Aggressive spindle cell rhabdomyosarcoma in an 11-month-old boxer dog.
Rhabdomyosarcoma (RMS) is a malignant neoplasm derived from mesenchymal tissue with a tendency toward myogenic differentiation associated with the embryogenesis of skeletal muscle. According to the histological features, it can be classified in embryonal, botryoid, alveolar, and pleomorphic, which usually correspond to clinical behavior and prognosis. The spindle cell (SCRMS) variant is a rare subtype of the embryonal RMS and is considered to be less aggressive lesion. The aim of the present paper is to report an unusual case of SCRMS in an 11-month-old male boxer dog diagnosed as extensive SCRMS that affected the frontal region of the skull. Due to the aggressive nature of the lesion and poor clinical prognosis the dog's owners preferred euthanasia as a treatment. A full postmortem examination was carried out. Microscopically, the lesion was composed of a highly cellular proliferation of spindle cells arranged in long and intersecting fascicles. After performing the immunohistochemical studies (HHF-35, smooth muscle actin, desmin and MyoD1), the present case was diagnosed as SCRMS.
da Roza
Marcello Rodrigues
MR
School of Veterinary Medicine, Federal University of Goiás, Goiânia-GO, Brazil. marcelloroza@gmail.com
de Amorim
Rivadávio Fernandes Batista
RF
Carneiro
Fabiana Pirani
FP
Benatto
Nara
N
Barriviera
Mauricio
M
Miguel
Márcia Cristina da Costa
MC
D000818:Animals; D001344:Autopsy; D003893:Desmin / Q000032:analysis; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005065:Euthanasia; D008297:Male; D008437:Maxilla / Q000473:pathology; D018233:Rhabdomyosarcoma, Embryonal / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D012886:Skull / Q000473:pathology
D003893:Desmin