Abstract
Introduction Imatinib is a tyrosine kinase inhibitor (TKI) widely used in the treatment of chronic myeloid leukaemia and other malignancies in which tyrosine kinases are over expressed. The first case of neuropathy associated with imatinib was reported in 2011.1 A distal mixed axonal neuropathy is now recognised as an uncommon late adverse effect of imatinib,2 however other types of neuropathy have not been described previously. We report a case in which both a mixed axonal neuropathy and an acute, relapsing, steroid responsive neuroplexopathy occurred.
Case description A 73-year-old man with CML and JAK2 positive myeloproliferative neoplasm was treated with imatinib and pegylated interferon. In 2020 he developed an acute neuropathy affecting the left leg. MRI showed abnormal signal and enhancement in the sciatic trunk and related nerves. There was no improvement following withdrawal of interferon but rapid improvement following methylprednisolone. A mild distal mixed axonal neuropathy was present at that time. In October 2022 he developed an acute common peroneal neuropathy in the other leg and nerve conduction studies showed marked worsening of the generalised axonal neuropathy. As no other cause was found imatinib was ceased. Marked symptomatic improvement occurred within 6 weeks.
Discussion This is the first report of a relapsing steroid responsive neuroplexopathy associated with TKI therapy. It suggests that TKIs may rarely be associated with an inflammatory neuropathy, as well as with a generalised mixed axonal neuropathy. As TKIs are widely used in haematological and other malignancies, awareness of this treatable complication is important.
References
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