Sinonasal Myxoma : A Distinct Entity or a Myxoid Variant of Desmoid Fibromatosis?

Copyright © 2023 United States & Canadian Academy of Pathology. Published by Elsevier Inc. All rights reserved..

Sinonasal myxoma (SNM) is a rare benign mesenchymal tumor that arises in the sinonasal cavity or maxilla and almost exclusively affects young children. Currently, it is considered a specific entity, but its molecular characteristics have not been reported. Lesions diagnosed as SNM and odontogenic myxoma/fibromyxoma were identified from the participating institutions, and the clinicopathologic features were recorded. Immunohistochemistry for β-catenin was performed in all cases with available tissue. Next-generation sequencing was performed in all cases with SNM. Five patients with SNM were identified, including 3 boys and 2 girls with an age range of 20-36 months (mean: 26 months). The tumors were well defined, centered in the maxillary sinus, surrounded by a rim of woven bone, and composed of a moderately cellular proliferation of spindle cells oriented in intersecting fascicles in a variably myxocollagenous stroma that contained extravasated erythrocytes. Histologically, the tumors resembled myxoid desmoid fibromatosis. Three tested cases showed nuclear expression of β-catenin. In 3 tumors, next-generation sequencing revealed intragenic deletions of APC exons 5-6, 9 and 15, or 16, respectively, with concurrent loss of the other wild-type copy of APC predicted to result in biallelic inactivation. The deletions were identical to those that occur in desmoid fibromatosis, and copy number analysis raised the possibility that they were germline. In addition, 1 case showed the possible deletion of APC exons 12-14, and another case exhibited a CTNNB1 p. S33C mutation. Ten patients with odontogenic myxoma/fibromyxoma were identified, including 4 women and 6 men (mean age: 42 years). Seven tumors involved the mandible and 3 the maxilla. Histologically, the tumors differed from SNM, and all cases lacked nuclear expression of β-catenin. These findings suggest that SNM represents a myxoid variant of desmoid fibromatosis that often arises in the maxilla. The APC alterations might be germline, and therefore, genetic testing of the affected patients should be considered.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:36

Enthalten in:

Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc - 36(2023), 7 vom: 13. Juli, Seite 100189

Sprache:

Englisch

Beteiligte Personen:

Velez Torres, Jaylou M [VerfasserIn]
Mata, Douglas A [VerfasserIn]
Briski, Laurence M [VerfasserIn]
Green, Donald C [VerfasserIn]
Cloutier, Jeffrey M [VerfasserIn]
Kerr, Darcy A [VerfasserIn]
Montgomery, Elizabeth A [VerfasserIn]
Rosenberg, Andrew E [VerfasserIn]

Links:

Volltext

Themen:

β-catenin
APC
Beta Catenin
Desmoid fibromatosis
Infant
Journal Article
Myxoma
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Sinonasal
Young children

Anmerkungen:

Date Completed 24.07.2023

Date Revised 26.07.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.modpat.2023.100189

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM355633795