APRIL 2008

Dog, Subcutis: Liposarcoma

Liposarcomas are rare malignant tumors of white adipose cell lipoblasts. They are considered a soft tissue neoplasm because of their mesenchymal or connective tissue cell origin. They often arise from the skin and subcutis. Most reports indicate that liposarcomas are unlikely to metastasize; however, a few published reports suggest that liposarcomas are aggressive, locally invasive, and commonly metastasize to the lungs, liver, and bone. The locally aggressive nature of this neoplasm requires aggressive surgical resection, which often results in long-term remission or cure. The identification and evaluation of resection margins is of utmost importance in appropriate case management.

MAY 2008

Dog, Eye: Corneal Perforation with Iris Prolapse

Iris prolapse can occur when the cornea is perforated due to any cause. It is a common sequel to penetrating corneal wounds and/or ruptured corneal ulcers. Common cuases in the dog include perforation by a cats claw, melting corneal ulcers leading to a desmetocoele and then subsequent rupture or in hunting or active dogs by foreign body penetration. With corneal perforation, the aqueous humor rapidly escapes, and a relative vacuum is created in front of the iris, thus leading to iris prolapse.

JUNE 2008

Dog, Mandible: Telangiectatic osteosarcoma

Histologically, osteosarcomas consist of malignant mesenchymal cells that are round, to stellate to spindeloid and produce an osteoid matrix. This osteoid matrix is a distinguishing feature of OSAs. Subclasses of osteosarcomas are determined based on the characterization of the cells as well as the type and amount of matrix present. Subclasses include osteoblastic, chondroblastic, fibroblastic, poorly differentiated, Giant-cell type and telangiectatic osteosarcomas. Telangiectatic osteosarcomas are agressive tumours that destroy pre-existing bone and form blood-filled cavities lined by tumour cells rather than endothelium. There is no apparent evidence of different biological behavior between the subclasses. Recently Grading has been attempted but statistically no correlation was found. The data indicated Grade III tumours were more likely to metastasise that grade I or II tumours.