Immunohistochemical and genetic analysis of respiratory epithelial adenomatoid hamartomas and seromucinous hamartomas: are they precursor lesions to sinonasal low-grade tubulopapillary adenocarcinomas?
Abstract
Respiratory epithelial adenomatoid hamartoma (REAH) and seromucinous hamartoma (SH) are rare tumor-like lesions of the nasal cavity, paranasal sinuses. and nasopharynx. The pathogenesis of REAH/SH is still unclear.
Neoplastic proliferation, chronic mechanical irritation, inflammation. or possible embryological tissue misplacement are speculated as possible mechanisms of their development. Low-grade tubulopapillary adenocarcinoma (LGTA) is a rare variant of nonsalivary, nonintestinal type sinonasal adenocarcinoma.
The aim of this study was to evaluate the immunohistochemical and genetic profiles of 10 cases of REAH/SH, with serous, mucinous, and respiratory components evaluated separately and to compare these findings with the features of 9 cases of LGTA. All cases of REAH/SH and LGTA were analyzed immunohistochemically with a cocktail of mucin antigens (MUC1, MUC2.
MUC4, MUC5AC, MUC6) and with epithelial (CK7, CK20. CDX2, SATB2) and myoepithelial markets (S100 protein, p63, SOX10).
The next-generation sequencing assay was performed using FusionPlex Solid Tumor Kit (ArcherDx) in 10 cases of REAH/SH, and the EGFR-ZNF267 gene fusion was detected in 1 of them. Two female REAH/SH cases were assessed for the presence of clonality.
Using the human androgen receptor assay, 1 case was proved to be clonal. The serous component of REAH/SH was positive for CK7/MUC1 and SOX10 similarly to LGTA.
Although REAH/SH and LGTA are histopathologically and clinically separate entities, the overlap in their morphological and immuno- histochemical profiles suggests that REAH/SH might be a precursor lesion of LGTA. (C) 2019 Elsevier Inc. All rights reserved.