Parachini-Winter Cyril, Curran Kaitlin M, Russell Duncan S, Gorman Elena
Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon.
Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon.
Vet Clin Pathol. 2018 Dec;47(4):643-648. doi: 10.1111/vcp.12657. Epub 2018 Sep 19.
A 9-year-old spayed female Curly Coated Retriever was referred for evaluation of generalized peripheral lymphadenomegaly. The dog was clinically healthy on presentation with no anomalies detected on complete blood count, serum biochemistry, urinalysis, or three-view thoracic radiographs. Fine-needle aspiration (FNA) and cytology of the peripheral lymph nodes were consistent with lymphoma with an intermediate-sized lymphoid population. Flow cytometry of peripheral lymph nodes was consistent with a homogeneous population of CD4 T cells that had lost expression of the pan-leukocyte antigen CD45. Variable expression of CD21, CD25, and class II major histocompatibility complex (MHC) were also noted. This was considered consistent with T-zone lymphoma (TZL), although the T cells were noted to be larger than usual based on flow cytometry. Due to the suspected indolent nature of this patient's disease and clinical progression, a careful monitoring approach was initially discussed with the owner. However, additional diagnostic testing was performed to confirm the diagnosis. Bone marrow cytology did not show any significant anomalies. The largest lymph node (left mandibular) was extirpated and submitted for histopathology. Based on the lymph node architecture, cellular features, and high mitotic activity, an unexpected diagnosis of peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) was made. The dog was started on CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy. This case illustrates the limitations of using flow cytometry as the sole means of diagnosing TZL and highlights the importance of using complementary tests when subtyping canine lymphoma, which is significant when considering a patient's treatment plan and prognosis.
一只9岁已绝育的卷毛寻回犬因全身性外周淋巴结肿大前来接受评估。该犬就诊时临床健康，全血细胞计数、血清生化检查、尿液分析或胸部正侧位X线片均未发现异常。外周淋巴结细针穿刺（FNA）及细胞学检查结果符合淋巴瘤，淋巴细胞群体中等大小。外周淋巴结流式细胞术显示为均一的CD4 T细胞群体，其全白细胞抗原CD45表达缺失。还发现CD21、CD25和II类主要组织相容性复合体（MHC）表达各异。尽管流式细胞术显示T细胞比正常大，但这仍被认为符合T区淋巴瘤（TZL）。鉴于怀疑该患犬病情发展缓慢且具有临床进展性，最初与犬主讨论了采用密切监测的方法。然而，为确诊仍进行了额外的诊断性检查。骨髓细胞学检查未发现任何明显异常。切除最大的淋巴结（左下颌淋巴结）并送去做组织病理学检查。根据淋巴结结构、细胞特征及高有丝分裂活性，意外诊断为未另行特指的外周T细胞淋巴瘤（PTCL-NOS）。该犬开始接受CHOP（环磷酰胺、阿霉素、长春新碱和泼尼松）化疗。本病例说明了将流式细胞术作为诊断TZL的唯一手段的局限性，并强调了在犬淋巴瘤亚型分类时使用补充检查的重要性，这在考虑患犬的治疗方案和预后时意义重大。
