Makindo Medical Notes.com

Tumour lies within the carotid sheath and so can be moved side to side but not up or down

About

• Tumour from chaemoreceptors at the bifurcation of the carotid artery.
• Has been called a glomus tumour and chaemodectoma or paraganglioma.

Aetiology

• Occur at bifurcation of the common carotid artery
• It can cause the bifurcation to splay
• Tumour can invade base of skull
• It is a rich vascular tumour

Histology

• Chief cells with clear cytoplasm and a round nucleus
• All enclosed in a fibrous tissue framework.

Risk factors

• Commoner in those living at altitude possibly due to hypoxia
• COPD, Cyanotic congenital heart disease
• Familial types exist and cause 7-10%

Rare associations

• Multiple endocrine neoplasia: MEN IIa and MEN IIb
• Tuberous sclerosis complex (TS)
• Neurofibromatosis type 1 (NF1)
• Von Hippel-Lindau disease (vHL)

Clinical

• Pulsatile swelling at medial border of sternomastoid
• Usually presents in middle age
• Tumour can be moved side to side but not up or down
• Swelling mobile laterally and Carotid bruit may be audible
• Typically asymptomatic in most just a lateral neck mass
• They may rarely release catecholamines.

Differentials

• Lymph node
• Glomus vagal tumour
• Anterior triangle masses

Investigations

• CT with contrast and MRI imaging demonstrate the tumour .
• Angiography shows a splaying of the carotid bifurcation (lyre sign).

Management

• Surgical excision may be performed especially in young healthy patients.
• Alternatives are embolization or gamma knife irradiation.
• In elderly patients a more conservative approach may be indicated
• Malignant transformation is encountered in about 10-20%

References

Revisions