Original ArticlesCyclin D1-negative Blastoid Mantle Cell Lymphoma Identified by SOX11 ExpressionZeng, Weifen MD, PhD*; Fu, Kai MD, PhD†; Quintanilla-Fend, Leticia MD, PhD‡; Lim, Megan MD, PhD§; Ondrejka, Sarah DO*; Hsi, Eric D. MD*Author Information *Department of Clinical Pathology, Cleveland Clinic, Cleveland, OH †Department of Pathology, University of Nebraska Medical Center, Omaha, NE ‡Institute of Pathology, Eberhard-Karls-University of Tübingen, Tübingen, Germany §Department of Pathology, University of Michigan, Ann Arbor, MI Conflicts of Interest and Source of Funding: The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article. Correspondence: Eric D. Hsi, MD, Department of Clinical Pathology, Cleveland Clinic, 9500 Euclid Ave, L11, Cleveland, OH 44195 (e-mail:email@example.com). The American Journal of Surgical Pathology: February 2012 - Volume 36 - Issue 2 - p 214-219 doi: 10.1097/PAS.0b013e318241f050 Buy SDC Metrics Abstract SOX11 expression has been recently shown to be useful in the diagnosis of mantle cell lymphoma (MCL), including cyclin D1-negative MCL with typical morphology. We evaluated SOX11 expression pattern in B-cell non-Hodgkin lymphoma (B-NHL) subtypes to confirm specificity and used it as a feature to identify the first reported cases of cyclin D1-negative blastoid MCL. SOX11 expression was evaluated by immunohistochemistry in 140 cases of mature B-NHL, including 4 cases of suspected blastoid MCL that lacked cyclin D1 expression and 8 cases of CD5-positive diffuse large B-cell lymphoma (DLBL). In addition, 5 cases of B or T lymphoblastic lymphoma were included. Nuclear expression of SOX11 was found in cyclin D1-positive MCL (30/30, 100%) and in a case of cyclin D1-negative MCL with typical morphology. SOX11 was also expressed in Burkitt lymphoma (1/5, 20%) and lymphoblastic lymphoma (2/3 T-LBLs, 2/2 B-LBLs, overall 4/5, 80%), whereas all cases of DLBL (including CD5+ DLBL) and other small B-NHL were negative. The 4 suspected cases of blastoid MCL were also SOX11+. These cases had a complex karyotype that included 12p abnormalities. We confirmed prior reports that stated that SOX11 nuclear expression was a specific marker for MCL, including cyclin D1-negative MCL with typical morphology. To our knowledge, this is the first report regarding its use in identifying cases of cyclin D1-negative blastoid MCL. Routine use of SOX11 in cases of suspected CD5+ DLBL might help identify additional cases of cyclin D1-negative blastoid MCL. © 2012 Lippincott Williams & Wilkins, Inc.