Low Molecular Weight Cytokeratin Immunohistochemistry Reveals That Most Salivary Gland Warthin Tumors and Lymphadenomas

  • PDF / 1,723,901 Bytes
  • 5 Pages / 595.276 x 790.866 pts Page_size
  • 120 Downloads / 188 Views

DOWNLOAD

REPORT


ORIGINAL PAPER

Low Molecular Weight Cytokeratin Immunohistochemistry Reveals That Most Salivary Gland Warthin Tumors and Lymphadenomas Arise in Intraparotid Lymph Nodes Anne C. McLean‑Holden1,2 · Justin A. Bishop1  Received: 13 July 2020 / Accepted: 21 August 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020

Abstract The nature of the lymphoid stromal component in Warthin tumor and lymphadenoma of the parotid gland has been a controversial topic in salivary gland pathology for decades. Two theories exist: first, that these tumors arise from salivary gland inclusions within intraparotid lymph nodes; and second, that they arise within salivary gland parenchyma and induce tumorassociated lymphoid proliferation (TALP). A recent study demonstrated that low molecular weight cytokeratin is effective in distinguishing salivary gland tumors within lymph nodes from those inducing TALP via identification of extrafollicular reticulum cells, which are only found in true lymph nodes. Twenty-one Warthin tumors and 4 lymphadenomas were retrieved from the archives of the Department of Pathology at University of Texas Southwestern Medical Center. Cam5.2 immunohistochemistry was performed on each case and independently evaluated by two pathologists. Extrafollicular reticulum cells were identified by Cam5.2 immunostaining in 21 of 21 Warthin tumors (100%), and 3 of 4 lymphadenomas (75%). Extrafollicular reticulum cells were consistently localized to the perisinusoidal and paracortical areas of the lesions studied. Extrafollicular reticulum cells were identified via low molecular weight cytokeratin Cam5.2 immunohistochemistry in all of the Warthin tumors and most of the lymphadenomas evaluated. This finding strongly supports the notion that these most if not all of these tumors arise within intraparotid lymph nodes, presumably from salivary gland inclusions entrapped during embryonic development. Keywords  Warthin tumor · Lymphadenoma · Cam5.2 · Cytokeratin · Lymph node · Salivary gland

Introduction Warthin tumor is one of the most common salivary gland neoplasms. It is comprised of a cystic and papillary epithelial component with a well-organized double-layer of oncocytic cells, as well as a lymphoid stroma that is usually prominent [1]. Lymphadenoma is a rare salivary gland tumor that shares many features with Warthin tumor, particularly the presence of epithelial and lymphoid tumor components [2]. Indeed, some tumors demonstrate mixed features of both * Justin A. Bishop [email protected] 1



Department of Pathology, University of Texas Southwestern Medical Center, 6201 Harry Hines Blvd, Dallas, TX 75390, USA



Department of Pathology, Emory University, Atlanta, GA, USA

2

Warthin tumor and lymphadenoma, supporting the idea that they are related neoplasms [3, 4]. Lymphadenomas are subclassified based on the presence or absence of sebaceous differentiation. The nature of the lymphoid component within Warthin tumor and lymphadenoma has been debated by both oral and head and neck pathologis