Hickey Jillian, Harris R Adam, Meola Stacy D, Jennings Samuel, Moore Peter F, Vernau William, Harding Kayla, Thamm Douglas H, Schlein Lisa J
Wheat Ridge Animal Hospital, Wheat Ridge, CO, USA.
Veterinary Diagnostic Laboratory-Microbiology, Immunology, Pathology, Colorado State University, Fort Collins, CO, USA.
J Vet Diagn Invest. 2025 Mar;37(2):317-323. doi: 10.1177/10406387241312308. Epub 2025 Jan 27.
An 8-y-old, spayed female Bernese Mountain Dog was presented to a referral center for evaluation of right thoracic limb lameness and previously suspected Evans syndrome that had been poorly responsive to immunosuppressive therapy. Based on review of examination findings and laboratory data, Evans syndrome was deemed unlikely and hemophagocytic histiocytic sarcoma (HHS) was strongly suspected. On blood smear evaluation, atypical, histiocytic cells were noted, some of which exhibited siderophagia. Considering that circulating cells are not typically observed in dogs with HHS, additional diagnostic investigation was performed. Autopsy and histopathology revealed that the dog had a mixed form of HS (dendritic-cell origin HS in the lung, and HHS in the spleen, liver, and bone marrow), and immunocytochemical characterization of cultured cells derived from blood suggested that the cells were of dendritic HS origin, rather than HHS origin, as originally suspected. Whole-exome sequencing revealed genetic similarity between cell lines derived from lung tissue and blood, providing additional evidence of the relatedness of these 2 cell populations. Our case highlights the rare entity of mixed HS and typifies the inherent challenges in classifying rare, atypical, circulating neoplastic cells.
一只8岁已绝育的雌性伯恩山犬被转诊至一家转诊中心，以评估其右前肢跛行情况，该犬之前疑似患有伊文氏综合征，对免疫抑制治疗反应不佳。根据检查结果和实验室数据回顾，伊文氏综合征可能性不大，强烈怀疑为噬血细胞性组织细胞肉瘤（HHS）。在血液涂片评估中，发现了非典型的组织细胞，其中一些表现出噬铁现象。考虑到HHS患犬通常不会出现循环细胞，因此进行了进一步的诊断调查。尸检和组织病理学检查显示，该犬患有混合型组织细胞肉瘤（肺内为树突状细胞起源的组织细胞肉瘤，脾脏、肝脏和骨髓内为噬血细胞性组织细胞肉瘤），对血液来源的培养细胞进行免疫细胞化学特征分析表明，这些细胞起源于树突状组织细胞肉瘤，而非最初怀疑的噬血细胞性组织细胞肉瘤。全外显子测序揭示了肺组织和血液来源的细胞系之间的基因相似性，为这两个细胞群体的相关性提供了额外证据。我们的病例突出了混合型组织细胞肉瘤这一罕见实体，并体现了对罕见、非典型循环肿瘤细胞进行分类时固有的挑战。
