Abstract
BACKGROUND
Pseudomyogenic hemangioendothelioma (PMHE) is a rare vascular tumor with intermediate malignant potential, most commonly affecting young males and typically involving the soft tissues of the lower extremities. Spinal involvement is exceedingly rare, particularly as an isolated bony lesion without soft tissue extension, posing challenges in establishing standardized treatment approaches.
OBSERVATIONS
This report details a unique case of thoracic PMHE in a 60-year-old woman managed with a multistaged surgical approach, including preoperative embolization and en bloc spondylectomy. The authors describe the patient’s clinical presentation, radiographic findings, surgical technique, and postoperative course, highlighting the role of en bloc resection in achieving tumor control.
LESSONS
This case underscores the feasibility of aggressive surgical management for spinal PMHE and emphasizes the need for further research to refine optimal treatment strategies.
Keywords: en bloc spondylectomy, pseudomyogenic hemangioendothelioma, thoracic spine
ABBREVIATIONS: GTR = gross-total resection, PMHE = pseudomyogenic hemangioendothelioma
Pseudomyogenic hemangioendothelioma (PMHE) is a rare vascular tumor with intermediate malignant potential. Predominantly affecting young males, it usually presents in the soft tissues of the lower extremities.1 PMHE can involve various regions, but spinal involvement is exceedingly rare, especially without soft tissue extension.2–5 The limited number of spinal cases hinders the development of standardized treatment protocols. This report describes a unique case of PMHE presenting as a thoracic lesion, managed with preoperative embolization and a staged en bloc spondylectomy. The CARE guidelines were followed in this study.
Illustrative Case
A 60-year-old woman presented with focal thoracic back pain. Her neurological examination was unremarkable. MRI revealed a T1 hypointense, T2 hypointense heterogeneous mass in the T12 vertebral body without postcontrast enhancement, extending into the right pedicle without dural or spinal cord involvement (Fig. 1A). CT imaging demonstrated lytic lesions with sclerotic changes (Fig. 1B). A percutaneous biopsy confirmed PMHE. Staging workup revealed no additional lesions. A multistaged surgical approach was planned, beginning with endovascular embolization to minimize intraoperative blood loss, followed by en bloc spondylectomy with corpectomy cage placement and T10–L2 posterior instrumented fusion.
FIG. 1.
A: MR image revealing a T1 hypointense, T2 hypointense heterogeneous mass in the T12 vertebral body without postcontrast enhancement, extending into the right pedicle without dural or spinal cord involvement. B: CT scan showing lytic lesions within the sclerotic T12 vertebral body.
Spinal angiography identified branches of the T12 segmental intercostal arteries supplying the tumor, which were embolized with N-butyl cyanoacrylate, achieving tumor devascularization (Fig. 2). The first surgery involved a lateral thoracic approach. After deflation of the left lung to avoid injury to thoracic structures, the vascular surgery team assisted in exposing the T12 vertebral body via an extraperitoneal route. Image guidance confirmed T11–12 and T12–L1 disc spaces. The lumbar arteries and veins were divided at T12, and the great vessels were mobilized anteriorly. Standard discectomies were completed, and Duragen (Integra LifeSciences) was placed between the anterior T12 vertebral body and great vessels to protect the vasculature and serve as a visual landmark for the anterior margin of the vertebral body during posterior dissection. The purpose of this initial anterior/lateral approach was to create a safe avascular plane between the vertebral body and great vessels, minimizing the risk of vascular injury during subsequent posterior en bloc resection and ensuring oncologic margins were preserved. The diaphragm and pleura were repaired without complications.
FIG. 2.
A and B:Spinal angiograms showing 1 medially directing branch of the right T12 segmental intercostal artery filling the tumor blush within T12 vertebral body (A) and 2 medially directing branches of the left T12 segmental intercostal artery supplying a dilated venous structure in the T12 vertebral body (B). C: Postembolization angiogram showing no anterograde filling of the tumor blush or dilated venous structure within the T12 vertebral body.
The next day, en bloc spondylectomy and posterior fusion were performed. Pedicle screws were bilaterally placed from T10 to L2 using image guidance, with a temporary rod inserted on the left side. En bloc spondylectomy and laminectomy of the T12 vertebra were performed using high-speed drills and Kerrison rongeurs. An ultrasonic scalpel facilitated the right costotransversectomy, providing access to the anterior vertebral body. Duragen was identified, and a large malleable retractor was inserted into this plane to protect the anterior vascular structures, while an osteotome was used to remove the bilateral pedicles and facet joints. The exiting T12 nerve roots were ligated, and the dura was released from the posterior aspect of the T12 vertebra. Posterior discectomies at T11–12 and T12–L1 were then performed to free the T12 vertebral body. With careful rotation, the vertebral body was removed en bloc and sent for histopathological analysis. The anterior arthrodesis was achieved using a Globus corpectomy cage filled with demineralized bone matrix and anterior spine reconstructed with this cage filled with allograft that was placed and expanded under direct fluoroscopy. Posterolateral arthrodesis was performed by fixating pedicle screws within rods followed by decortication of transverse processes and laminae of T10, T11, L1, and L2 and placing Fibergraft Aeridyan matrix, a synthetic bone graft substitute, within the posterolateral gutters from T10 to L2. An illustration of key surgical steps is shown in Fig. 3.
FIG. 3.
Key surgical steps. A: Black lines indicate osteotomy sites for en bloc spondylectomy, with the vena cava (blue), aorta (red), spinal cord (yellow), and vertebral tumor (star) represented. B: Sequence of osteotomy and release of posterior bony articulations, with posterior osteotomies (1) performed first, followed by anterior osteotomies (2). C: Vertebral body removal with protection of vessels using a malleable retractor (blue) and the direction of movement (arrow).
The patient was monitored in the ICU postoperatively. No acute complications were noted. She was discharged to a rehabilitation facility on day 13, with extended stay attributed to pain control and socioeconomic factors. At 1 month postoperatively, a seroma at the surgical site was evacuated with drain placement. By 6 months, the seroma had resolved with no evidence of pseudarthrosis and the patient had gradual improvement in back pain with physical therapy. CT and MRI performed at 20 months postoperatively demonstrated expected bony fusion across the corpectomy cage and no evidence of local tumor recurrence (Fig. 4). At nearly 2 years postoperatively, the patient continues to experience thoracic back pain; however, it remains stable and is manageable with conservative treatment.
FIG. 4.
Images obtained at the 20-month postoperative follow-up, demonstrating bony fusion through corpectomy cage on sagittal (A) and coronal (B) CT scans, and no evidence of local tumor recurrence on sagittal (C) and axial (D) MR images.
Informed Consent
The necessary informed consent was obtained in this study.
Discussion
Observations
PMHE is a rare, vascular neoplasm first described by Hornick and Fletcher in 2011 as an intermediate-grade malignancy with a tendency for multifocal soft tissue involvement and local aggression across multiple tissue planes.6 PMHE typically presents in young adult males, most commonly affecting the lower extremities. Isolated osseous involvement, particularly in the spine, is exceedingly rare, with only a limited number of cases reported in the literature.2–5,7
This case describes an unusual presentation of PMHE confined to the T12 vertebral body, without soft tissue extension, adding to the scarce literature on spinal manifestations of this entity. The lesion demonstrated imaging features consistent with other reported cases of skeletal PMHE, hypointense on T1- and T2-weighted MRI, with lytic characteristics and sclerotic margins on CT imaging. Histopathological confirmation remains essential, as PMHE can mimic other vascular or epithelioid neoplasms.
PMHE carries a high propensity for local recurrence, with rates reported up to 58%, although metastatic spread is rare.6 Given its locally aggressive nature, gross-total resection (GTR) remains the cornerstone of treatment, especially in osseous cases. Preoperative embolization has been used in similar vascular tumors to mitigate intraoperative bleeding and was used in this case to achieve tumor devascularization prior to spondylectomy,7 reducing blood loss to 1.9 L during stage 1 and 600 mL during stage 2. A two-stage approach was selected to minimize manipulation of the tumor-bearing vertebra during resection. The first stage allowed controlled release of anterior soft tissue attachments and adjacent disc spaces, facilitating placement of Duragen between the vertebral body and great vessels. This enabled safer mobilization during the posterior en bloc resection. The second stage included image-guided posterior instrumentation and vertebral body removal. Intraoperative navigation was used to assist with anatomical orientation. The decision to stage the procedure also accounted for the length and complexity of the surgery and was discussed thoroughly with the patient, including the associated risks, recovery expectations, and the rationale for an en bloc strategy. Emerging targeted therapies, including rapamycin inhibitors such as everolimus, have shown promise in select cases, although their long-term efficacy remains uncertain.8,9
Lessons
Due to the rarity of spinal PMHE, standardized treatment guidelines are lacking, and management decisions are often extrapolated from treatment principles applied to other spinal tumors. Prior case reports have documented vertebroctomy and costotransversectomy, often supplemented with adjuvant radiotherapy, but long-term outcomes remain unclear.2–5,7 En bloc spondylectomy is widely regarded as the preferred approach for malignant and locally aggressive spinal tumors, including chordomas and chondrosarcomas, as it maximizes tumor resection and minimizes recurrence risk.10 Compared with piecemeal resection techniques such as vertebrectomy or vertebral column resection, en bloc spondylectomy minimizes the risk of tumor cell dissemination by preserving oncological margins and avoiding intralesional disruption. In other intermediate-grade vascular tumors, en bloc resection has been associated with reduced local recurrence, although comparative data remain limited in PMHE.11,12 However, en bloc resection is associated with significant morbidity, including an estimated 35% complication rate and 2% mortality rate.13 Despite these risks, our case demonstrated the feasibility of en bloc spondylectomy in achieving gross total resection of spinal PMHE, reinforcing its role as a potentially curative intervention in carefully selected patients.
Given the high recurrence risk even after GTR, close postoperative surveillance remains essential. Serial imaging is necessary to monitor for local recurrence, and adjuvant therapy should be considered in cases with positive margins. As spinal PMHE remains poorly characterized, further case accumulation and long-term follow-up studies are needed to establish standardized treatment guidelines and refine management strategies.
This case highlights the rare presentation of PMHE as an isolated spinal lesion and demonstrates the feasibility of en bloc spondylectomy with preoperative embolization as a treatment strategy. Despite the high recurrence risk associated with PMHE, GTR was achieved, underscoring the importance of a multidisciplinary approach in optimizing surgical outcomes. Given the limited data on spinal PMHE, continued case reporting and long-term follow-up are essential to refine management strategies and improve patient outcomes.
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: Mehta, Peng, Sadeh. Acquisition of data: Mehta, Peng, Sadeh, Abou-Mrad. Analysis and interpretation of data: Mehta. Drafting the article: Mehta, Peng, Pearce, Sadeh, Abou-Mrad. Critically revising the article: Mehta, Peng, Pearce, Sadeh, Abou-Mrad. Reviewed submitted version of manuscript: all authors. Approved the final version of the manuscript on behalf of all authors: Mehta. Administrative/technical/material support: Mehta, Peng, Borhani.
Correspondence
Ankit Mehta: University of Illinois Chicago, IL. ankitm@uic.edu.
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