A case of anaplastic lymphoma kinase-positive large B-cell lymphoma: Aspiration cytology findings

Anaplastic lymphoma kinase-positive large B-cell lymphoma (ALK + LBCL): a systematic review of clinicopathological features and management

Anaplastic lymphoma kinase-positive (ALK+) large B-cell lymphoma (LBCL) is a rare CD20-negative aggressive lymphoma. Given its rarity, data on ALK + LBCL are scarce and limited to case reports and small case series. Our systematic review included 184 unique cases published in the literature and shows that ALK + LBCL can affect individuals at any age, has a male predominance and is not associated with chronic viral infections. The malignant cells express ALK, VS38c, BLIMP-1, EMA, c-MYC, and BOB-1. The STAT3/STAT5, PI3K/AKT, PLCG2, and ERK pathways are important in the pathophysiology of ALK + LBCL. The prognosis of ALK + LBCL is poor with a 5-year survival rate of 28%. Early disease stage is associated with better outcomes. ALK inhibitors and other targeted agents could be of value in the treatment of ALK + LBCL. Additional research is needed to better understand, diagnose and treat ALK + LBCL.

ALK-positive Large B-cell Lymphoma: A Clinicopathologic Study of 26 Cases With Review of Additional 108 Cases in the Literature

Anaplastic lymphoma kinase-positive large B-cell lymphoma (ALK LBCL) is a rare, aggressive subtype of diffuse large B-cell lymphoma with characteristic ALK rearrangements. Diagnosis of ALK LBCL can be challenging because of its rarity, unique morphologic characteristics, and unusual immunophenotypic features, which significantly overlap with other hematologic and nonhematologic neoplasms. The purpose of this study is to further explore the clinicopathologic features of ALK LBCL to ensure the awareness and accurate diagnosis of this entity. We retrospectively reviewed the data from 26 cases in our institutions and additional 108 cases from the literature. ALK LBCL typically occurred in the lymph nodes of young and middle-aged, immunocompetent patients. The medium age was 35 years with a male to female ratio of 3.5:1. Vast majority of cases showed immunoblastic and/or plasmablastic morphology. All cases expressed ALK protein with a cytoplasmic granular pattern in most of them. Common B-cell markers (CD20, CD79a, and PAX5) were typically negative, but the tumor cells mostly expressed 2 B-cell transcriptional factors, BOB1 and OCT2. The 5-year overall survival (OS) was 34%, and the median survival was 1.83 years. In patients with stage III/IV disease, the 5-year OS was only 8%. Moreover, patients below 35 years of age had a significantly better OS than those aged 35 years or above.

Cytologic perspectives on neoteric B-cell lymphoproliferative disorders

The 2008 World Health Organization (WHO) classification of hematopoietic and lymphoid tissues has been recently revised, and publication of the updated 2016 version is expected soon. Given that cytopathologists are often involved in the diagnosis of primary, recurrent, and transformed lymphoproliferative disorders, knowledge of updates to the WHO lymphoma classification, including terminology, pathogenesis, ancillary techniques, and targeted therapies is necessary. Herein, we reference the last decade of cytology specific literature for seven newer B-cell disorders and provide illustrative examples of each entity from our files.

Anaplastic lymphoma kinase positive large B-cell lymphoma: Literature review and report of an endoscopic fine needle aspiration case with tigroid backgrounds mimicking seminoma

Anaplastic lymphoma kinase-positive large B-cell lymphoma (ALK+ LBCL) is a rare distinct type of non-Hodgkin's lymphoma that arises in association with alterations of the ALK gene. This distinct disease entity is typically associated with an aggressive clinical course and appears in light microscopic preparations as a monomorphic population of large, immunoblast-like cells. In this report, we describe a case of ALK+ LBCL diagnosed by transgastric endoscopic ultrasound-guided fine needle aspiration (EUS FNA) of splenic hilar lymph nodes. Modified Giemsa stained direct smears from the FNA sample demonstrated large lesional cells with foamy cytoplasm and macronucleoli admixed with small lymphocytes in tigroid backgrounds, mimicking the cytologic appearance of seminoma. Ancillary immunohistochemical studies subsequently confirmed the diagnosis of ALK+ LBCL with the lesional cells being immunoreactive for CD138, VS38c, MUM1, ALK1, and lambda light chain. The cohesiveness of the cells, the cellular morphology, and the tigroid backgrounds were all pitfalls for accurate diagnosis of this rare specific type of lymphoid malignancy by cytology. To our knowledge this is the first case report detailing the diagnosis of ALK+ LBCL by EUS FNA and the first report describing a glycogen-rich tigroid background in direct FNA smears. Establishing a refined diagnosis in cases of this rare form of LBCL is necessary, as therapies targeting ALK may be of value in clinical management. Diagn. Cytopathol. 2017;45:148-155. © 2016 Wiley Periodicals, Inc.