A peripheral nerve sheath tumour in the median nerve of a dog

Abstract

A 6‐year‐old, female, spayed, flat‐coated retriever cross presented with a 4‐month history of progressive left thoracic limb lameness that was unresponsive to medical treatment. Initial advanced imaging with computed tomography did not identify a cause, and the dog was discharged on rest and analgesia. The dog re‐presented three weeks later with worsening lameness, discomfort and a painful, palpable mass on the medial aspect of the left thoracic limb just proximal to the elbow. Further investigations included electrodiagnostics and ultrasonography, which identified a lesion of the median nerve. A surgical biopsy was taken and histopathology diagnosed a peripheral nerve sheath tumour. The dog underwent surgery for thoracic limb amputation and nerve resection, with complete margins achieved. The dog went on to recover well with no signs of relapse 39 months later. This report describes the findings and treatment of a peripheral nerve sheath tumour in the thoracic limb of a dog.

Relationship between magnetic resonance imaging findings and histological grade in spinal peripheral nerve sheath tumors in dogs

“…On the contrary, other soft tissue tumors only rarely are accompanied by muscle atrophy and compression or constriction of the peripheral or central nervous system is required to induce such changes. Chronic denervation of the target organ from motor nerve fiber loss adds to disuse of the affected limb, ultimately resulting in muscle atrophy 18 . For some body areas and skeletal muscles, such as those innervated by the brachial plexus, volumetric changes can be subtle and may require measurements and comparison with the normal, clinically unaffected, side to become evident.…”

“…Chronic denervation of the target organ from motor nerve fiber loss adds to disuse of the affected limb, ultimately resulting in muscle atrophy. 18 For some body areas and skeletal muscles, such as those innervated by the brachial plexus, volumetric changes can be subtle and may require measurements and comparison with the normal, clinically unaffected, side to become evident. For this reason, and concordance with previous literature, 15 we recommend increasing the size of the field of view (FOV) by starting the MRI examination with the dorsal plane in order to visualize a large portion of axial and upper appendicular skeletal muscles for side comparison.…”

“…14,15 Despite accurate spatial resolution, imaging techniques cannot definitively support a clinical diagnosis of PNST. [14][15][16][17][18] Differential diagnoses include other tumors, such as meningioma in the intradural compartment, 19 lymphoma and sarcomas, or inflammatory lesions such as focal hypertrophic neuritis 20,21 and chronic hypertrophic ganglioneuritis, 22 all presenting with comparable imaging findings.…”