
==== Front
J Neurosurg Case Lessons
J Neurosurg Case Lessons
J Neurosurg Case Lessons
Journal of Neurosurgery: Case Lessons
2694-1902
American Association of Neurological Surgeons

39186826
10.3171/CASE24265
CASE24265
SpineSpineCase Lesson
Novel case of anastomosing hemangioma of the extradural space: illustrative case
Fujita Shohei MD 1
Ohno Makoto MD, PhD 1
Osaki Shuhei MD, PhD 2
Sugino Hirokazu MD, PhD 3
Yoshida Akihiko MD, PhD 3
Takahashi Masamichi MD, PhD 1
Yanagisawa Shunsuke MD, PhD 1
Osawa Sho MD, PhD 1
Tsuchiya Takahiro MD 1
Narita Yoshitaka MD, PhD 1
1 Departments of Neurosurgery and Neuro-Oncology, National Cancer Center Hospital, Tokyo, Japan
2 Departments of Musculoskeletal Oncology and Rehabilitation, National Cancer Center Hospital, Tokyo, Japan
3 Departments of Diagnostic Pathology, National Cancer Center Hospital, Tokyo, Japan
Correspondence Makoto Ohno: National Cancer Center Hospital, Tokyo, Japan. mohno@ncc.go.jp.
INCLUDE WHEN CITING Published August 26, 2024; DOI: 10.3171/CASE24265.

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

26 8 2024
26 8 2024
8 9 CASE2426522 4 2024
13 6 2024
© 2024 the authors
2024
the authors
https://creativecommons.org/licenses/by-nc-nd/4.0/ CC BY-NC-ND 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

BACKGROUND

Anastomosing hemangiomas are benign vascular neoplasms occurring mainly in the genitourinary tract and paraspinal soft tissues. There have been no reported cases of anastomosing hemangiomas occurring in the spinal epidural space; therefore, their clinical and radiological presentations remain unclear.

OBSERVATIONS

A 55-year-old man presented with progressive back pain and motor and sensory disturbances in both lower extremities. Magnetic resonance imaging (MRI) revealed an extradural lesion at the T4–6 level that extended into the extraspinal region through the left T5–6 intervertebral foramen. Axial MRI revealed that the tumor encircled the spinal cord, with sharp horn-like ends in the intraspinal canal.

The patient underwent complete tumor resection with T4–6 laminectomy and left T5–6 foraminotomy. The histopathological diagnosis was an anastomo­sing hemangioma exhibiting anastomosing proliferation of capillary vessels with hobnailed endothelial cells. His symptoms improved, and tumor control was achieved 4 months after surgery without adjuvant therapy.

LESSONS

Although rare, anastomosing hemangiomas can occur in the spinal epidural space. Radiologically, the tumors show horn-like projections encircling the spinal cord, which can be diagnostic cues. Anastomosing hemangiomas should be included in the differential diagnosis of spinal epidural tumors, especially when characteristic horn-like projections are present.

https://thejns.org/doi/10.3171/CASE24265

anastomosing hemangioma
spinal epidural space
sharp horn-like projections
angiosarcoma
ABBREVIATIONS

MRI = magnetic resonance imaging.
==== Body
pmcAnastomosing hemangiomas are benign vascular neoplasms characterized by capillary-sized blood vessels with anastomosing architecture, a nonlobular growth pattern, and mild endothelial cell atypia with “hobnail” endothelial cells.1 Montgomery and Epstein first described them in 2009 as rare neoplasms exhibiting histopathological similarities to highly differentiated angiosarcoma in the genitourinary tract. Anastomosing hemangiomas have also been reported to occur in the paraspinal soft tissues and bones,2 adrenal glands,3 ovaries,4 liver,5 gastrointestinal tract,6 larynx,7 and left atrium.8

The spinal epidural space can be affected by a wide range of tumors, including schwannomas,9 meningiomas,10 lymphomas,11 metastatic tumors,12 angiolipomas,13 and cavernous hemangiomas.14–17 In particular, schwannomas and meningiomas often develop in both the intraspinal canal and the extraforaminal space with a “dumbbell” shape.9, 10

Here, we report the case of an anastomosing hemangioma occurring in the spinal epidural space with extension to the extraspinal region that showed strong enhancement, with characteristic sharp horn-like projections encircling the spinal cord on radiological examination.

Illustrative Case

A 55-year-old man presented with a 1-year history of back pain, followed by progressive motor weakness and sensory disturbances in both lower extremities. The patient could walk using a cane. The Babinski reflex was positive on both sides, and the vibration sensation was reduced in both lower extremities.

Magnetic resonance imaging (MRI) at presentation revealed an extradural lesion at the T4–6 level (Fig. 1). The tumor was hypointense on T1-weighted imaging (Fig. 1A) and hyperintense on T2-weighted imaging (Fig. 1B), with homogeneous enhancement on gadolinium-enhanced T1-weighted imaging (Fig. 1C and D). Axial gadolinium-enhanced T1-weighted imaging revealed a strongly enhanced mass posterolaterally encircling the spinal cord, with horn-like sharp ends in the intraspinal canal that extended through the left T5–6 intervertebral foramen to the left paraspinal region near the aorta without bone destruction (Fig. 1D). Our preoperative diagnosis was schwannoma or meningioma based on the tumor’s location in both the intra- and extraspinal canal, although the tumor shape differed from the typical dumbbell shape seen in these tumors. FIG. 1. Preoperative sagittal T1-weighted (A), T2-weighted (B), and gadolinium-enhanced T1-weighted (C) images showing a T4–6 extradural tumor (white arrows) located dorsal to the spinal cord. Preoperative axial gadolinium-enhanced T1-weighted image (D) showing a tumor encircling the spinal cord with sharp horn-like ends (white arrowheads) in the intraspinal canal, extending through the left T5–6 intervertebral foramen to the left paraspinal region near the aorta.

Tumor resection was performed with T4–6 laminectomy and left T5–6 foraminotomy, with monitoring of motor and sensory evoked potentials. The intraspinal portion of the tumor was located in the epidural space and firmly attached to the dura mater. The tumor was dark red and bled easily (Fig. 2). First, the intraspinal portion of the tumor was removed. Bipolar coagulation of the tumor was necessary to control intraoperative bleeding, which shrank the tumor and facilitated dissection of the dura mater. Next, the extraspinal part of the tumor was removed with caution because of the vascular supply from the aorta. Because the tumor did not invade the dura mater or pleura, total tumor removal was successfully achieved. FIG. 2. Intraoperative photograph showing an epidural tumor (arrowheads) that was dark red and bled easily. The tumor was coagulated and detached from the dura.

Postoperative MRI confirmed total tumor removal. The patient did not receive adjuvant therapy, and MRI performed 4 months postoperatively revealed no recurrence (Fig. 3). The patient’s motor function improved in both lower extremities, and he returned to normal activities of daily living. FIG. 3. Postoperative sagittal (A) and axial (B) gadolinium-enhanced T1-weighted images showing complete removal of the tumor (arrowhead).

Pathologically, low magnification showed diffuse vessel growth; higher magnification showed nonlobular architecture and anastomosing proliferation of capillary-sized vessels with mild endothelial cell nuclear variability, scattered hobnailed endothelial cells, and small fibrin thrombi. There were no malignant findings such as cytological atypia, multilayering of endothelial cells, or necrosis (Fig. 4). Based on these findings, the tumor was diagnosed as anastomosing hemangioma. FIG. 4. Hematoxylin and eosin staining showing diffuse vessel growth at low magnification (A) and anastomosing proliferation of capillary-sized vessels with mild endothelial cell nuclear variability, hobnailed endothelial cells (white arrowheads, B), and a small fibrin thrombus. Original magnification ×50 (A), ×200 (B).

Patient Informed Consent

The necessary patient informed consent was obtained in this study.

Discussion

Observations

In this report, we present a rare case of an anastomosing hemangioma in the spinal epidural space that extended into the extraforaminal space. To our knowledge, this is the first reported case of an anastomosing hemangioma affecting this location. In addition to the lesion’s rarity, our case is unique as it reports the horn-like projections encircling the spinal cord on axial MRI that characterize a spinal epidural anastomosing hemangioma, which may be useful in differentiating it from other spinal epidural tumors.

Given the rarity of an anastomosing hemangioma, its preoperative diagnosis is challenging. The differential diagnoses of spinal epidural tumors include schwannomas,9 meningiomas,10 lymphomas,11 metastatic tumors,12 cavernous hemangiomas,14–17 and angiolipomas.13 Schwannomas are usually heterogeneous due to cystic changes and necrosis; they often extend into the paraspinal region, with widening of the intravertebral foramen or bone destruction.9 Meningiomas are typically isointense to the cortex on T1- and T2-weighted imaging and show strong homogeneous enhancement with dural tail signs on postcontrast imaging.10 Lymphomas usually present with an isointense signal on T2-weighted imaging, less frequent paravertebral extension, and intervertebral neural foraminal widening.15 In our case, the tumor showed strong homogeneous enhancement and extended into the intervertebral foramen; the lack of bone changes differentiated it from schwannomas or lymphomas, and the characteristic sharp horn-like projections on axial MRI were not typical of schwannomas, meningiomas, or lymphomas.

Similar sharp horn-like projections encircling the spinal cord can be seen in epidural cavernous hemangioma.14, 17 The characteristic shape of epidural cavernous hemangioma is often described as “lobulated” or “spindle-shaped.”14, 17 Feng et al. suggested that epidural cavernous hemangioma presents with a lobulated spindle shape with 2 tapered ends because the tumor exhibits creeping growth due to its softer texture and the limited epidural space.17 Similar to epidural cavernous hemangiomas, we hypothesized that anastomosing hemangiomas might develop in a crawling fashion through the narrow epidural space, creating a partially spinal cord–encircling shape with sharp ends and characteristic horn-like projections. Anastomosing hemangiomas are difficult to differentiate from cavernous hemangioma on radiological examination. However, they differ from cavernous hemangioma in that they show a nonlobular growth pattern and mild endothelial cell atypia with hobnail endothelial cells. Therefore, histopathological examination is mandatory for an accurate diagnosis.

Angiosarcomas are important differential diagnoses. They are malignant tumors that can occur in the spinal epidural space. Anastomosing hemangiomas differ from angiosarcomas in the absence of local osteolysis and destruction and ill-defined margins on radiological examination.18 Anastomosing hemangiomas can be pathologically differentiated from angiosarcomas by the absence of malignant features such as cytological atypia, multilayering of endothelial cells, and necrosis.1, 2, 18 Clinically, differentiating anastomosing hemangiomas from angiosarcomas is especially important to avoid overtreatment.

Anastomosing hemangiomas have been reported to exhibit benign biological behavior and have an excellent prognosis.19 Therefore, the optimal treatment is merely simple resection.2 Montgomery and Epstein showed no tumor recurrence after nephrectomy or orchiectomy in 6 patients with anastomosing hemangiomas of the genitourinary tract.1 John and Folpe also reported no tumor recurrence in 17 patients with non-genitourinary anastomosing hemangiomas without postoperative adjuvant therapy.2 In our case, we achieved complete resection of both the intra- and extraspinal parts of the tumor and did not observe tumor recurrence for 4 months after the operation without adjuvant treatment.

Lessons

Although extremely rare, anastomosing hemangiomas can occur in the spinal epidural space and extend into the extraforaminal space. The tumor in our case showed horn-like projections encircling the spinal cord on axial MRI, which can be a cue for diagnosis. Anastomosing hemangiomas should be included in the differential diagnosis of spinal epidural tumors, especially in cases where characteristic horn-like projections are seen.

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

Correspondence

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