RETRACTED ARTICLE: Ulnar malignant peripheral nerve sheath tumour diagnosis in a mixed-breed dog as a model to study human: histologic, immunohistochemical, and clinicopathologic study

Abstract

Canine Malignant Peripheral Nerve Sheath Tumors (MPNSTs) are uncommonly reported in the ulnar, since they are underestimated relative to the more common spindle cell tumours of soft tissue. In dogs, MPNST accounts for 27% of nervous system tumours. In man, MPNST represents 5-10% of all soft tissue sarcomas and is often associated with neurofibromatosis type 1 (NF-1).An 8-year-old, 9 kg, female mixed-breed dog with a subcutaneous mass on the upper right side of the ulnar region was presented to the small animal research and teaching hospital of Tehran University. The dog was anorexic with general weakness. The mass (7 × 4 cm) was removed surgically and processed routinely. Microscopically, the mass was composed of highly cellular areas with a homogeneous population of round or spindle cells, high cellular pleomorphism, high mitotic index and various morphologic patterns. Furthermore, spindle cells arranged in densely or loosely sweeping fascicles, interlacing whorls, or storiform patterns together with wavy cytoplasm, nuclear palisades, and round cells were arranged in sheets or cords with a meshwork of intratumoral nerve fibers. In addition, in this case the presence of neoplastic cells within the blood vessels was observed. Immunohistochemically, tumor was positive for vimentin and S-100 protein. The histopathologic features coupled with the S-100 and vimentin immunoreactivity led to a diagnosis of malignant neurofibroma.To the best of our knowledge, primary ulnar MPNST has not been reported in animals. This is the first documentation of an ulnar malignant peripheral nerve sheath tumour in a dog.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1310907815984587

Molecular Heterogeneity of Canine Cutaneous Peripheral Nerve Sheath Tumors: A Drawback in the Diagnosis Refinement

“…Additionally, benign forms showed a weaker labeling when compared to the malignant ones. Our results are in agreement with other investigations in which S-100 immunoexpression was considered a feature of canine and feline MPNSTs (24,27,29). Malignant transformation of benign peripheral nerve sheath tumors has been described in humans (33).…”

“…The association between S-100 immunoexpression and the biological behavior of PNST is controversial and still being debated by several authors (11,24,27,29,31,32). In the present study, we observed S-100 positivity in 55% of all tumors.…”

“…Also, in our study, all cases showed a consistently expression of vimentin. Previous investigations reported that, in veterinary medicine, vimentin is an immunohistochemistry marker invariably positive in all PNSTs regardless its biological behavior (5,11,13,16,19,(20)(21)(22)(23)(24)(25)(26)(27)(28)(29). Interestingly, in our study, differences in the labeling intensity were observed between the benign and the malignant cases that beared on the decreased of the vimentin score values within the latter group.…”

Frameless stereotactic volumetric modulated arc radiotherapy of brachial plexus tumours in dogs: 10 cases

“…1,2 Canine PNSTs resemble malignant PNSTs in humans, regarding both histology and behaviour. 3,4 In detail, PNSTs of the tract C6-T2 can be classified as "peripheral" if involving nerves distal to the brachial plexus, as "of the plexus" if involving the brachial plexus itself and the emerging nerves from C5 to T2 distal to the intervertebral foramina and as "of the roots" if involving the dorsal or ventral roots within the spinal canal; tumours involving more than one location are classified according to their most proximal location. 5 This kind of tumour spreads both proximally and distally along the nerve and may ultimately involve the spinal cord, causing compression and associated neurological deficits.…”

“…At present, surgery is considered the treatment of choice. 4,[8][9][10][11][12] However, the overall prognosis for surgical management of canine PNSTs involving the brachial plexus or its roots is deemed unsatisfactory, with a median survival time of 12 months in dogs affected by plexus tumours and of 5 months for root tumours. 5 Tumour recurrence occurs in 78% of cases, with a relapse-free interval of 7.5 months for surgically treated dogs for plexus tumours and of 1 month for plexus and root tumours.…”