We're unable to sign you in at this time. Please try again in a few minutes.
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Images in Neurology |

Schwannoma of the Palmar Cutaneous Nerve Electrodiagnosis With Radiologic and Pathologic Correlations

Anastasia Zekeridou, MD; Francois Ochsner, MD; Friedrich Medlin, MD; Johannes A. Lobrinus, MD; Fabio Becce, MD; Thierry Kuntzer, MD
Arch Neurol. 2012;69(11):1512. doi:10.1001/archneurol.2012.168.
Text Size: A A A
Published online


A 61-year-old otherwise healthy man presented with pain and altered sensation in his right wrist and palm. Physical examination revealed painful and lightening Tinel sign at the base of the thenar eminence as the only abnormal sign. Electrodiagnostic studies showed a 30% reduction in the sensory action potential amplitude of the palmar cutaneous nerve as compared with the left, without any change in the usual transcarpal parameters of the median and ulnar nerve conduction studies. Magnetic resonance imaging of the wrist demonstrated a subcutaneous mass on the palmar aspect of the wrist, suggestive of a peripheral nerve sheath tumor1 (Figure 1). At surgery, the tumor was found to be an encapsulated mass of the thenar branch of the median nerve, in contrast with the invasive, nonencapsulated characteristics encountered in neurofibromatomas.2 Histopathologic examination was compatible with a schwannoma (Figure 2). The operation was reported to be without complications, and at 12 months' follow-up, the patient was asymptomatic, underlying the good prognosis of some median nerve tumors.3

Figures in this Article

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

First Page Preview

View Large
First page PDF preview


Place holder to copy figure label and caption
Graphic Jump Location

Figure 1. Magnetic resonance imaging findings. Axial T1-weighted (A), proton density–weighted (B), and gadolinium-enhanced fat-suppressed T1-weighted magnetic resonance images (C), revealing a tumor in the cutaneous branch (arrow) of the median nerve (arrowhead), medial to the flexor carpi radialis tendon (*), avidly enhancing after intravenous administration of contrast material. C indicates capitatum; L, lunatum; R, radius; and U, ulna.

Place holder to copy figure label and caption
Graphic Jump Location

Figure 2. Pathology findings. Histological overview of the tumor, showing a well-delineated nodular encapsulated mass with histologic section showing the typical biphasic pattern of benign schwannoma, with an Antoni A (*) and B (†) pattern (hematoxylin-eosin).




Also Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
Please click the checkbox indicating that you have read the full article in order to submit your answers.
Your answers have been saved for later.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.


Some tools below are only available to our subscribers or users with an online account.

0 Citations

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Related Content

Customize your page view by dragging & repositioning the boxes below.

Articles Related By Topic
Related Collections

The Rational Clinical Examination: Evidence-Based Clinical Diagnosis
Evidence to Support the Update

The Rational Clinical Examination: Evidence-Based Clinical Diagnosis
Reference Standard Tests