MRI of pathology-proven peripheral nerve amyloidosis

Gavin A. McKenzie, Stephen M. Broski, Benjamin M. Howe, Robert J. Spinner, Kimberly K. Amrami, Angela Dispenzieri, Michael D. Ringler

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

Objective: To highlight the MRI characteristics of pathologically proven amyloidosis involving the peripheral nervous system (PNS) and determine the utility of MRI in directing targeted biopsy for aiding diagnosis. Materials and methods: A retrospective study was performed for patients with pathologically proven PNS amyloidosis who also underwent MRI of the biopsied or excised nerve. MRI signal characteristics, nerve morphology, associated muscular denervation changes, and the presence of multifocal involvement were detailed. Pathology reports were reviewed to determine subtypes of amyloid. Charts were reviewed to gather patient demographics, neurological symptoms and radiologist interpretation. Results: Four men and three women with a mean age of 62 ± 11 years (range 46–76) were identified. All patients had abnormal findings on EMG with mixed sensorimotor neuropathy. All lesions demonstrated diffuse multifocal neural involvement with T1 hypointensity, T2 hyperintensity, and variable enhancement on MRI. One lesion exhibited superimposed T2 hypointensity. Six of seven patients demonstrated associated muscular denervation changes. Conclusion: Peripheral nerve amyloidosis is rare, and the diagnosis is difficult because of insidious symptom onset, mixed sensorimotor neurologic deficits, and the potential for a wide variety of nerves affected. On MRI, peripheral nerve involvement is most commonly characterized by T1 hypointensity, T2 hyperintensity, variable enhancement, maintenance of the fascicular architecture with fusiform enlargement, multifocal involvement and muscular denervation changes. While this appearance mimics other inflammatory neuropathies, MRI can readily detect neural changes and direct-targeted biopsy, thus facilitating early diagnosis and appropriate management.

Original languageEnglish (US)
Pages (from-to)65-73
Number of pages9
JournalSkeletal Radiology
Volume46
Issue number1
DOIs
StatePublished - Jan 1 2017

Keywords

  • Amyloid
  • Amyloidoma
  • Amyloidosis
  • MRI
  • Peripheral nerve

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

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