-old woman presented with a 2-week history of progressive back and side pain. Her pain was severe, requiring opioids. Spinal magnetic resonance imaging (MRI) at presentation revealed an intradural extramedullary lesion at the T5–7 level (Fig. 1A–C). The tumor was located ventral to the spinal cord with heterogeneous enhancement (Fig. 1A–C). Head MRI also showed a small mass lesion attached to the left temporal dura (Fig. 1D).

FIG. 1.

Preoperative sagittal T2-weighted (A) and gadolinium-enhanced T1-weighted (B) images showing a T5–7 intradural extramedullary tumor (white arrows) located ventral to the spinal cord. Preoperative axial gadolinium-enhanced T1-weighted image (C) showing a tumor (white arrow) located left and ventral to the spinal cord (white arrowhead). Axial head gadolinium-enhanced T1-weighted image (D) showing a tumor attached to left temporal dura (black arrowhead).

She had a history of right occipital anaplastic SFT (Fig. 2A), which had been resected completely via surgery (Fig. 2B), and had received stereotactic radiotherapy of 30 Gy in 5 fractions 6 years earlier. She underwent a second surgery for suspected local tumor recurrence 34 months after the initial surgery. However, radiation necrosis was diagnosed. She experienced repetitive tumor recurrence after the second surgery in the right cerebellum 5 months later (Fig. 2C); in the right frontal falx and left parietal falx (Fig. 2D) and left temporal tip 9 months later; in the right cerebellum and left clivus 18 months later (Fig. 2E); and in the right cavernous sinus 29 months later (Fig. 2F). All were attached to the dura mater and were supposed to be disseminated. All these dural lesions were successfully controlled with stereotactic radiotherapy at the presentation of the spinal tumor. Based on this history, the preoperative diagnosis of the spinal tumor was a recurrence of the intracranial SFT.

FIG. 2.

Preoperative (A) and postoperative (B) axial gadolinium-enhanced T1-weighted images showing a right occipital tumor. Axial gadolinium-enhanced T1-weighted images showing repetitive tumor recurrence (white arrows) in the right cerebellum (C), right frontal and left parietal falx (D), right cerebellum and left clivus (E), and right cavernous sinus (F).

Tumor resection was performed with a T5–6 laminectomy and T4 and T7 partial laminectomy, with the monitoring of motor and sensory evoked potentials. After a dural incision, the tumor was observed behind the dentate ligament to the left of the spinal cord (Fig. 3A, Video 1). Resection of the dentate ligament allowed tumor exposure and provided a surgical space. The tumor demonstrated a bleeding tendency, necessitating meticulous coagulation. Initially, the tumor was debulked from the narrow surgical space between the spinal cord and the edge of the dura using an ultrasonic aspirator. As tumor removal proceeded, the bleeding was reduced, and the surgical space was created. The tumor was removed in a piecemeal fashion using an ultrasonic aspirator (Fig. 3B). Total tumor removal was achieved because the tumor did not invade the spinal cord (Fig. 3C).

FIG. 3.

Intraoperative photographs. A: A reddish tumor (white arrow) was observed behind the dentate ligament to the left of the spinal cord. B: The tumor (white arrow) was debulked and removed in a piecemeal fashion. C: Total tumor removal was successfully achieved.

VIDEO 1. Clip showing the resection procedure. After the dural incision, the tumor was observed behind the dentate ligament to the left of the spinal cord. The dentate ligament was dissected to confirm the caudal end of the tumor. The tumor showed a bleeding tendency, necessitating meticulous coagulation. Tissue sampling was performed. The bleeding tendency of the tumor was observed. The tumor was debulked using an ultrasonic aspirator from the narrow surgical space. As the tumor removal proceeded, the bleeding was reduced, and finally, the ventral dura was observed. An ultrasonic aspirator easily aspirated the soft yellowish tumor. The tumor was removed from the left nerve root. The rostral part of the tumor was removed. The caudal part of the tumor was resected from the left nerve root. The caudal part of the tumor was aspirated and removed. The tumor was completely removed. Click here to view.

Postoperative MRI confirmed complete removal of the tumor (Fig. 4A). Pathological analysis revealed SFT consisting of haphazardly arranged monomorphic cells with focal myxoid stroma (Fig. 4B). The tumor cells were immunopositive for STAT6 (Fig. 4C).

FIG. 4.

A: Postoperative sagittal gadolinium-enhanced T1-weighted image showing total removal of the tumor. B: Hematoxylin and eosin staining showing the tumor consisting of haphazardly arranged monomorphic cells with focal myxoid stroma. Mitotic activity was > 2.5 mitoses/mm² (inset, original magnification ×400). C: Tumor cells showing immunopositivity for STAT6 (original magnification ×100). DandE: Axial gadolinium-enhanced T1-weighted images showing tumor recurrence (white arrows) in the left frontal falx and right jugular foramen.

The patient’s back and side pain quickly improved after surgery. Pazopanib was administered 2 weeks postoperatively. The tumor attached to the left temporal dura was treated with stereotactic radiosurgery of 20 Gy in 1 fraction and was controlled for 14 months after spinal tumor resection. She had intracranial tumor recurrence 11 months after the spinal surgery (Fig. 4D and E), and she received stereotactic radiotherapy. The pazopanib dose was reduced because of diarrhea and nausea, but the patient had a normal life without recurrence of the spinal tumor 14 months after resection.

Patient Informed Consent

The necessary patient informed consent was obtained in this study.

Discussion

Observations

Our case demonstrates that intracranial SFT can recur in the intradural spinal space, although this is rare. Only 4 cases have been reported in the English-language literature (Table 1).^6–9 There were 3 females and 1 male, who were middle aged at diagnosis. Their primary tumor location included the cerebellum, tentorium, cerebellopontine angle, and frontal lobe, while the recurrent spinal tumor locations included the thoracic spine in 2 patients and the lumbosacral spine in 2 patients. All patients underwent surgery for the recurrent spinal tumor. Although complete resection was achieved in 2 patients,^{7, 8} the remaining 2 patients underwent partial or subtotal resection due to the high bleeding tendency or invasion of the spinal cord.^{6, 9} Postoperative treatment included radiation therapy for 3 cases^{6, 7, 9} and no adjuvant therapy for 1 case.⁸ However, postoperative systemic therapy has not been reported. Our case is unique, as it describes the successful resection of a ventral recurrent spinal SFT through the posterior approach and the potential benefit of postoperative pazopanib in preventing local tumor recurrence.

TABLE 1.

Summary of 5 cases of intradural spinal recurrence from intracranial SFT

Authors & Year	Age (yrs)	Sex	Primary Tumor Location	Duration (yrs)	Spinal Tumor Location	Symptom	Extent of Resection	Adjuvant Therapy (dose)	Clinical Outcome
Taniura et al., 20079	34	F	Cerebellum	4	L4–S1	Pain, motor weakness, urinary urgency & frequency	Partial resection	Whole-spine radiation therapy (50 Gy)	No recurrence for 1 yr
Ali et al., 20166	53	F	Tentorium	6	T11–12, dorsal	Gait disturbance	Subtotal resection	Whole-spine radiation therapy (50.4 Gy)	No recurrence for 14 mos
Hayenga et al., 20197	34	F	Cerebellopontine angle	3	T3–4, ventral	No symptom	Total resection	Local radiation therapy (45 Gy)	No recurrence for 6 mos
Tang et al., 20198	53	M	Frontal lobe	Simultaneous	S1–2	Back pain	Total resection	No adjuvant therapy	Recurrence of intracranial tumor 5 mos postop, unknown of intraspinal tumor
Current case	53	F	Occipital lobe	2.8	T5–7, ventral	Back & side pain	Total resection	Pazopanib	No spinal recurrence for 14 mos, recurrence of intracranial tumor 11 mos postop

There is no consensus on the optimal treatment for spinal recurrence of intracranial SFT because of its rarity.^{6, 9} Surgery is the mainstay of treatment, especially for symptomatic cases, because it effectively alleviates myelopathy or radiculopathy through tumor resection. However, resection of spinal SFT is challenging due to its high vascularity, invasive nature, and narrow surgical space.^{2, 6, 9} For primary spinal SFT, gross-total resection was achieved for 71% of cases, with reasons for subtotal resection including spinal cord invasion and excessive bleeding.² In our case, the tumor was located ventral to the spinal cord, but it was completely removed using the posterior approach despite the narrow surgical space (Video 1). Intraoperatively, careful bleeding control via coagulation and dissection of the tumor from nerve roots made complete resection possible. Ultrasonic aspiration was also useful in debulking the tumor from the narrow surgical space. After successful complete resection, the patient’s back pain improved rapidly. Our case suggests that resection should be considered even for tumors in ventral locations in symptomatic cases.

Radiotherapy can be administered after subtotal resection to prevent local recurrence in the primary setting.² However, radiotherapy has not been proven to have a survival benefit and has been associated with the risk of developing radiation myelopathy.² Moreover, spinal recurrence from intracranial SFT is suggestive of cerebrospinal fluid dissemination, which needs whole-spine radiation.^{6, 9} Concerns about the uncertainty of effectiveness and the risk of whole-spine radiation therapy, including radiation necrosis or myelosuppression, were the primary reasons for not indicating radiation therapy in our case.

Conventional chemotherapy has a limited clinical benefit for SFT.^{2, 10} SFTs are characterized by an NAB2::STAT6 fusion, which induces insulin-like growth factor–1 overexpression and angiogenesis in the tumor microenvironment.¹¹ SFTs also show high expression of vascular endothelial growth factor and platelet-derived growth factor receptor.¹⁰ Antiangiogenic therapies such as pazopanib are, therefore, promising therapeutic options. Apra et al. reported a dramatic clinical and radiological response to pazopanib in 2 patients with intracranial recurrent SFTs, suggesting the efficacy of pazopanib for treating CNS SFT.¹² Ebata et al. reported that 9 cases of recurrent or metastatic SFT, including 2 cases with intracranial SFTs, were treated by pazopanib, showing a high disease control rate with 88.9%.¹⁰ This result suggested that pazopanib was effective for recurrent or metastatic SFT. In our case, spinal tumor recurrence was not observed 14 months after the initiation of pazopanib therapy, suggesting that postoperative pazopanib may be a therapeutic option in preventing local tumor recurrence in the management of recurrent spinal SFT.

One of the major limitations of this study is that the efficacy of pazopanib treatment is not completely concluded because intracranial disseminated tumor recurrence was observed during pazopanib treatment. Further studies are needed to confirm the efficacy of pazopanib in patients with intracranial SFTs and spinal recurrence.

Lessons

First, intracranial SFTs have a risk of intradural spinal recurrence, although rare. Clinicians should be mindful of the symptoms such as back and side pain during the clinical course and perform radiological examinations. Second, resection of spinal recurrent SFT can be achieved even for the ventral location with cautious control of intraoperative bleeding. Resection is beneficial for the rapid alleviation of the symptoms of the patient. Third, postoperative systemic therapy, such as pazopanib, is a promising therapeutic option for preventing local tumor recurrence in the management of recurrent spinal SFT.

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author Contributions

Conception and design: Ohno, Narita. Acquisition of data: Yoshida, Yanagisawa. Analysis and interpretation of data: Ohno, Sugino, Yoshida. Drafting the article: Ohno. Critically revising the article: Kawaguchi, Sugino, Yoshida, Takahashi, Yanagisawa, Osawa, Tsuchiya, Fujita. Reviewed submitted version of manuscript: Ohno, Kawaguchi, Sugino, Yoshida, Yanagisawa, Osawa, Tsuchiya, Fujita, Narita. Approved the final version of the manuscript on behalf of all authors: Ohno. Administrative/technical/material support: Yanagisawa. Study supervision: Narita.

Supplemental Information

Videos

  Video 1. https://vimeo.com/949938131.

Correspondence

Makoto Ohno: National Cancer Center Hospital, Chuo-ku, Tokyo, Japan. mohno@ncc.go.jp.