鼻窦黏液瘤（SNM）是一种罕见的良性间叶组织肿瘤，在免疫组化中可通过核定位异常的β-连环蛋白显示其独特的临床病理学特征。其分子基础与粘液性纤维瘤的“黏液型变体”相关联。本文描述了8例SNM患者，并比较了与粘液性纤维瘤的临床和生物学差异。我们的病例队列包括5名男性和3名女性（年龄范围：10个月至12岁），其中6名年龄小于等于24个月。所有患者出现面部肿胀，反映涉及上颌骨的病变，并均行手术切除。所有肿瘤细胞均具有不同程度的细胞性，并以繁杂的黏液性背景下的无动力星状细胞为主，同时显示弥漫性核β-连环蛋白表达。所有SNM病例均通过Oncopanel测序进行分析。测序失败的3例中，2例成功病例的第3外显子CTNNB1发生突变，涉及泛素识别基序，另外3例患者显示腺瘤性息肉症相关的APC基因缺失。其中1例患者进行了阿记波里斯基因的生殖系遗传测试，结果为阴性。另外7例患者未进行生殖系遗传测试。我们对8个SNM患者进行了1个月至23年的随访观察。其中1例患者发生了局部复发，其余患者均未发现有病变。这与粘液性纤维瘤通常在切除后高复发率的情况形成对比。我们的研究结果扩大了伴有WNT/β-连环蛋白通路的肿瘤谱，并强调了与粘液性纤维瘤相比，SNM在组织学、临床和遗传学上的差异。APC基因缺失可能意味着潜在的生殖系遗传变异和家族性腺瘤性息肉症。Copyright © 2023 Wolters Kluwer Health，Inc. 保留所有权利。

Sinonasal myxoma (SNM) is a rare, benign mesenchymal neoplasm with distinct clinicopathologic features and aberrant nuclear localization of β-catenin by immunohistochemistry. The molecular underpinnings have been linked to that of a "myxoid variant" of desmoid fibromatosis. Herein, we describe a series of 8 cases of SNM and propose clinical and biologic differences compared with desmoid fibromatosis. Our patient cohort is comprised of 5 males and 3 females (age range: 10 mo to 12 y), 6 of whom are aged less than or equal to 24 months. All presented with facial swelling, reflecting lesions involving the maxillary bone, and all underwent resection. All tumors were variably cellular and comprised of bland spindled to stellate cells in a profusely myxoid background with diffuse nuclear β-catenin expression. All cases of SNM were analyzed by next-generation sequencing using the Oncopanel assay. Three cases failed sequencing, 2 of 5 successful cases exhibited exon 3 CTNNB1 alterations involving the ubiquitin recognition motif, and 3 had adenomatous polyposis coli (APC) deletions. One patient had APC germline testing which was negative. No germline testing was available for the remaining 7 patients. Follow-up data over a range of 1 month to 23 years was available for 7 of the 8 SNMs. One case patient had local recurrence, and all were alive without evidence of disease. This is in contrast to the high recurrence rate typically seen in desmoid fibromatosis, particularly after resection. Our findings expand the spectrum of tumors with underlying WNT/β-catenin pathway and highlight the histologic, clinical, and genetic differences of SNM compared with desmoid fibromatosis. APC deletion raises the possibility of underlying germline alteration and familial adenomatous polyposis.Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.