Brunetti Barbara, Muscatello Luisa Vera, DeTolla Louis J, Avallone Giancarlo
Department of Veterinary Medical Sciences, University of Bologna, Italy.
University of Maryland, School of Medicine, Baltimore, MD, USA.
Case Rep Vet Med. 2021 Jan 23;2021:6615256. doi: 10.1155/2021/6615256. eCollection 2021.
This report describes an unusual mesenchymal differentiation in a canine benign mixed mammary tumour. A 13-year-old crossbreed female dog was submitted to surgery to remove an inguinal mammary nodule. The tumour was composed of mammary epithelium and mesenchymal populations, not only of cartilage and bone but also of myoid cells. PTAH demonstrated cross striation of striated muscle, and immunohistochemistry highlighted striated muscle expressing desmin and calponin, and smooth muscle expressing desmin, SMA, and calponin. The tumour was diagnosed as a benign mixed tumour with leio- and rhabdomyoid differentiation. There was no tumour recurrence after one year of clinical follow-up. In conclusion, the well-differentiated features of leiomyocytes and rhabdomyocytes and the growth pattern define the benign origin of the mesenchymal component, which has been confirmed by a benign outcome; therefore, the knowledge of this kind of differentiation is helpful to avoid misdiagnoses.
本报告描述了一例犬良性混合性乳腺肿瘤中不寻常的间充质分化。一只13岁的杂种雌性犬接受手术切除腹股沟乳腺结节。肿瘤由乳腺上皮和间充质成分组成，不仅有软骨和骨，还有肌样细胞。磷钨酸苏木精（PTAH）显示横纹肌的横纹，免疫组织化学突出显示表达结蛋白和钙调蛋白的横纹肌，以及表达结蛋白、平滑肌肌动蛋白（SMA）和钙调蛋白的平滑肌。该肿瘤被诊断为具有平滑肌瘤样和横纹肌瘤样分化的良性混合性肿瘤。临床随访一年后无肿瘤复发。总之，平滑肌瘤细胞和横纹肌瘤细胞的良好分化特征以及生长模式确定了间充质成分的良性起源，这已通过良性结果得到证实；因此，了解这种分化有助于避免误诊。
