Lin Oscar, Koreishi Aashiyana, Brandt Suzanne M, Arcila Maria, Teruya-Feldstein Julie
Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.
Diagn Cytopathol. 2013 May;41(5):404-7. doi: 10.1002/dc.22830. Epub 2012 Feb 20.
Anaplastic lymphoma kinase positive large B-cell lymphoma (ALK+ LBCL) was recognized as a distinct entity by the 2008 WHO classification of lymphomas. Histologically, the tumor cells exhibit either plasmablastic or immunoblastic morphology, with characteristic granular staining for ALK. The purpose of this study is to evaluate the cytologic findings of ALK+ LBCL. The cytologic material obtained by needle biopsy from three cases of ALK+ LBCL was evaluated. All lesions were nodal and the cytologic material analyzed included air-dried and alcohol-fixed slides stained with modified Giemsa and/or HE stains. The following morphologic criteria were assessed: cellularity, cluster characteristics, cell size, cytoplasmic and nuclear characteristics, and background composition. The cytology specimens obtained from the needle biopsies were moderately to highly cellular and composed of a population of large cells with immunoblastic or plasmablastic morphology. Single cells were present in all three cases, but two cases also showed the presence of clusters with acinar and papillary architecture. Multinucleation was noted in all three cases. Amorphous metachromatic background material was noted focally in the modified Giemsa stained slides in all three cases. Immunostains performed on cytology specimens showed cytoplasmic immunoreactivity for ALK, with characteristic granular features. ALK+ LBCL is a rare recently recognized type of lymphoma with unique morphologic and immunophenotypic findings that can mimic epithelial tumors. Recognition of this potential diagnostic pitfall is critical to prevent unnecessary additional work-up and mistreatment.
间变性淋巴瘤激酶阳性大B细胞淋巴瘤（ALK+ LBCL）在2008年世界卫生组织淋巴瘤分类中被确认为一种独特的实体。组织学上，肿瘤细胞表现出浆母细胞或免疫母细胞形态，对ALK有特征性颗粒状染色。本研究的目的是评估ALK+ LBCL的细胞学表现。对3例ALK+ LBCL经针吸活检获得的细胞学材料进行评估。所有病变均为淋巴结病变，分析的细胞学材料包括用改良吉姆萨和/或苏木精-伊红染色的空气干燥和酒精固定玻片。评估了以下形态学标准：细胞密度、细胞团特征、细胞大小、细胞质和细胞核特征以及背景成分。针吸活检获得的细胞学标本细胞密度为中度至高度，由一群具有免疫母细胞或浆母细胞形态的大细胞组成。所有3例均有单个细胞，但2例还显示存在具有腺泡和乳头结构的细胞团。所有3例均观察到多核现象。在所有3例改良吉姆萨染色玻片中均局灶性观察到无定形异染性背景物质。对细胞学标本进行的免疫染色显示ALK的细胞质免疫反应性，具有特征性颗粒状特征。ALK+ LBCL是一种最近才被认识的罕见淋巴瘤类型，具有独特的形态学和免疫表型表现，可模仿上皮性肿瘤。认识到这一潜在的诊断陷阱对于避免不必要的进一步检查和错误治疗至关重要。
