Abstract：
A 12-year-old spayed female Dalmatian presented with acute vomiting and anorexia. The clinicopathological and imaging abnormalities included icterus, biliary obstruction, and multiple diffuse splenic hypoechogenic nodules. Cholecystectomy was performed to remove the obstruction, followed by liver biopsy and splenectomy. Histopathological and immunohistology evaluation of the spleen, liver, and gallbladder revealed splenic marginal zone lymphoma (MZL) with gallbladder and hepatic infiltration of neoplastic CD20/CD79α-positive cells. Moreover, we observed clonal rearrangements of the immunoglobulin heavy-chain (IgH) gene in all three tissues. The dog was in good condition without chemotherapy. However, there was progressive elevation of liver enzymes, which could be attributed to neoplastic hepatic infiltration. Chlorambucil and prednisolone were administered until day 108, when the liver enzyme levels normalized. On day 156, the dog developed diffuse large B-cell lymphoma (DLBCL) of the peripheral lymph nodes. Sequence analysis of the clonally rearranged IgH gene revealed that all neoplastic cells in the spleen, gallbladder, and liver at initial presentation, as well as lymph nodes on day 156, possessed the same sequence identity of the amplified IgH fragments. This demonstrated that all neoplastic cells were derived from the same B-lymphocyte clone. The DLBCL was considered to have transformed from the splenic MZL, with gallbladder involvement. In cases of splenic MZL, it is important to consider gallbladder involvement and transformation to DLBCL. Moreover, gallbladder lymphoma should be included in the differential diagnosis of dogs with gallbladder abnormalities. Further studies are warranted to investigate the prognosis of splenic MZL.
摘要：
一名12岁的女性斑点狗出现急性呕吐和厌食症。临床病理和影像学异常包括黄疸，胆道梗阻,和多发性弥漫性脾低回声结节。进行了胆囊切除术以移除阻塞物,其次是肝活检和脾切除术。脾脏的组织病理学和免疫组织学评估，肝脏,胆囊显示脾边缘区淋巴瘤（MZL）伴胆囊和肿瘤CD20/CD79α阳性细胞浸润。此外，我们在所有三种组织中观察到免疫球蛋白重链（IgH）基因的克隆重排。这只狗在没有化疗的情况下状况良好。然而,肝酶逐渐升高,这可能归因于肿瘤性肝浸润。施用苯丁酸氮芥和泼尼松龙直到第108天,此时肝酶水平恢复正常。在第156天,狗发生外周淋巴结的弥漫性大B细胞淋巴瘤(DLBCL)。克隆重排的IgH基因的序列分析显示，脾脏中的所有肿瘤细胞，胆囊,和肝脏在最初的表现，以及第156天的淋巴结，与扩增的IgH片段具有相同的序列同一性。这表明所有肿瘤细胞都来自相同的B淋巴细胞克隆。DLBCL被认为是从脾MZL转化而来的，胆囊受累。在脾MZL的情况下，重要的是要考虑胆囊受累和向DLBCL的转化。此外，胆囊淋巴瘤应纳入胆囊异常犬的鉴别诊断。需要进一步的研究来探讨脾MZL的预后。
