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Int J Clin Exp Pathol 2013;6(11):2631-2635

Case Report
Anaplastic lymphoma kinase-positive large B-cell lymphoma: a case report with
emphasis on the cytological features of the pleural effusion

Mitsuaki Ishida, Keiko Yoshida, Akiko Kagotani, Muneo Iwai, Miyuki Yoshii, Hiroko Okuno, Akiko Horinouchi, Ryota Nakanishi, Ayumi Harada,
Takashi Yoshida, Takafumi Okuno, Keiko Hodohara, Hidetoshi Okabe

Department of Clinical Laboratory Medicine, Division of Diagnostic Pathology, Department of Hematology, Shiga University of Medical Science,
Shiga, Japan

Received August 29, 2013; Accepted October 3, 2013; Epub October 15, 2013; Published November 1, 2013

Abstract: Anaplastic lymphoma kinase (ALK)-positive large B-cell lymphoma (ALK-positive LBCL) is an extremely rare distinct
clinicopathological subtype of LBCL, characterized by the presence of ALK-positive monomorphic large immunoblast-like neoplastic B cells.
Herein, we describe the first cytological report on ALK-positive LBCL in the pleural effusion. A 69-year-old Japanese male with a past history of
malignant lymphoma of the cecum presented with progressive dyspnea and pleural effusion. Removal of the pleural effusion and aspiration of
bone marrow were performed. May-Grünwald-Giemsa stain of the pleural fluid revealed abundant single or small aggregates of large-sized
round cells. These cells had centrally-located large round to oval nuclei. The peculiar finding was the presence of pseudopodial cytoplasmic
projections, and some neoplastic cells had eosinophilic pseudopodial cytoplasmic projections, which resembled “flaming plasma cells”.
Histopathological and immunohistochemical studies of the bone marrow demonstrated CD138+, ALK1+, CD20-, CD79a-, CD30-, and IgA+
large-sized neoplastic cells. Therefore, a diagnosis of ALK-positive LBCL was made. The peculiar finding of the present case was that most of
the neoplastic cells had pseudopodial cytoplasmic projections, and some of them had eosinophilic pseudopodial cytoplasmic projections that
resembled “flaming plasma cells”, which has been recognized as the characteristic finding of IgA myeloma. Therefore, tumor cells that
resembled “flaming plasma cells” in the pleural effusion may have had IgA in the cytoplasm. Albeit extremely rare, ALK-positive LBCL shows
aggressive clinical course, thus, recognition of the cytomorphological features of this type of malignant lymphoma is important for early and
correct diagnosis. (IJCEP1308070).

Keywords: ALK-positive large B-cell lymphoma, pleural effusion, pseudopodial cytoplasmic projection

Address correspondence to: Dr. Mitsuaki Ishida, Department of Clinical Laboratory Medicine and Division of Diagnostic Pathology, Shiga
University of Medical Science, Tsukinowa-cho, Seta, Otsu, Shiga, 520-2192, Japan. Tel: +81-77-548-2603; Fax: +81-77-548-2407; E-mail:
mitsuaki@belle.shiga-med.ac.jp