Primary Ovarian Rhabdomyosarcoma in a Dog

Aggressive, Solid Variant of Alveolar Rhabdomyosarcoma with Cutaneous Involvement in a Juvenile Labrador Retriever

“…The present case had a solid variant ARMS composed of poorly differentiated cells without cross striations and with no evidence of differentiation into myoblasts or myotube-like cells. ARMS cells usually express skeletal muscle markers, such as desmin, MyoD1 and myogenin, and as mesenchymal cells, they also express vimentin (Sarnelli et al, 1994;Kim et al, 1996;Cooper and Valentine, 2002;Bae et al, 2007;Murakami et al, 2010;Snyder and Michael, 2011;Boeloni et al, 2012;Kimura et al, 2013), as in our case. However, in undifferentiated or poorly differentiated rhabdomyosarcomas, desmin expression may be weak or absent (Carter et al, 1989;Cooper and Valentine, 2002;Murakami et al, 2010).…”

“…In all of these cases, the tumour mass was diagnosed first in the maxillofacial region, which may show a predisposition for ARMS. Canine ARMS is considered to be locally invasive (Sarnelli et al, 1994;Kim et al, 1996;Cooper and Valentine, 2002;Snyder and Michael, 2011;Boeloni et al, 2012;Kimura et al, 2013) and only four cases of distant metastasis have been observed (Seibold, 1974;Bae et al, 2007;Murakami et al, 2010;Boeloni et al, 2012). The behaviour of the present tumour was very aggressive, with metastases to most of the organs of the abdomen and thorax and to skeletal muscle.…”

“…In man, ARMS is highly aggressive, prone to metastasis and carries a poor prognosis, occurring predominantly in adolescents, with a predilection for the extremities, paraspinal and perineal regions and the paranasal sinuses (Parham and Barr, 2002). Until now, only nine cases of ARMS have been documented in dogs aged 7 months to 10 years, with a predilection for the gingiva, subcutaneous maxillary area, uterus, ovary and omentum (Seibold, 1974;Sarnelli et al, 1994;Kim et al, 1996;Cooper and Valentine, 2002;Bae et al, 2007;Murakami et al, 2010;Snyder and Michael, 2011;Boeloni et al, 2012;Kimura et al, 2013). Distant metastasis to the brain, lung and abdominal viscera was observed in only four of the cases.…”

“…Mature striated muscles do not express smooth muscle markers, but they can be observed in myoblasts during the early stage of muscle development (Kimura et al, 2013). In most of the cases of ARMS in dogs, the expression of smooth muscle markers was absent (Cooper and Valentine, 2002;Bae et al, 2007;Murakami et al, 2010;Boeloni et al, 2012). Only two cases of canine ARMS with variable positive SMA labelling of the tumour cells have been published (Cooper and Valentine, 2002;Kimura et al, 2013).…”

A laryngeal rhabdomyosarcoma in a dog

“…RM/RMS represents only 0.07 per cent of all tumours encountered in animals and laryngeal tumours are relatively rare in dogs with a 0.02 per cent frequency (Liggett and others 1985, Clercx and others 1998, Snyder and Michael 2011, Yamate and others 2011, Boeloni and others 2012, Dunbar and others 2012, Caserto 2013, Kimura and others 2013). Few cases have been described in the literature (Clercx and others 1998, Dunbar and others 2012, Caserto 2013).…”