Papillary thyroid carcinoma with nodular fasciitis-like stroma and β-catenin mutations should be renamed papillary thyroid carcinoma with desmoid-type fibromatosis.

One of these rare and poorly characterized variants is papillary thyroid carcinoma with nodular fasciitis-like stroma, of which fewer than 30 cases have been documented, mostly as isolated reports. It is a dual tumor comprising a malignant epithelial proliferation that harbors typical features of conventional papillary thyroid carcinoma, admixed with a prominent mesenchymal proliferation resembling nodular fasciitis or fibromatosis. Thus, the terms papillary thyroid carcinoma with nodular fasciitis-like stroma and papillary thyroid carcinoma with fibromatosis-like stroma are used interchangeably; however, the former term suggests a self-limited and regressing disease, whereas the latter one suggests a recurrent and potentially aggressive one. Better genetic and ultrastructural characterization could lead to more appropriate terminology and management. We therefore propose that in cases of papillary thyroid carcinoma with a prominent mesenchymal component, mutations in CTNNB1 should be sought; when they are present, the term ‘papillary thyroid carcinoma with desmoid-type fibromatosis’ should be used.Â

We found that genetic ablation or overexpression of S100a4 in both Apc- and Smad4-mutant mice do not affect tumour initiation in the intestinal tract. In contrast, S100a4 epithelial overexpression in Apc1638N/+/KRASV12G mice increases the dissemination of intestinal tumour cells to the liver, in agreement with its role in tumour metastasis. Moreover, we report a novel role for S100a4 in desmoidformation where S100a4 deficiency results in a significant reduction of the tumour burden characteristic of the Apc1638N model. In agreement with these results, S100a4 appears to be co-expressed together with mesenchymal stem cell (MSC) markers in desmoid tumours from Apc1638N/+ mice, as well as from sporadic and hereditary human desmoids.

This report describes the case of a 32-month-old girl with DF of the head and neck. The tumor was resected with gross residual tumors. Recurrence occurred 3Â months later and then the patient was treated with iodine-125 interstitial brachytherapy. The tumor was completely absent 6Â months after brachytherapy. No recurrence was found 60Â months after brachytherapy during follow-up. No severe toxicities or growth abnormalities were observed. Very-low-dose rate brachytherapy as the sole modality could be a reasonable alternative for the treatment of inoperable DF of the head and neck, which avoids the risk of cosmetic deformity caused by surgery, especially in pediatric patients. In addition, long-term follow-up is recommended.

Desmoid tumors of the abdominal wall have a favorable prognosis after surgical resection, which remains a safe and effective treatment. Wild-type tumors are common, whereas the incidence of S45F mutation in the beta-catenin gene is lower than in other anatomic sites. Upfront surgery may be considered in selected women who wish to bear a child.

This case report presents an incidentally detected DF of the tibia, which was diagnosed using a minimally invasive approach. The aim of this study was to discuss the clinical, histological, immunohistochemical and radiographic characteristics of this rare neoplasm, with a focus on image-guided bone biopsy.

Imaging criteria for measuring the response of desmoid fibromatosis to systemic therapy are not well established. We evaluated a series of patients with desmoids who underwent systemic therapy to document magnetic resonance imaging (MRI) features associated with a positive clinical response.