Intermandibular malignant mesenchymoma in a crossbreed dog

Abstract

A 12-year-old German shepherd crossbreed dog was presented with a submandibular mass that was initially diagnosed as myxosarcoma on incisional biopsy. Chest radiographs were taken for staging, and magnetic resonance imaging was performed to assess the feasibility of cytoreductive surgery before adjuvant radiotherapy. The dog underwent debulking surgery, and histology permitted reclassification of the tumour as a malignant mesenchymoma (with myxosarcomatous and osteosarcomatous differentiation). The dog was subsequently treated with four fractions of radiotherapy given at seven-day intervals and three doses of carboplatin. The dog remained stable following therapy until its condition acutely deteriorated, and it was euthanased 153 days after surgery. On postmortem examination, there were no signs of local tumour recurrence, but metastases were observed both in the thorax and in the abdomen.

An Intra-Abdominal Malignant Mesenchymoma Associated with Nonabsorbable Sutures in a Ferret (Mustela Putorius Furo)

“…6 In dogs, malignant mesenchymoma has been reported in the abdominal cavity, 22 heart, 13 liver, 14 thigh, 17 and mandible. 18 The 2 major differential diagnoses for the neoplasm in the ferret of the current report were an extraskeletal compound osteosarcoma and a poorly differentiated soft tissue sarcoma with osseous metaplasia. The diagnostic criteria for extraskeletal osteosarcoma usually include the production of bone, presence of osteoid and possibly chondroid matrix, and a neoplasm that is located in soft tissue without any attachment to the skeleton.…”

“…Malignant mesenchymoma is considered to be a mesenchymal neoplasm with at least 2 different cell lines of differentiation. 1,18 To the authors' knowledge, only 1 case of mesenchymoma in a ferret has been previously reported. 6 In dogs, malignant mesenchymoma has been reported in the abdominal cavity, 22 heart, 13 liver, 14 thigh, 17 and mandible.…”

Splenic malignant mesenchymoma in a dog - immunophenotypic features and clinicopathological ramifications: a case report

“…Radiotherapy in malignant mesenchymomas is useful in primary sites, where the risk of postoperative local recurrence is high due to micro-invasion of residual cells, especially when the surgery is performed only within tight margins (Murphy et al 2006). Chemotherapy has been reported in mesenchymomas as an attempt to decrease the likelihood of metastatic spread (Robinson et al 1998;Murphy et al 2006), or to achieve a partial regression of the disease (Hahn and Richardson 1989). However, the insufficient number of cases and unspecified approach to complex cell element origins and their differentiation make a definitive conclusion regarding its effectiveness elusive.…”

“…The metastatic rate reported in this pathological study was 57% and tumour-related deaths were at 83%. Findings from the other documented primary tumor sites indicate high metastatic rate (McDonald and Helman 1986;Hahn and Richardson 1989;Robinson et al 1998;Murphy et al 2006;Gomez-Laguna et al 2012). With respect to the described metastatic potential of various soft tissue sarcomas (Liptak and Forrest 2007), two individual tumour components (myxosarcomatous and liposarcomatous) have generally low metastatic potential and one (leiomyosarcomatous) moderate, mostly to the lungs, which corresponds to findings published by Kuntz et al (1997), but also to the liver, spleen, kidney, mesentery and lymph nodes.…”

“…These tumours consist of multiple cell types and matrix components of mesenchymal origin, including osteoid, chondroid, and collagen (Spangler et al 1994;Dennis et al 2011). Abdominal, thoracic, skeletal, and submandibular malignant mesenchymomas have been reported in dogs (McDonald and Helman 1986;Hahn and Richardson 1989;Robinson et al 1998;Machida et al 2003;Murphy et al 2006;Petterino et al 2010;Gomez-Laguna et al 2012). These tumours have a slower growth rate, but tend to become very large (Moore et al 1983).…”