Question of the Week
For October 21, 2014
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Brainstem tumorMyasthenia gravisMicroscopic polyangiitisCarotid artery dissectionLung cancer
Key Learning Point View Case Presentation
The gradual development of arm weakness and Horner syndrome in an older former smoker is most indicative of a diagnosis of an apical bronchogenic cancer known as a Pancoast tumor.
Pancoast syndrome is caused by superior sulcus tumors compressing against nerve structures as they pass through or near the thoracic inlet. Compression of the C8, T1, and T2 nerve roots can cause pain and neurologic compromise of those nerves. In addition, interruption of the sympathetic nerve chain running to the head can result in Horner syndrome, which is characterized by unilateral miosis, ptosis, and anhidrosis. Treatment of Pancoast tumors involves multidisciplinary care coordinated among a thoracic surgeon, a radiation oncologist, and a medical oncologist.
Although myasthenia gravis can cause ptosis and muscle weakness, it is not associated with miosis (a component of Horner syndrome).
Microscopic polyangiitis leads to renal insufficiency and can cause sensorimotor neuropathy but is not associated with the development of Horner syndrome.
Although carotid artery dissection could progress to stroke and subsequently cause arm weakness, this event would likely occur more acutely than the gradual development of Horner syndrome.
Arm weakness and numbness in the fingers is more consistent with a dermatomal distribution than with a brainstem lesion.
Last reviewed Nov 2016. Last modified Apr 2014.
Vallières E et al. Pancoast tumors. Curr Probl Surg 2001 May 3; 38:293. > View Abstract