Expression of CD5 in salivary gland tumors: an ancillary marker for carcinoma showing thymus-like differentiation (CASTLE) of the major salivary gland

Eiichi Sasaki; Hoshino Terada; Naoki Oishi; Akari Iwakoshi; Katsuhiro Masago; Hirokazu Matsushita; Hidetaka Yamamoto; Nobuhiro Hanai; Hisashi Tateyama

doi:10.1007/s00428-023-03701-8

Expression of CD5 in salivary gland tumors: an ancillary marker for carcinoma showing thymus-like differentiation (CASTLE) of the major salivary gland

Virchows Arch. 2023 Nov 13. doi: 10.1007/s00428-023-03701-8. Online ahead of print.

Authors

Eiichi Sasaki^{1

2

3}, Hoshino Terada⁴, Naoki Oishi⁵, Akari Iwakoshi^{6

7}, Katsuhiro Masago⁸, Hirokazu Matsushita⁹, Hidetaka Yamamoto¹⁰, Nobuhiro Hanai⁴, Hisashi Tateyama¹¹

Affiliations

¹ Department of Pathology and Molecular Diagnostics, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-Ku, Nagoya, Aichi, 464-8681, Japan. sasakia1es@gmail.com.
² Clinical Research Center, National Hospital Organization Nagoya Medical Center, Nagoya, Japan. sasakia1es@gmail.com.
³ Division of Translational Oncoimmunology, Aichi Cancer Center Research Institute, Nagoya, Japan. sasakia1es@gmail.com.
⁴ Department of Head and Neck Surgery, Aichi Cancer Center Hospital, Nagoya, Japan.
⁵ Department of Pathology, University of Yamanashi, Chuo, Japan.
⁶ Clinical Research Center, National Hospital Organization Nagoya Medical Center, Nagoya, Japan.
⁷ Department of Pathology, National Hospital Organization Nagoya Medical Center, Nagoya, Japan.
⁸ Department of Pathology and Molecular Diagnostics, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-Ku, Nagoya, Aichi, 464-8681, Japan.
⁹ Division of Translational Oncoimmunology, Aichi Cancer Center Research Institute, Nagoya, Japan.
¹⁰ Department of Pathology, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Okayama, Japan.
¹¹ Department of Pathology, Clinical Laboratory, Kasugai Municipal Hospital, Kasugai, Japan.

PMID: 37953373
DOI: 10.1007/s00428-023-03701-8

Abstract

Recently, cases of carcinoma showing thymus-like differentiation (CASTLE) occurring in major salivary glands have been identified. To assess the diagnostic value of CD5 immunohistochemistry in distinguishing salivary CASTLE from other types of salivary gland tumors, we evaluated CD5 expression in 109 salivary gland tumors, encompassing 23 different histological types, including salivary CASTLE. In addition, we reviewed 10 previously reported cases of salivary CASTLE. Most salivary CASTLE cases (10/11, 91%) showed strong CD5 expression. In contrast, 104 of 108 (96%) non-salivary CASTLE tumors were negative for CD5, while the remaining four tumors (3.7%), all of which were histologically Warthin tumors, showed focal positivity for CD5 with weak to moderate intensity. In conclusion, the findings in this study support the potential use of CD5 immunohistochemistry for distinguishing salivary CASTLE from other histological types of salivary gland tumors. Aberrant CD5 expression in this tumor may be linked to the tumor microenvironment.

Keywords: CASTLE; CD5; Intercalated duct; Intrasalivary thymic carcinoma; NRAS; Warthin tumor.