Biphasic Thyroid-Like Low-Grade Nasopharyngeal Papillary Adenocarcinoma with a Prominent Spindle Cell Component: A Case Report

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TLLG-NPPA) is a distinctly rare malignancy of the nasopharynx. Morphologically and immunophenotypically, TLLG-NPPA resembles papillary thyroid carcinoma (PTC) and is characterized by a papillary architecture with PTC-like nuclear featur...

Full description

Bibliographic Details
Main Authors: Sang Hwa Lee, Hyunjin Kim, Min Ju Kim, Byungwha Kim, Hyun-Soo Kim
Format: Article
Language:English
Published: MDPI AG 2020-05-01
Series:Diagnostics
Subjects:
Online Access:https://www.mdpi.com/2075-4418/10/5/323
_version_ 1797567506750111744
author Sang Hwa Lee
Hyunjin Kim
Min Ju Kim
Byungwha Kim
Hyun-Soo Kim
author_facet Sang Hwa Lee
Hyunjin Kim
Min Ju Kim
Byungwha Kim
Hyun-Soo Kim
author_sort Sang Hwa Lee
collection DOAJ
description Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TLLG-NPPA) is a distinctly rare malignancy of the nasopharynx. Morphologically and immunophenotypically, TLLG-NPPA resembles papillary thyroid carcinoma (PTC) and is characterized by a papillary architecture with PTC-like nuclear features and thyroid transcription factor-1 expression. Recently, some cases of TLLG-NPPA with a spindle cell component have been reported. In this study, we report a very interesting case of biphasic TLLG-NPPA that was predominantly composed of spindle cells, with comprehensive analyses of its clinical, pathological, and immunophenotypical features. A 50-year-old woman presented with a sensation of a foreign body in the nasopharynx. Nasopharyngoscopy and computed tomography demonstrated a pedunculated mass arising from the nasopharyngeal roof. Based on the clinical impression of a nasopharyngeal tumor, an excisional biopsy was performed. At low-power magnification, the nasopharyngeal mass consisted of papillary tumor tissue, the growth pattern and architecture of which resembled those of PTC. The papillae were complex and packed tightly with fibrovascular cores. At high-power magnification, each papillary structure was lined with a pseudostratified cuboidal-to-columnar epithelium. The tumor cell nuclei frequently showed a ground-glass appearance, intranuclear grooves, pseudoinclusions, and membrane thickening and irregularity, resembling the characteristic nuclear morphology of PTC. These histological features were compatible with TLLG-NPPA. Intriguingly, in between the papillary components were spindle cells that appeared very similar to the glandular epithelial cells that imperceptibly merged with the papillary component. This spindle cell component comprised two-thirds of the entire tumor volume. The nuclear morphology of the spindle cell component was similar to that of the papillary component. On immunostaining, both the papillary and spindle cell components were diffusely and strongly positive for thyroid transcription factor-1, cytokeratin 7, cytokeratin 19, vimentin, and Hector Battifora mesothelial-1. In contrast, the tumor cells tested negative for p63, p40, smooth muscle actin, S-100, cytokeratin 5/6, thyroglobulin, BRAF V600E, and Epstein–Barr virus-encoded small RNAs. Only two cases of biphasic TLLG-NPPA exhibiting a prominent spindle cell component had been reported previously in the English literature. When the pathologist receives a primary nasopharyngeal mass with the aforementioned histological features, particularly biopsy specimens with predominant spindle cells, biphasic TLLG-NPPA should be considered in the differential diagnosis. By describing its detailed clinicopathological characteristics, we anticipate that this report will expand the existing knowledge on the spindle cell component associated with TLLG-NPPA.
first_indexed 2024-03-10T19:43:58Z
format Article
id doaj.art-95e6210187be457bb3081e02f26aac63
institution Directory Open Access Journal
issn 2075-4418
language English
last_indexed 2024-03-10T19:43:58Z
publishDate 2020-05-01
publisher MDPI AG
record_format Article
series Diagnostics
spelling doaj.art-95e6210187be457bb3081e02f26aac632023-11-20T01:00:42ZengMDPI AGDiagnostics2075-44182020-05-0110532310.3390/diagnostics10050323Biphasic Thyroid-Like Low-Grade Nasopharyngeal Papillary Adenocarcinoma with a Prominent Spindle Cell Component: A Case ReportSang Hwa Lee0Hyunjin Kim1Min Ju Kim2Byungwha Kim3Hyun-Soo Kim4Pathology Center, Seegene Medical Foundation, Seoul 04805, KoreaDepartment of Pathology and Translational Genomics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, KoreaDepartment of Pathology, Soonchunhyang University College of Medicine, Bucheon Hospital, Bucheon 14584, KoreaLuke Ear, Nose, and Throat Clinic, Donghae 25769, KoreaDepartment of Pathology and Translational Genomics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, KoreaThyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TLLG-NPPA) is a distinctly rare malignancy of the nasopharynx. Morphologically and immunophenotypically, TLLG-NPPA resembles papillary thyroid carcinoma (PTC) and is characterized by a papillary architecture with PTC-like nuclear features and thyroid transcription factor-1 expression. Recently, some cases of TLLG-NPPA with a spindle cell component have been reported. In this study, we report a very interesting case of biphasic TLLG-NPPA that was predominantly composed of spindle cells, with comprehensive analyses of its clinical, pathological, and immunophenotypical features. A 50-year-old woman presented with a sensation of a foreign body in the nasopharynx. Nasopharyngoscopy and computed tomography demonstrated a pedunculated mass arising from the nasopharyngeal roof. Based on the clinical impression of a nasopharyngeal tumor, an excisional biopsy was performed. At low-power magnification, the nasopharyngeal mass consisted of papillary tumor tissue, the growth pattern and architecture of which resembled those of PTC. The papillae were complex and packed tightly with fibrovascular cores. At high-power magnification, each papillary structure was lined with a pseudostratified cuboidal-to-columnar epithelium. The tumor cell nuclei frequently showed a ground-glass appearance, intranuclear grooves, pseudoinclusions, and membrane thickening and irregularity, resembling the characteristic nuclear morphology of PTC. These histological features were compatible with TLLG-NPPA. Intriguingly, in between the papillary components were spindle cells that appeared very similar to the glandular epithelial cells that imperceptibly merged with the papillary component. This spindle cell component comprised two-thirds of the entire tumor volume. The nuclear morphology of the spindle cell component was similar to that of the papillary component. On immunostaining, both the papillary and spindle cell components were diffusely and strongly positive for thyroid transcription factor-1, cytokeratin 7, cytokeratin 19, vimentin, and Hector Battifora mesothelial-1. In contrast, the tumor cells tested negative for p63, p40, smooth muscle actin, S-100, cytokeratin 5/6, thyroglobulin, BRAF V600E, and Epstein–Barr virus-encoded small RNAs. Only two cases of biphasic TLLG-NPPA exhibiting a prominent spindle cell component had been reported previously in the English literature. When the pathologist receives a primary nasopharyngeal mass with the aforementioned histological features, particularly biopsy specimens with predominant spindle cells, biphasic TLLG-NPPA should be considered in the differential diagnosis. By describing its detailed clinicopathological characteristics, we anticipate that this report will expand the existing knowledge on the spindle cell component associated with TLLG-NPPA.https://www.mdpi.com/2075-4418/10/5/323nasopharynxthyroid-like low-grade nasopharyngeal papillary adenocarcinomaprominent spindle cell componentimmunohistochemistrythyroid transcription factor-1
spellingShingle Sang Hwa Lee
Hyunjin Kim
Min Ju Kim
Byungwha Kim
Hyun-Soo Kim
Biphasic Thyroid-Like Low-Grade Nasopharyngeal Papillary Adenocarcinoma with a Prominent Spindle Cell Component: A Case Report
Diagnostics
nasopharynx
thyroid-like low-grade nasopharyngeal papillary adenocarcinoma
prominent spindle cell component
immunohistochemistry
thyroid transcription factor-1
title Biphasic Thyroid-Like Low-Grade Nasopharyngeal Papillary Adenocarcinoma with a Prominent Spindle Cell Component: A Case Report
title_full Biphasic Thyroid-Like Low-Grade Nasopharyngeal Papillary Adenocarcinoma with a Prominent Spindle Cell Component: A Case Report
title_fullStr Biphasic Thyroid-Like Low-Grade Nasopharyngeal Papillary Adenocarcinoma with a Prominent Spindle Cell Component: A Case Report
title_full_unstemmed Biphasic Thyroid-Like Low-Grade Nasopharyngeal Papillary Adenocarcinoma with a Prominent Spindle Cell Component: A Case Report
title_short Biphasic Thyroid-Like Low-Grade Nasopharyngeal Papillary Adenocarcinoma with a Prominent Spindle Cell Component: A Case Report
title_sort biphasic thyroid like low grade nasopharyngeal papillary adenocarcinoma with a prominent spindle cell component a case report
topic nasopharynx
thyroid-like low-grade nasopharyngeal papillary adenocarcinoma
prominent spindle cell component
immunohistochemistry
thyroid transcription factor-1
url https://www.mdpi.com/2075-4418/10/5/323
work_keys_str_mv AT sanghwalee biphasicthyroidlikelowgradenasopharyngealpapillaryadenocarcinomawithaprominentspindlecellcomponentacasereport
AT hyunjinkim biphasicthyroidlikelowgradenasopharyngealpapillaryadenocarcinomawithaprominentspindlecellcomponentacasereport
AT minjukim biphasicthyroidlikelowgradenasopharyngealpapillaryadenocarcinomawithaprominentspindlecellcomponentacasereport
AT byungwhakim biphasicthyroidlikelowgradenasopharyngealpapillaryadenocarcinomawithaprominentspindlecellcomponentacasereport
AT hyunsookim biphasicthyroidlikelowgradenasopharyngealpapillaryadenocarcinomawithaprominentspindlecellcomponentacasereport