Rapidly progressive subacute motor neuronopathy disclosing type B2 thymoma

Neuronopatia motora subaguda rapidamente progressiva associada com timoma tipo B2

A 73-year-old man presented with a three-month history of muscle wasting, cramps and marked weight loss. Examination revealed severe global amyotrophy (Figure), fasciculations, reduced deep tendon reflexes and flaccid quadriparesis. Nerve conduction studies were unremarkable. Needle electromyography showed acute and chronic partial denervation in the cervical, thoracic and lumbosacral segments. A full-body CT scan disclosed a large mass in the anterior mediastinum, which showed a type B2 thymoma.

Figure
Findings in subacute motor neuronopathy. Severe muscle wasting in proximal (A) and distal muscle groups (B; black arrow). (C) Rarefaction of interference patterns in submaximal voluntary contraction, and fibrillation and positive sharp wave at rest. (D) Chest CT scan showed a large mass in the anterior mediastinum (white arrow).

Paraneoplastic neuropathies represent an expanding group of immune-mediated neuropathies associated with a known or unidentified neoplasm¹. Pure motor neuropathy is represented by subacute motor neuronopathy¹, commonly associated with Hodgkin’s and non-Hodgkin’s lymphoma^1,2 and, rarely, with thymoma².

References

• ¹
  Graus F, Dalmau J. Paraneoplastic neuropathies. Curr Opin Neurol. 2013;26(5):489-95. https://doi.org/10.1097/WCO.0b013e328364c020
  » https://doi.org/10.1097/WCO.0b013e328364c020
• ²
  Stoll DB, Lublin F, Brodovsky H, Laucius JF, Patchefsky A, Cooper H. Association of subacute motor neuronopathy with thymoma. Cancer. 1984;54(4):770-2. https://doi.org/10.1002/1097-0142(1984)54:4<770::AID-CNCR2820540430>3.0.CO;2-E
  » https://doi.org/10.1002/1097-0142(1984)54:4<770::AID-CNCR2820540430>3.0.CO;2-E

Publication Dates

• Publication in this collection
  Jan 2018

History

• Received
  22 Feb 2017
• Accepted
  11 Sept 2017