Jenkins Tiffany L, Agnew Dalen, Rissi Daniel R
Department of Veterinary Biosciences, The Ohio State University College of Veterinary Medicine, Columbus, OH (Jenkins).
Diagnostic Center for Population and Animal Health, Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, Lansing, MI (Agnew).
J Vet Diagn Invest. 2018 Jul;30(4):593-597. doi: 10.1177/1040638718768373. Epub 2018 Apr 9.
A fibroblastic osteosarcoma with epithelioid and squamous differentiation in the distal femur of a 9-y-old spayed female Greyhound dog is described. Grossly, the tumor consisted of a pale-white, firm-to-hard mass that replaced the medullary and cortical areas of the distal end of the right femur. Histologically, the mass was composed predominantly of spindle cells admixed with areas of mineralized and non-mineralized osteoid matrix that were surrounded by stellate osteoblasts and scattered multinucleate giant cells, consistent with the diagnosis of a fibroblastic osteosarcoma. In addition, well-demarcated clusters of neoplastic epithelioid cells and foci of squamous differentiation with keratin pearls were present throughout the neoplasm. The spindle cells, epithelioid cells, and areas of squamous differentiation expressed cytoplasmic immunostaining for osteocalcin and osteonectin. The spindle cells and epithelioid cells were also immunopositive for vimentin. Epithelioid cells also expressed occasional cytoplasmic immunostaining for pancytokeratin (PCK) Lu-5, and areas of squamous differentiation were immunoreactive for PCK Lu-5 and high molecular weight CK; these areas were inconsistently immunoreactive for CK 5-6 and immunonegative for low molecular weight CK. Foci of squamous differentiation were not located within blood or lymphatic vessels, given that no immunoreactivity for factor VIII-related antigen was observed around these areas. A thorough autopsy and an evaluation of the medical history excluded a primary carcinoma or other neoplasm elsewhere in the dog. The findings were consistent with a diagnosis of fibroblastic osteosarcoma with epithelioid and squamous differentiation.
本文描述了一只9岁绝育雌性灵缇犬股骨远端的成纤维细胞性骨肉瘤，伴有上皮样和鳞状分化。大体上，肿瘤为灰白色、质地硬的肿块，取代了右股骨远端的髓质和皮质区域。组织学上，肿块主要由梭形细胞组成，并混有矿化和未矿化的类骨质基质区域，周围有星状成骨细胞和散在的多核巨细胞，符合成纤维细胞性骨肉瘤的诊断。此外，肿瘤内可见界限清楚的肿瘤上皮样细胞簇以及伴有角化珠的鳞状分化灶。梭形细胞、上皮样细胞和鳞状分化区域对骨钙素和骨连接蛋白呈细胞质免疫染色阳性。梭形细胞和上皮样细胞波形蛋白免疫染色也呈阳性。上皮样细胞偶尔对全细胞角蛋白（PCK）Lu-5呈细胞质免疫染色阳性，鳞状分化区域对PCK Lu-5和高分子量细胞角蛋白免疫反应阳性；这些区域对CK 5-6免疫反应不一致，对低分子量细胞角蛋白免疫阴性。鳞状分化灶不在血管或淋巴管内，因为在这些区域周围未观察到因子VIII相关抗原的免疫反应性。全面的尸检和病史评估排除了犬体内其他部位的原发性癌或其他肿瘤。这些发现符合伴有上皮样和鳞状分化的成纤维细胞性骨肉瘤的诊断。
