TY - JOUR
T1 - Biphenotypic Branchioma
T2 - A Better Name Than Ectopic Hamartomatous Thymoma for a Neoplasm with HRAS Mutation
AU - Thompson, Lester D.R.
AU - Gagan, Jeffrey
AU - Washington, Antoine
AU - Miller, Rodney T.
AU - Bishop, Justin A.
N1 - Publisher Copyright:
© 2020, This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.
PY - 2020/12
Y1 - 2020/12
N2 - Ectopic hamartomatous thymoma is a rare neck lesion originally thought to represent a non-neoplastic hamartoma, even though thymic origin has been questioned, and there is uncertainty about whether the lesion is a neoplasm. We investigated the genetics by performing targeted next generation sequencing (NGS). Three cases were identified from the authors’ consultation files. A custom, targeted NGS panel including 1385 pan-cancer‐related genes was performed on all cases. Three patients included 2 males and 1 female, aged 50, 58 and 70 years, respectively (mean 59.3 years), with tumors arising in the low anterior neck. All cases showed classical histologic features of EHT, with one case showing intraductal carcinoma in association with the EHT. By targeted NGS, one case harbored a hotspot HRAS mutation (p.Gln61Lys), while the other two cases only showed non oncogenic variants. Dual mesoderm and endoderm derivation/differentiation (biphenotypic) has been previously recognized, with epithelial and myoepithelial components, and arising from the apparatus contributing to neck development (branchial apparatus). Thus, EHT has been shown to have genetic alterations in HRAS. These findings, without evidence of thymic derivation or an ectopic tissue location, strongly support that EHT is a true neoplasm. The name biphenotyic branchioma more correctly reflects the true nature of this dual mesoderm and endoderm derived tumor occurring in the lower neck.
AB - Ectopic hamartomatous thymoma is a rare neck lesion originally thought to represent a non-neoplastic hamartoma, even though thymic origin has been questioned, and there is uncertainty about whether the lesion is a neoplasm. We investigated the genetics by performing targeted next generation sequencing (NGS). Three cases were identified from the authors’ consultation files. A custom, targeted NGS panel including 1385 pan-cancer‐related genes was performed on all cases. Three patients included 2 males and 1 female, aged 50, 58 and 70 years, respectively (mean 59.3 years), with tumors arising in the low anterior neck. All cases showed classical histologic features of EHT, with one case showing intraductal carcinoma in association with the EHT. By targeted NGS, one case harbored a hotspot HRAS mutation (p.Gln61Lys), while the other two cases only showed non oncogenic variants. Dual mesoderm and endoderm derivation/differentiation (biphenotypic) has been previously recognized, with epithelial and myoepithelial components, and arising from the apparatus contributing to neck development (branchial apparatus). Thus, EHT has been shown to have genetic alterations in HRAS. These findings, without evidence of thymic derivation or an ectopic tissue location, strongly support that EHT is a true neoplasm. The name biphenotyic branchioma more correctly reflects the true nature of this dual mesoderm and endoderm derived tumor occurring in the lower neck.
KW - Biphenotypic branchioma
KW - Branchial pouch
KW - Carcinoma
KW - Ectopic hamartomatous thymoma
KW - NGS
KW - Neoplasm
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U2 - 10.1007/s12105-020-01132-4
DO - 10.1007/s12105-020-01132-4
M3 - Article
C2 - 32026292
AN - SCOPUS:85079165874
SN - 1936-055X
VL - 14
SP - 884
EP - 888
JO - Head and Neck Pathology
JF - Head and Neck Pathology
IS - 4
ER -