Paraneoplastic necrotizing myopathy in a woman with breast cancer: a case report

Abstract

IntroductionParaneoplastic necrotizing myopathy is a rare disorder, described as a proximal, symmetrical, and rapidly progressing myopathy that is manifested as a paraneoplastic syndrome. Diagnosis is established via histological examination of the muscle biopsy.Case presentationWe present the case of a 53-year-old woman, born in Guinea-Bissau, with a history of locally advanced breast cancer, diagnosed ten months previously. The patient had experienced a progressively proximal muscle weakness of the lower extremities, which led to a total inability to walk. Upon neurological examination, the patient showed muscle weakness and atrophy in both proximal lower extremities without myalgia. Muscle strength was graded according to the Medical Research Council Scale as 2 out of 5 in the bilateral iliopsoas muscle, and 4 out of 5 in the bilateral quadriceps femoris. The deep-tendon reflexes were hypoactive. The laboratory examination showed increased values of serum creatinine kinase and myoglobin. An electromyogram showed an incomplete interference pattern during voluntary contraction in the iliopsoas and quadriceps femoris. The motor nerve conduction was 44.1 m/s and 44.3 m/s in the right and left tibial nerves, respectively, and 46.5 m/s and 46.1 m/s in the right and left peroneal nerves, respectively. The sensory motor nerve conductions and the compound motor action potential amplitudes were normal. These findings, despite not being specific, suggested a myopathy. Consequently, a muscle biopsy was performed. A biopsy specimen showed myopathic changes that were characteristic of a necrotizing myopathy.ConclusionTreatment for this syndrome consists of controlling the tumor, and providing corticoid therapy. This led to the partial remission of the neurological manifestations.

A rare case of breast carcinoma presenting with paraneoplastic cerebellar degeneration

“…(5) These patients present with rapidly progressive cerebellar dysfunction. Subtle cognitive and motor impairment may also be involved.…”

Review: Immune‐mediated necrotizing myopathies – a heterogeneous group of diseases with specific myopathological features

“…First, the typical clinical picture of DM with specific involvement of the skin (if present) will help to differentiate, also the presence of specific DM-associated autoantibodies, which may be useful to evaluate a decreased (anti-Mi-2) [64,65] or an increased (anti-p155/ 140) [66,67] risk of developing cancer. The descriptions of paraneoplastic necrotizing myopathy cases in the literature are quite sparse [11,12,14,15,25,26,29,[68][69][70][71].…”

Paraneoplastic necrotizing myopathy associated with adenocarcinoma of the lung – a rare entity with atypical onset: a case report

“…Our patient was not tested for anti-SRP autoantibodies because testing was not available. Polyneuropathy may also occur in paraneoplastic NAM [14,15], in some cases associated with previous antiblastic treatment [8]. It is probable that our patient had a mild pre-existing sensory-motor axonal polyneuropathy, as mild fiber type grouping consistent with reinnervation was observed.…”