Diffuse venous malformations of the upper limb: morphologic characterization by MRI and venography

Abstract

Objectives. To define the morphologic abnormalities in patients presenting with diffuse pure venous malformations (VM) of the upper extremity. Subjects and methods. A retrospective review of MRI and venography was performed on five patients, aged 6 months to 20 years, with extensive VM of the upper limbs. Abnormalities of major conducting veins were categorized as varicosities, stenoses, and asymmetrical pouches; anomalous venous spaces were classified into confluent lakes, interconnecting channels and spongelike plexiform networks. MRI and venographic data were reviewed separately and then simultaneously in order to establish correlation between types, location, and extent of lesions. Results. In all patients, the percentage of replacement of normal tissues by VM was shown by MRI to be significantly higher in the distal limb than in the proximal limb. Involvement of multiple tissue layers was seen in all cases, including, with a decreasing rate, muscles, tendons, interosseous membrane of the forearm, and bone. Venography showed superficial varicosities, frequently associated with stenoses and assymetric pouches in all patients. Interconnecting channels and venous lakes were noted in half of the segments, typically in muscle and other deep locations, and subcutaneous spongelike lesions were seen in two patients. MRI provided a more accurate evaluation of tissue extent. Venograms better demonstrated morphological details and provided more information about the venous drainage. Direct comparison of MR images with venograms helped to identify and characterize venous lesions on cross-sectional MR data. Conclusion. Diffuse VM of the upper extremity are most extensive distally, and all tissues layers can be involved, each with a characteristic morphologic appearance. The morphology of different components of the VM is related to the nature of the surrounding tissue.