Fukuhara, Noriaki Toranomon Hospital|Tokyo Medical and Dental University|Okinaka Memorial Institute for Medical Research
Inoshita, Naoko Toranomon Hospital|Tokyo Medical and Dental University|Okinaka Memorial Institute for Medical Research|Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology
Kitagawa, Masanobu Tokyo Medical and Dental University
Fukuhara, Hirokazu Toranomon Hospital
Tatsushima, Keita Toranomon Hospital
Yamaguchi-Okada, Mitsuo Toranomon Hospital
Takeshita, Akira Okinaka Memorial Institute for Medical Research|Toranomon Hospital
Ito, Junko Toranomon Hospital
Takeuchi, Yasuhiro Okinaka Memorial Institute for Medical Research|Toranomon Hospital
山田, 正三 Toranomon Hospital|Okinaka Memorial Institute for Medical Research|Tokyo Neurological Center
Nishioka, Hiroshi Toranomon Hospital|Okinaka Memorial Institute for Medical Research
Craniopharyngioma (CP) is mainly classified into two pathological subtypes: adamantinomatous (ACP) and papillary (PCP). CTNNB1 (β-catenin) mutations are detected in ACPs, and the BRAF V600E mutation is detected in PCPs. However, genetic analysis is not always possible in general medical practice. In this study, we investigated whether immunohistochemistry could replace genetic analysis as an aid in subtype diagnosis. Here, 38 CP patients who had undergone their first tumor resection were included. Among the 38 cases, 22 were morphologically diagnosed as ACP, 10 cases were diagnosed as PCP, and six cases were diagnosed as undetermined CP that were morphologically difficult to classify as either ACP or PCP. Results of immunohistochemistry and genetic analysis and clinical features were compared. Based on the immunohistochemistry, 26 (22 ACPs and four undetermined CPs) showed nuclear β-catenin expression, 11 (nine PCPs and two undetermined CPs) exhibited positive BRAF V600E immunostaining and one PCP showed membranous β-catenin expression and negative for BRAF V600E immunostaining. Among the 26 nuclear β-catenin expression cases, 11 had CTNNB1 mutations; however, 15 cases had mutations of neither CTNNB1 nor BRAF V600E. All 11 BRAF V600E immunopositive cases had BRAF V600E mutations. When comparing clinical features between, pediatric patients and those with tumor calcification and less solid components on MRI more commonly had nuclear β-catenin expression tumors than BRAF V600E immunopositive tumors, reflecting the differences in clinical features between ACP and PCP. Accordingly, immunohistochemistry can replace genetic analysis as an aid to determine the subtype diagnosis of CP in general medical practice.
Springer Science+Business Media|Springer Nature
This is a post-peer-review, pre-copyedit version of an article published in Endocrine Pathology. The final authenticated version is available online at: http://dx.doi.org/10.1007/s12022-020-09644-z.
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