Age / Sex : 80 / F

Chief complaint : Palpable mass, medial aspect of right proximal thigh

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Courtesy : Eunsun Oh, Soonchunhyang University Seoul Hospital

Cavernous hemangioma

Discussion

Findings: 

 About 7.3 x 6.8 x 7.0 cm sized well-defined T1 heterogenous high signal intensity and T2 heterogenous low signal intensity mass with peripherally internal globular enhancment, medial aspect of right proximal thigh, probably intramuscular layer of adductor muscles.

Differential Diagnosis:

 Organizing hematoma, neurofibroma, lipoma, soft-tissue sarcoma

Pathology

The specimen consists of a gray white soft tissue, clinically from right thigh mass, weighing 178gm and measuring 8x7x6.5cm. On section, it shows a hemorrhage.

Consistent with cavernous hemangioma.

Discussion:

 Soft-tissue hemangiomas are common neoplasm of benign histologic origin. They are the most common of the angiomatous lesions and represent up to 7% of all benign soft-tissue tumors in the general population. Histologically, soft-tissue hemangiomas are subdivided into five categories, depending on the predominant type of vascular channel identified. These subdivisions include capillary, cavernous, arteriovenous, venous, and mixed variations.

  Cavernous hemangiomas are larger and deeper and occur later in life. As in our patient, they are often intramuscular. 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.

 Radiographs of soft-tissue hemangiomas are usually normal, phleboliths are associated with cavernous hemangiomas in approximately 50% of cases. A nonspecific soft-tissue mass may also be noted. If the mass is large enough and in close proximity to adjacent bone, osseous changes including periosteal reaction and cortical thickening can occur. In some cases, pressure erosion from the adjacent mass can result in a pathologic fracture.

 At nonenhanced CT, an ill-defined mass of similar attenuation to muscle may be identified. Phleboliths too small to identify on radiographs can be revealed. After administration of contrast material, significant enhancement is typical.

 US can demonstrate a complex mass. If phleboliths are abundant, acoustic shadowing may also be documented. Doppler evaluation may show low-resistance arterial flow with forward flow during both systole and diastole.

 Currently, the standard for imaging evaluation of soft-tissue hemangiomas is MR imaging. Typically, all sequences show a heterogeneous mass (although lesions measuring under 2 cmtend to be homogeneous), reflecting the mix of tissues present. T1-weighted images best 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. As on contrast-enhanced CT images, the serpentine nature of the hemangioma may be depicted. If blood flow through these vascular channels is rapid enough, the signal may remain low in intensity with all MR imaging sequences. If gadolinium contrast material is administered, prominent enhancement of the angiomatous tumor is expected.

References:

Olsen KI, Stacy GS, Montag A: Soft-tissue cavernous hemangioma. Radiographics : a review publication of the Radiological Society of North America, Inc 2004, 24(3):849-854.