Teaching Case

A 9-year-old female patient with no medical history presented with dysphagia and recurrent otitis media. Physical examination and routine laboratory findings were normal.

MRI showed a slightly lobulated mass in the deep masticator space extending posterolaterally to the parotid space and medially to the parapharyngeal space, infiltrating the pterygoid muscles and with mass effect on the torus tubarius and the upper airway. The mass was hyperintense on T2-weighted images and isointense with skeletal muscles on T1-weighted images. Small areas with low signal on T1 and T2-weighted images represented the phleboliths that were confirmed with CT imaging.

Haemangiomas and vascular malformations are both endothelial malformations which were previously classified according to the type of fluid they contained and the size of their channels. Blood-containing lesions were called haemangiomas (capillary, strawberry or cavernous, depending on the channel size) and lymph-containing lesions lymphangiomas or cystic hygromas.

A classification published in 1982 [1] separates endothelial malformations in haemangiomas and vascular malformations according to their histology, natural history and cellular turnover.

Haemangiomas show cellular proliferation, are small or absent at birth and experience rapid growth during infancy and regression during childhood. [2]

Vascular malformations are composed of dysplastic vessels, are always present at birth, grow proportional to child and do not involute. They are subclassified on the basis of their histology as arteriovenous, venous, capillary, lymphatic and mixed. [2]

Although sonography can be used as a primary imaging technique, it is not always useful in cases of deep lesions. MRI imaging is always necessary to characterise the lesion, to delimitate it and to determine the involvement of adjacent structures and whether it is a high- or low-flow malformation.

Venous malformations are slow-flow endothelial malformations composed of ectatic and aberrant venous channels which lead to gradual expansion of the lesion secondary to venous congestion and thrombosis.
Although they can be visible at birth as a dark blue or purple protruding cutaneous mass, they can also present as a deep mass with normal overlying skin. They are known to grow proportionately with the child but can show rapid growth during puberty, pregnancy or after a traumatic injury.
Venous malformations can arise anywhere but are more frequent in the head and neck involving the airway, oral cavity and cervical musculature. [3]

Patients often present with an expansive mass and can refer pain due to venous stasis, small clots or calcified thrombi (phleboliths) and symptoms related to the mass effect.

MRI imaging shows the venous channels as serpentine structures containing slow-flowing blood, hyperintense in T2-weighted images and with intermediate signal in T1-weighted images. [4] Phleboliths appear as round hypointense lesions within those channels [5].
CT is not routinely used, but helps to confirm the presence of phleboliths within the mass, which appear as well-defined calcifications.

Venous malformations can be managed combining different treatment modalities including elastic compression garments for superficial lesions, laser therapy, sclerotherapy and surgical excision [6].

Written informed patient consent for publication has been obtained.