Peripheral primitive neuroectodermal tumour in a dog

Features of a rare peripheral primitive neuroectodermal tumour arising from the thoracic spine in a juvenile canine patient

Peripheral primitive neuroectodermal tumours are rare tumours in juveniles. The current patient was a paraplegic 8‐month‐old Scottish deerhound with a suspected pulmonary mass. Radiographically, there was a large extrapleural mass within the mid‐left hemithorax. On MRI, the mass was mainly hyperintense on T2‐weighted images, isointense on T1‐weighted images and was heterogeneously strongly contrast enhancing with a multilobulated appearance, spinal cord compression, paraspinal musculature invasion and intrathoracic extension. Those changes were confirmed on post‐mortem, and the mass diagnosed based on immunohistochemistry.

Retroperitoneal extraosseous peripheral primitive neuroectodermal tumor in a Formosan serow: case report and literature review

A 10-y-old female captive Formosan serow (Capricornis swinhoei) was inactive and was azotemic. An autopsy was performed following her death, and multiple irregularly shaped, white-to-gray masses of 0.5-2 cm diameter were noted on both ureters, the left adrenal gland, urinary bladder, and uterus. Microscopically, organs were effaced by a poorly demarcated, highly infiltrative neoplasm, composed of neoplastic round cells arranged in islands, sheets, or nests with occasional rosette formation. The neoplastic cells were small: ≤2 red blood cell (≤ 15 μm) diameter. The neoplastic cells were positive for CD56, CK, FLI-1, and NSE, but negative for desmin, GFAP, melan A, NF, PAX-8, S100, synaptophysin, and vimentin. Therefore, the diagnosis of retroperitoneal extraosseous peripheral primitive neuroectodermal tumor (pPNET) was made. pPNET with FLI-1 expression has not been reported previously in animals, to our knowledge.

Post-traumatic Intraocular Leiomyosarcoma in a Domestic Bovine Calf (Bos primigenius taurus)

The present report describes a case of a post-traumatic ocular leiomyosarcoma in a calf (Bos primigenius taurus) including clinical, histopathological and immunohistochemical features. Following a traumatic episode, the animal developed opacification of the lens and shrinkage of the eye. Subsequently, the ocular lesion increased in size over a period of 6 weeks and reached up to 16 cm in diameter with infiltration into the cranium. At necropsy examination, the kidneys, liver and spleen exhibited multiple firm white metastases up to 2 cm in diameter. The mass was composed of closely-packed streams and bundles of neoplastic cells, which immunohistochemically expressed vimentin and alpha smooth muscle actin. Based on the anamnestic data, morphological appearance, distribution and immunohistochemical results, a diagnosis of a post-traumatic intraocular leiomyosarcoma was made. The tumour may have originated from cells lining the pectinate ligament of the ciliary body.

Case of a miniature dachshund with a primitive neuroectodermal tumor confined to the forebrain region treated with a combination of surgery and chemotherapy

A miniature dachshund aged 9 years and 7 months with a history of polyuria/polydipsia and depression was referred. General physical and neurological examinations revealed no obvious abnormalities. MRI of the brain revealed a large space-occupying lesion in the left frontal lobe. This was surgically removed and pathologically diagnosed as a primitive neuroectodermal tumor (PNET). Although the clinical signs had been improved, follow-up MRI revealed recurrence of the tumor. Lomustine was administered, but 1 year after surgery, the dog exhibited cluster seizures and died. This is the first reported case of a dog with PNET confined to the forebrain region treated by surgical resection in combination with chemotherapy, as observed by repeated follow-up MRI.