Lin Tzu-Yin, Hamberg Alexander, Pentecost Rebecca, Wellman Maxey, Stromberg Paul
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA.
J Vet Diagn Invest. 2010 Sep;22(5):808-11. doi: 10.1177/104063871002200531.
A 9-year-old female llama (Lama glama) that served as a blood donor at The Ohio State University Veterinary Teaching Hospital developed multiple small, raised, firm, non-haired cutaneous masses on the right hip, left cheek, and right and left shoulders. Cytological evaluation of fine-needle aspirates from the cutaneous mass from the left shoulder and right hip comprised many well-differentiated, highly granulated mast cells with moderate numbers of eosinophils. Occasional mast cells exhibited erythrophagocytosis and contained a small amount of hemosiderin or several variably sized vacuoles. A cytologic diagnosis of mast cell tumor with evidence of prior hemorrhage was made, and the masses were surgically removed. Microscopically, each mass consisted of sheets of neoplastic round cells that formed nonencapsulated nodules in the dermis and infiltrated into the adjacent dermal collagen. Eosinophils were scattered among the mast cells at the periphery of the nodules. Neoplastic mast cells, but not eosinophils, exhibited positive membrane KIT expression and cytoplasmic vimentin staining. A final diagnosis of mast cell tumor was made based on cytology, histology, and immunohistochemistry.
一只9岁的雌性美洲驼（小羊驼）在俄亥俄州立大学兽医学院教学医院作为献血者时，右侧臀部、左侧脸颊以及左右肩部出现了多个小的、凸起的、质地坚硬且无毛的皮肤肿块。对来自左肩和右臀部皮肤肿块的细针穿刺物进行细胞学评估，发现其中包含许多分化良好、颗粒高度丰富的肥大细胞以及中等数量的嗜酸性粒细胞。偶尔可见肥大细胞出现红细胞吞噬现象，并含有少量含铁血黄素或几个大小不一的空泡。做出了肥大细胞瘤伴既往出血证据的细胞学诊断，随后对肿块进行了手术切除。显微镜下，每个肿块均由成片的肿瘤性圆形细胞组成，这些细胞在真皮内形成无包膜的结节，并浸润至相邻的真皮胶原中。嗜酸性粒细胞散在于结节周边的肥大细胞之间。肿瘤性肥大细胞而非嗜酸性粒细胞呈现膜KIT表达阳性和细胞质波形蛋白染色阳性。基于细胞学、组织学和免疫组织化学最终诊断为肥大细胞瘤。
