Neurosurgery notes/Tumours/Mesenchymal non meningothelial tumours/Soft tissue tumors/Hemangiomas and vascular malformations

Hemangiomas and vascular malformations

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Soft tissue tumors

General

  • Consist of
    • Haemangiomas are benign neoplastic vascular lesions containing multiple tightly packed capillary-sized and cavernous vessels.
    • Cavernous malformations (CMs) are angiographically occult vascular anomalies consisting of multiple tightly packed sinusoidal vessels with fibrotic walls and little to no interposed CNS tissue.
    • Arteriovenous malformations (AVMs) are fast-flow vascular anomalies consisting of arteriovenous connections through a nidus or fistula of malformed arteries and veins rather than a normal capillary bed.
    • Capillary telangiectasia is an aggregation of individually dispersed dilated capillary-type vessels with normal brain parenchyma interspersed between them.

Vertebral haemangiomas

General

  • Benign tumours vary in size
  • Are the most common primary spinal tumours

Definition

  • Essential: Tightly packed capillary-sized and cavernous vessels lined by a single layer of benign endothelial cells, set in a mesenchymal stroma with fibroblasts, and an absence of foamy stromal cells.

WHO Grade

  • benign lesions

Numbers

  • Vertebral haemangiomas have a prevalence of 10-12 percent in the general population.

Localisation

  • Most are primary lesions of bone that impinge on the CNS
    • Thoracic and Lumbar vertebrae
  • Dural and parenchymal lesions are less common
  • Less frequently in the skull.

Histopathology

Macrosopic

  • Haemangiomas are soft, red, and lobular masses associated with small feeder and drainer vessels.
Capillary haemangioma. Reddish-brown sponge-like appearance of an intraosseous capillary haemangioma on cut surface of a skull resection specimen.
Capillary haemangioma. Reddish-brown sponge-like appearance of an intraosseous capillary haemangioma on cut surface of a skull resection specimen.
 

Microscopic

  • Haemangiomas show a lobular pattern separated by fibrous septa;
  • Vessels range from small, poorly canalized channels to blood-filled cavernous spaces.

Immunophenotype Features:

  • In haemangiomas, endothelial cells express ERG, CD31, and CD34, and the Ki-67 index is usually less than 10 percent.

Pathogenesis

  • Haemangiomas may be part of a PIK3CA-related overgrowth syndrome, such as Klippel-Trenaunay syndrome.

Imaging

  • Usually incidental lesions
  • MRI
    • Characteristically demonstrates high signal on both T1- and T2
  • CT
    • Larger lesions demonstrate the characteristic ‘honeycomb’ appearance or ‘corduroy sign’ on sagittal and coronal CT, which are prominent vertical striations of thickened trabecular bone.
Images
Haemangioma. (A) Axial computed tomography (CT) scan image showing multiple punctate areas of sclerosis creating the white polka-dot sign. (B) Coronal and (C) sagittal reconstructed CT images displaying prominent vertical trabecula of corpus of the D12 vertebra resembling a honeycomb and forming the ‘corduroy’ sign. (D) Sagittal T1-weighted and (E) sagittal T2-weighted magnetic resonance images demonstrating two haemangiomas at the D12 and L1 vertebrae with high signal intensity (arrows).
Haemangioma. (A) Axial computed tomography (CT) scan image showing multiple punctate areas of sclerosis creating the white polka-dot sign. (B) Coronal and (C) sagittal reconstructed CT images displaying prominent vertical trabecula of corpus of the D12 vertebra resembling a honeycomb and forming the ‘corduroy’ sign. (D) Sagittal T1-weighted and (E) sagittal T2-weighted magnetic resonance images demonstrating two haemangiomas at the D12 and L1 vertebrae with high signal intensity (arrows).
Haemangioma. Exophytic mass affecting posterior aspect of vertebral bodies and posterior elements is shown on T1 (A) and T2 (B) sagittal MRI (arrows). Axial MRI before (C) and after (D) contrast show intense enhancement of the haemangioma with substantial compression of the thecal sac (arrows).
Haemangioma. Exophytic mass affecting posterior aspect of vertebral bodies and posterior elements is shown on T1 (A) and T2 (B) sagittal MRI (arrows). Axial MRI before (C) and after (D) contrast show intense enhancement of the haemangioma with substantial compression of the thecal sac (arrows).

Clinical features

  • Vertebral haemangiomas mainly asymptomatic
  • Small proportion of these tumours may expand the bone and cause pathological fractures, or extend into the epidural space and compress neural structures.

Treatment

  • Indicated for symptomatic lesions only
  • Surgical excision, vertebroplasty, endovascular embolisation, and radiotherapy.

Prognosis

  • Haemangiomas usually do not recur after complete resection.