We report a case of a patient with a de novo germline heterozygous truncating variant of CTNNB1 gene (c.2172del, p.Tyr724Ter) causing neurodevelopmental disorder with spastic diplegia and visual defects syndrome (NEDSDV) associated with a new clinical feature - severe pediatric-onset osteoporosis and multiple fractures. A functional effect of the identified variant was demonstrated using adipose-tissue derived primary mesenchymal stem cells, where we detected the alteration of CTNNB1mRNA and β-catenin protein levels using real-time PCR and Western blot analysis.

Recently, the loss-of-function, heterozygous, and de novo mutations of the CTNNB1 gene have been proven to be partially responsible for intellectual disability in some patients. Herein, we report two unrelated children with neurodevelopmental disorder, abnormal facial features, speech impairments, microcephaly, and dystonia. Based on whole exome sequencing (WES), two new heterozygous and pathogenic mutations in exon 10 (c.1586dupA:p.Q530Afs*42) and exon 4 (c.257dup:p.Y86*) were identified in the CTNNB1 gene for the first time. These findings not only enrich the genetic spectrum of the CTNNB1 gene but also provide evidence for its role in neuronal development.

Nine cases of mesenteric desmoid-type fibromatosis were diagnosed and treated in Taizhou Hospital, Wenzhou Medical University between January 2010 and May 2022, including 2 females and 7 males, aged 16 to 59 years. The lesions were in the mesentery of small intestine with 7 cases, ileocecal junction with 1 cases and transverse colon with 1 case. The tumors had an unclear boundary and no envelope, the section was solid, gray and tough. The mean maximum diameter was (10.7±8.5) cm (range 3.5-33.0 cm). Microscopically, fusiform fibroblasts and myofibroblasts were parallel, bunched or staggered, buried in a large amount of extracellular collagen. The cell morphology was relatively consistent, without obvious atypia, and mitosis was rare. Immunohistochemistry showed that the tumor cells were positive for vimentin (9/9), β-catenin (9/9), while smooth muscle actin (5/9) stains were focally positive. Ki-67 proliferation index was 1%-10%. Cytokeratin Pan, S-100, STAT6, CD117, DOG1, CD34, desmin and anaplastic lymphoma kinase stains were negative. Genetic analysis showed that there were 7 cases of c.121G>A(p.Thr41Ala) mutation of CTNNB1 gene, 1 case of c.121G>A(p.Thr41Ala) and 1 case of c.134C>T(p.Ser45Phe) double mutation, and 1 case of wild type. Tumors were surgically resected in all 9 cases. Eight cases had no recurrence or metastasis, 1 case had recurrence 6 months later, and no recurrence or metastasis after additional surgical resection.
9例肠系膜韧带样纤维瘤病患者于2010年1月至2022年5月就诊于温州医科大学附属台州医院，其中男性7例，女性2例，年龄16~59岁；肿瘤位于小肠系膜7例，回盲部系膜1例，横结肠系膜1例；肿瘤最大径3.5~33.0 cm，平均（10.7±8.5）cm，无包膜，界不清，部分病例侵犯肠肌壁组织，切面呈实性，灰白色，质韧。组织病理学检查见梭形的纤维母细胞及肌纤维母细胞平行状、束状或交错排列，埋于大量细胞外胶原内，细胞形态较一致，无明显异型性，核分裂象少见。免疫组织化学检测结果显示，9例患者的肿瘤细胞波形蛋白、β联蛋白均阳性，5例患者α-平滑肌肌动蛋白阳性，Ki-67阳性指数为1%~10%，广谱细胞角蛋白、S-100蛋白、信号转导及转录激活蛋白6、CD117、DOG1、CD34、结蛋白和间变性淋巴瘤激酶均阴性。7例存在CTNNB1基因c.121G>A（p.Thr41Ala）突变，1例c.121G>A（p.Thr41Ala）和c.134C>T（p.Ser45Phe）双突变，1例为野生型。9例患者均接受手术切除，8例无复发及转移；1例半年后复发，再次手术切除后无复发及转移。.

Neurodevelopmental disorder with spastic diplegia and visual defects (NEDSDV) is a rare autosomal dominant genetic disorder caused by genetic alterations in the CTNNB1 gene. CTNNB1 is a gene that encodes β-catenin, an effector protein in the canonical Wnt pathway involved in stem cell differentiation and proliferation, synaptogenesis, and a wide range of essential cellular mechanisms. Mutations in this gene are also found in specific malignancies as well as exudative vitreoretinopathy. To date, only a limited number of cases of this disease have been reported, and though they share some phenotypic manifestations such as intellectual disability, developmental delay, microcephaly, behavioral abnormalities, and dystonia, the variety of phenotypic traits of these patients shows extreme heterogeneity. In this study, two cases of NEDSDV with de novo CTNNB1 mutations: c.1420C>T(p.R474X) and c.1377_1378Del(p.Ala460Serfs*29), found with whole exome sequencing (WES) have been reported and the clinical and paraclinical characteristics of these patients have been described. Due to such a wide range of clinical characteristics, the identification of new patients and novel variants is of great importance in order to establish a more complete phenotypic spectrum, as well as to conclude the genotype-phenotype correlations in these cases.

Intercalated duct lesions (IDLs) are usually asymptomatic. We report a case of IDL, in which a palpable mass formed. The patient was a 45-year-old Japanese male, who noticed a mass in the left parotid region. The nodular lesion was well-circumscribed, but did not have a fibrous capsule or exhibit infiltrative growth. It contained a small cystic space and consisted of basaloid cells arranged in a cribriform pattern and inner ductal cells. It had some solid areas of nest-like proliferation displaying mild cellular atypia. Immunohistochemically, the luminal cells were positive for cytokeratin (CK)7 and epithelial membrane antigen, and the abluminal cells were positive for CK5/6, p63, and DOG1. S-100 protein-positive stromal cells were also seen. The lesion\'s cells were all positive for SOX10, and the nuclei of some basaloid cells were positive for β-catenin. The Ki-67 labeling index was 3.8%. The ductal cells contained diastase-digestion-resistant, Periodic acid Schiff-positive zymogen granules. Genetically, the lesion harbored a missense mutation in the CTNNB1 gene. We diagnosed the lesion as an IDL. As IDLs are usually small non-neoplastic lesions, symptomatic cases are rare. Based on its common immunohistochemical and genetic features, IDL may be a precursor of basal cell adenoma/adenocarcinoma, such as intercalated duct adenoma.

Teratocarcinosarcoma is an extremely rare malignancy of the nasal cavity and paranasal sinuses. It exhibits both sarcomatous and carcinomatous components. Less than 100 cases are reported. It presents in adults with only two reported cases in infancy. Here we present a case of 3-week-old female with antenatally detected ocular mass. MRI revealed an exophytic right ocular mass (10 × 7.0 × 7.0 cm) with intracranial extension. The tumor consisted of malignant glands and mesenchymal elements of undifferentiated blastema-like cells and immature neuroepithelium. After an initial diagnosis and treatment for a Wilms tumor protocol, the mass showed no response. A second opinion rendered a diagnosis of sinonasal teratocarcinosarcoma. The patient underwent surgical resection and seven cycles of CNS ICE chemotherapy. A second debulking surgery revealed a very scant viable tumor with post-treatment changes. The patient is alive at 43 months on weekly vincristine maintenance. Molecular testing revealed a somatic CTNNB1 gene mutation. In conclusion, this is a rare and aggressive tumor which showed disease free survival beyond that reported in the literature with the appropriate use of multimodality therapy.

Aggressive fibromatosis (AF) is usually considered a benign tumor. Reports of the association between AF and malignancies have appeared infrequently. Herein, we report two cases of AF arising in the neck that were associated with papillary thyroid cancer. Two cases are presented in this article. One is a 31-year-old male patient who was diagnosed with AF 9 months after his thyroid cancer operation; there has been no recurrence after surgical resection and postoperative radiotherapy. The other is a 53-year-old female patient who was diagnosed with thyroid cancer and AF simultaneously. There is still no recurrence after surgical resection, endocrine therapy and thyroid-stimulating hormone (TSH) suppression treatment. Both cases showed β-catenin positivity upon further immunohistochemistry (IHC) examination. AF is a rare and benign tumor. It can occur in association with malignancies, such as thyroid cancer. Whether a patient diagnosed with AF associated with thyroid cancer has a family history of a familial adenomatous polyposis (FAP) mutation or β-catenin mutation should be given more attention. The treatment strategy in this situation includes surgical excision combination with radiotherapy and endocrine therapy to reduce the recurrence rate.

CTNNB1 encodes for the β-catenin protein, a component of the cadherin adhesion complex, which regulates cell-cell adhesion and gene expression in the canonical Wnt signaling pathway. Mutations in CTNNB1 have been reported to be associated with cancer and mental disorders. Recently, loss-of-function mutations in CTNNB1 have been observed in patients with intellectual disability and some other clinical manifestations including motor and language delays, microcephaly, and mild visual defects. We report an 8-year-old Iranian girl with intellectual disability, hypotonia, impaired vision such as vitreomacular adhesion, motor delay, and speech delay. A novel, de novo nonsense mutation (c.1014G > A; p.Trp338Ter) in exon 7 of the CTNNB1 (NM_001904) gene was detected and confirmed by whole-exome sequencing and Sanger sequencing, respectively. This study helps to expand the growing list of loss-of-function mutations known in the CTNNB1 gene.

The most cases of persistence hyperplastic primary vitreous (PHPV) are unilateral and sporadic, however, bilateral presentation could be present in a small number of patients, in whom other genetic diseases must be ruled out. We describe a case of a 2 months child with bilateral persistence hyperplastic primary vitreous confirmed by ultrasound. In addition, with neurodevelopmental defects, microcephaly, facial dimorphism, axial hypotonia, and without brain abnormalities on MRI, in whom a de novo mutation of the CTNNB1 gene was found during the genetic study, which explains the findings.

The most cases of persistence hyperplastic primary vítreous (PHPV) are unilateral and sporadic, however, bilateral presentation could be present in a small number of patients, in whom other genetic diseases must be ruled out. We describe a case of a 2 months child with bilateral persistence hyperplastic primary vítreous confirmed by ultrasound. In addition, with neurodevelopmental defects, microcephaly, facial dimorphism, axial hypotonia, and without brain abnormalities on MRI, in whom a de novo mutation of the CTNNB1 gene was found during the genetic study, which explains the findings.