Amputation Stump Neuroma

Amputation stump neuromas are a common cause of stump pain and can be classified as terminal or spindle neuromas. Terminal neuromas are formed as distal axons in a transected nerve grow in an attempt to reunite with non-existent distal axons cells and form a bulbous mass. Spindle neuromas, on the other hand, are not located at the transected nerve, but at a peripheral nerve that has been exposed to microtrauma from stretching or compression by local scar tissue.

Amputation stump neuromas usually present within a year of surgery and can continue to enlarge for 3 years.

MRI is the imaging modality of choice for detection of a neuroma and differentiation of soft tissue stump mass from tumor recurrence. Stump neuromas have low signal intensity on T1-weighted images and intermediate-to-high signal intensity on T2-weighted images. They demonstrate variable contrast enhancement. Ultrasound can also be used for diagnosis of neuromas, which classically appear as oval-shaped, hypoechoic masses that are contiguous with a nerve. The margins of the mass can be well-defined or irregular.

References

• Ernberg LA, Adler RS, Lane J. Ultrasound in the detection and treatment of a painful stump neuroma. Skeletal Radiol. 2003 May;32(5):306-9.
• Henrot P, Stines J, Walter F, Martinet N, Paysant J, Blum A. Imaging of the painful lower limb stump. Radiographics. 2000 Oct;20 Spec No:S219-35.