Age / Sex : 52 / M

Neuroma of amputated stump

Discussion

Findings: A
bilobulated well defined hypoechoic mass was seen on ultrasonography, which
connects with tibial nerve at popliteal fossa. Another oval mass was originated
from commom peroenl nerve. CT scan show fusiform enlargement of tibial and
common peroneal nerve at distal thigh level of amputated stump.  

Differential Diagnosis:

Diagnosis:
Neuroma of amputated stump

Discussion:

The causes
of stump pain in lower limb amputation are aggressive bone edge, heterotopic
ossification, osteomyelitis, cancer, tumor recurrence, neuroma, phantom pain,
bursitis, stress fracture, and cutaneous lesions.

Neuroma is a
non-neoplastic proliferation that occurs at the end of an injured nerve. Pain
associated neuroma does not always have a precise topography. Imaging is useful
for confirmation and localization of painful neuroma. On US, neuromas appear as
a hypoechoic mass with irregular or poorly defined margins. Neuroma has low
density on CT images in the course of nerve. It has low signal intensity on
T1-weighted images, and intermediate to high signal intensity on T2-weighted
images and demonstrates variable enhancement. Surgical clips or metallic
fragments can cause artifact. Conservative therapy has been reported. 

Conservative
therapy with corticosteroid, nerve stimulation, or reshaping of the socket may
help relieve pain. Resection of a neuroma should not be undertaken because it
can induce extension of the scar area with the potential of generating a new
symptomatic neuroma.

References:

1.    
Henrot P.,
Stines J., Walter F., et al. Imaging of the painful lower limb stump. Radiographics
2000;20:S219-S235.