65 years old male on hemodialysis with axillary and inguinal swelling

Case provided by Nora

History
65 years old male on hemodialysis with swelling in the axillary and inguinal region and malfunction of the arteriovenous dialysis fistula. The patient had a medical history of chronic renal failure with hemodialysis treatment for the past 35 years.

Imaging findings
The contrast-enhanced CT (A, B, and C) shows bilateral juxtaarticular inhomogeneous tissue masses (stars in B and C) and signs of destructive bone lesions (arrow heads in A) involving the hips and the shoulders. The destructive bone lesions are characterized by subchondral cystic lesions with well-defined sclerotic margins. No evidence of pathologic fractures.

Diagnosis
Hemodialysis-related amyloid arthropathy

Discussion
This is a distinct example of a hemodialysis-related amyloid arthropathy, which occurs secondarily to the deposition mainly of β2--microglobulin particularly in bone, cartilage, muscle and tendons. Due to renal impairment, the levels of the normally present and renally catabolised molecule of the HLA-family class I can rise up to 60-fold and accumulate in the body. Conventional hemodialysis membranes are impermeable to β2--microglobulin. Growing evidence suggests that heemodialysis itself can play a role in increasing the synthesis of β2—Microglobulin, but as hemodialysis-related amyloidosis can also be found in patients with peritoneal dialysis and in renal impairment without dialysis, the role of this mechanism remains uncertain.

The incidence of hemodialysis-related amyloidosis is not known. However, post-mortem histologic evidence of joint biopsies suggests that it can be seen in as much as 20% of patients after just 2–4 years of hemodialysis and in 100% of patients with a history of 13 years or more of hemodialysis.

The first diagnosis of hemodialysis-related amyloidosis is often made at CT performed to evaluate vague joint pain or pathologic fractures. Visceral depositions can be also present with signs of cardiac impairment or, for example, bowel obstruction or difficulty of swallowing. The deposits in the musculoskeletal system often present as carpal tunnel syndrome or flexion contractures of the fingers. Another common clinical manifestation is (cervical) spondyloarthropathy and bilateral shoulder pain. At MRI, amyloid depositions have low to intermediate signal intensity in both T1 weighting and T2 weighting.

Despite from amyloid arthropathy, skeletal complications in renal impairment include also renal osteodystrophy and secondary hyperparathyroidism-related pathologies such as brown tumours, bone resorption and sclerosis (with distinctive patterns such as for example rugger-jersey spine). The imaging findings of amyloid arthropathy were discussed earlier. In cases not as marked as the abovementioned the differentiation between metastatic disease and of course multiple myeloma and bone involvement of secondary amyloidosis is essential.

Osseous signs of (secondary) hyperparathyroidism include generalised bone loss with mainly subperiosteal bone resorption areas with occasional cystic lesions mainly in the long bones and in the maxillofacial region. Sites of extreme osteoclast activity may cause tumor-mimicking cystic lesions with thinning of the cortex and well-defined margins known as brown tumours. There is no juxtaarticular predilection, and unlike amyloidomas, brown tumours tend to have a preserved bone cortex.

Teaching points

  • Hemodialysis-related amyloid arthropathy generally occurs in patients with long-term hemodialysis
  • Hemodialysis-related amyloid arthropathy preferentially develops in large joints and presents with juxtaarticular soft tissue masses and subchondral cystic bone lesion
  • Think of amyloid arthropathy when reporting examinations of patients under or after chronic haemodialysis treatment even if they do not have symptoms

 

Recommended reading

Kiss at al.
Dialysis-Related Amyloidosis Revisited.
American Journal of Roentgenology 2005 185:6, 1460-146

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