A Case of Atypical Amyloid Polyneuropathy with Predominant Upper-limb Involvement with the Diagnosis Unexpectedly Found at Lung Operation

Abstract

We present a patient of familial amyloid polyneuropathy (FAP) with predominant upper-limb involvement, the pattern of which resembled a mononeuropathy multiplex pattern. Sural nerve biopsy failed to diagnose the disorder, but lung partial resection performed later for other diagnostic purposes suggested FAP. A rare mutation in the transthyretin gene (S50R) was subsequently confirmed. Diagnostic challenges of FAP with atypical clinical presentations, including difficulties in pathological diagnosis, are discussed with a review of the literature.

Effect on disability and safety of Tafamidis in late onset of Met30 transthyretin familial amyloid polyneuropathy

“…During the first 6 months of treatment, the rate of NIS‐LL progression was unchanged compared with the pre‐treatment period; 55% of patients showed an increase in NIS‐LL of > 2 points and 31% an increase of 3.2 points compared with the pre‐treatment score. The upper limb involvement study was helpful because the NIS‐UL score is often abnormal, especially in patients with a multifocal upper limb pattern . At 1 year, all but two of the treated patients increased either their NIS‐LL or the NIS‐UL score.…”

Upper limb onset of hereditary transthyretin amyloidosis is common in non‐endemic areas

“…Almost two decades later, Dwulet and Benson reported it was due to a Ser84Ile mutation in the TTR gene . Since then, there have been only a few reports of familial amyloid polyneuropathy (FAP) with ULO . hATTR is a disabling and life‐threatening disease but therapies that can greatly modify the natural history have emerged .…”

FAP is a Candidate Disease in Patients with Undetermined Polyneuropathy

“…Some of the patients had been misdiagnosed as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). As in the case presented by Shirota et al (5), FAP is sometimes difficult to diagnose or it is misdiagnosed as another neuropathic disorder.…”

“…Shirota et al presented a 57-year-old Japanese FAP patient with predominant upper-limb involvement, the pattern of which resembled a mononeuropathy multiplex pattern (5). Pathological examinations for sural nerve biopsy failed to diagnose the disorder, but that for lung partial resection performed later for other diagnostic purposes suggested FAP.…”