Malignant mesenchymoma associated with an unusual vasoinvasive metastasis in a dog

Abstract

A case of a malignant mesenchymoma with an unusual, vasoinvasive, metastatic behavior in a three-year-old, intact female basset hound is presented. Malignant mesenchymomas are rare neoplasms in humans and in dogs. No previous reports of a malignant mesenchymoma with vasoinvasive metastasis in the dog were found in the literature. The constituent neoplasms are discussed in relation to reports in the human and veterinary literature, and a potential etiology for this unique presentation is hypothesized.

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

“…The survival time of eleven months in our patient is in accordance with the pathological evidence describing splenic primary mesenchymal neoplasms, where mesenchymomas showed the longest median survival rate of twelve months (Weinstein et al 1989;Spangler and Culbertson 1992;Spangler et al 1994). The documented survival in mesenchymomas is affected by younger patient age (Addachi et al 2003), primary localisation in the liver (McDonald and Helman 1986), vasoinvasive metastasis (Robinson et al 1998) and late diagnosis and treatment (Kaneko et al 2006). Hepatocellular adenomas are non-aggressive, usually single, smooth tumours of variable size with little clinical significance (Stalker and Hayes 2007).…”

“…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).…”

“…Malignant mesenchymomas are more likely to be reported in older individuals (Spangler et al 1994). Local recurrence and metastases in human and animal patients depend on the independent behavior of the constituent tissue present in the tumour (Schajowiez et al 1966;Liwnicz and Ferreol, 1986;Hassan et al 1994;Robinson et al 1998;Machida et al 2003;Gomez-Laguna et al 2012).…”