Simon Andreasen1,2, Linea Cecilie Melchior3, Katalin Kiss3, Justin Avery Bishop4, Estrid Høgdall5, Morten Grauslund3, Irene Wessel2, Preben Homøe1, Tina Klitmøller Agander3. 1. Department of Otorhinolaryngology and Maxillofacial Surgery, Zealand University Hospital, Koge, Denmark. 2. Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark. 3. Department of Pathology, Copenhagen University Hospital, Copenhagen, Denmark. 4. Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas. 5. Department of Pathology, Herlev Hospital, University of Copenhagen, Herlev, Denmark.
Abstract
BACKGROUND: Polymorphous adenocarcinoma (PAC) of the palatal minor salivary glands, previously known as polymorphous low-grade adenocarcinoma, is the second most common intraoral malignant salivary gland carcinoma after adenoid cystic carcinoma (ACC) and carries an excellent prognosis. Unfortunately, PAC demonstrates cytological overlap with 2 other salivary gland tumors frequently encountered in the same location, namely ACC and pleomorphic adenoma (PA). Recently, the protein kinase D1 (PRKD1) hotspot mutation E710D was demonstrated to be specific for PAC and to be present in the majority of cases. The objective of the current study was to investigate the value of PRKD1 hotspot sequencing in identifying PAC in paired fine-needle aspiration (FNA) and surgical specimens from cases of PAC, ACC, and PA. METHODS: Paired May-Grunwald-Giemsa-stained FNA and corresponding surgical specimens were collected from 18 PAC cases, 25 ACC cases, and 21 PA cases. Both sets of specimens were subjected to dideoxynucleotide sequencing of PRKD1 exon 15, including the PRKD1 E710D hotspot. RESULTS: Of the PAC cases, approximately 50% demonstrated identical PRKD1 E710D hotspot mutations on the FNA specimen and corresponding surgical specimen. Two ACC specimens had point mutations within the sequenced region in the FNA specimen as well as the surgical specimen, but none were located in the hotspot region. None of the PA cases demonstrated PRKD1 mutations. The specificity of the PRKD1 hotspot mutation for identifying PAC among ACC and PA cases was 100% whereas the sensitivity was 50%. CONCLUSIONS: The PRKD1 E710D hotspot mutation is highly specific for identifying PAC on FNA among cases of ACC and PA, whereas the sensitivity is only modest. Alternative PRKD1 mutations exclude PAC, and are more suggestive of ACC. Cancer Cytopathol 2018;126:275-81.
BACKGROUND: Polymorphous adenocarcinoma (PAC) of the palatal minor salivary glands, previously known as polymorphous low-grade adenocarcinoma, is the second most common intraoral malignant salivary gland carcinoma after adenoid cystic carcinoma (ACC) and carries an excellent prognosis. Unfortunately, PAC demonstrates cytological overlap with 2 other salivary gland tumors frequently encountered in the same location, namely ACC and pleomorphic adenoma (PA). Recently, the protein kinase D1 (PRKD1) hotspot mutation E710D was demonstrated to be specific for PAC and to be present in the majority of cases. The objective of the current study was to investigate the value of PRKD1 hotspot sequencing in identifying PAC in paired fine-needle aspiration (FNA) and surgical specimens from cases of PAC, ACC, and PA. METHODS: Paired May-Grunwald-Giemsa-stained FNA and corresponding surgical specimens were collected from 18 PAC cases, 25 ACC cases, and 21 PA cases. Both sets of specimens were subjected to dideoxynucleotide sequencing of PRKD1 exon 15, including the PRKD1E710D hotspot. RESULTS: Of the PAC cases, approximately 50% demonstrated identical PRKD1E710D hotspot mutations on the FNA specimen and corresponding surgical specimen. Two ACC specimens had point mutations within the sequenced region in the FNA specimen as well as the surgical specimen, but none were located in the hotspot region. None of the PA cases demonstrated PRKD1 mutations. The specificity of the PRKD1 hotspot mutation for identifying PAC among ACC and PA cases was 100% whereas the sensitivity was 50%. CONCLUSIONS: The PRKD1E710D hotspot mutation is highly specific for identifying PAC on FNA among cases of ACC and PA, whereas the sensitivity is only modest. Alternative PRKD1 mutations exclude PAC, and are more suggestive of ACC. Cancer Cytopathol 2018;126:275-81.
Authors: Bin Xu; Ronald Ghossein; Alan Ho; Kartik Viswanathan; Anjanie Khimraj; Maelle Saliba; Jennifer R Cracchiolo; Nora Katabi Journal: Head Neck Date: 2021-04-24 Impact factor: 3.821