Case Report : Soft Tissue Cavernous Hemangioma

13 y old boy with left thigh swelling, Large well defined irregular non encapsulated complex altered signal SOL in left mid thigh anterolateral aspect predominantly in intermuscular fat plane between rectus femoris & vastus lateralis , intermedius with intramuscular components  with marked T2 hyperintese signal, T1 hypointense with hyperintense foci showing blooming with unremarkable femoral vessels  and without any feeding artery or draining vein with normal femur – likely suggesting slow flow vascular malformation like cavernous hemangioma.

Discussion by Dr MGK Murthy, Dr GA Prasad

Soft-tissue hemangiomas are common neoplasms of benign histologic origin & are the most common of the angiomatous lesions. Cavernous hemangiomas are composed of dilated, blood-filled spaces lined by flattened endothelium. Calcification is common. They do not spontaneously involute and therefore may require surgical intervention.

X ray -  usually normal,  may show  pheboliths  or soft tissue opacity.

NECT-  an ill-defined mass of similar attenuation to muscle may be identified,  Phleboliths can be well seen.

Currently, the standard for imaging for soft-tissue hemangiomas is MR imaging. All sequences show a heterogeneous mass ( lesions measuring under 2 cm tend to be homogeneous), reflecting the mix of tissues present. T1-weighted images reveal areas of high-signal-intensity adipose tissue, most prominent along the circumference of the vascular complex. This fatty tissue may reflect muscle atrophy secondary to chronic vascular insufficiency caused by the steal phenomenon. In some patients, the fat overgrowth is so prominent that these lesions are mistaken for lipomas. The central angiomatous core of the neoplasm shows high signal intensity on T2-weighted images. If blood flow through the vascular channels is rapid enough, flow voids may be seen.  After gadolinium contrast material -  prominent enhancement of the angiomatous tumor is seen.

Differentials  in non contrast MR – lymphangioma / soft  tissue neoplasms.

Biopsy attempts in cavernous tumors primarily yield blood products and are unlikely to provide sufficient solid tissue for histologic analysis. Furthermore, biopsy of soft-tissue hemangiomas may lead to bleeding complications, particularly if the tumor is intramuscular. Given that imaging is often diagnostic for soft-tissue hemangiomas, biopsy can generally be avoided.