Bilateral multifocal lower extremity localized soft tissue amyloidomas: case report with ultrasonographic characterization

Amyloidosis may be acquired or hereditary and consists of multiple disease processes characterized by the abnormal deposition of extracellular fibrillary protein aggregates. The presentation of amyloidosis is varied, ranging from an isolated, focal deposition to systemic disease. While systemic involvement is common, a rare entity known as amyloidoma or tumor amyloidosis may also occur. The 75-year-old female in this case presented with slowly growing multifocal bilateral lower extremity masses and was ultimately diagnosed with localized amyloidomas in the absence of chronic illness or systemic disease. This case report includes a description of the sonographic features of localized extremity amyloidoma that, to the best of our knowledge, have not yet been described in the literature. Awareness of the sonographic features, and this unique presentation of multifocal soft tissue extremity amyloidomas will allow for this rare diagnosis to be included in a limited differential diagnosis.