Background: Osteofibrous dysplasia-like adamantinoma (OFD-AD) and classic adamantinoma (AD) are rare, neoplastic diseases with only limited data supporting current treatment protocols. We believe that our retrospective multicenter cohort study is the largest analysis of patients with adamantinoma to date. The primary purpose of this study was to describe the disease characteristics and evaluate the oncological outcomes. The secondary purpose was to identify risk factors for local recurrence after surgical treatment and propose treatment guidelines. Methods: Three hundred and eighteen confirmed cases of OFD-AD and AD for which primary treatment was carried out between 1985 and 2015 were submitted by 22 tertiary bone tumor centers. Proposed clinical risk factors for local recurrence such as size, type, and margins were analyzed using univariable and multivariate Cox regression analysis. Results: Of the 318 cases, 128 were OFD-AD and 190 were AD. The mean age at diagnosis was 17 years (median, 14.5 years) for OFD-AD and 32 years (median, 28 years) for AD; 53% of the patients were female. The mean tumor size in the OFD-AD and AD groups combined was 7.8 cm, measured histologically. Sixteen percent of the patients sustained a pathological fracture prior to treatment. Local recurrence was recorded in 22% of the OFD-AD cases and 24% of the AD cases. None of the recurrences in the OFD-AD group progressed to AD. Metastatic disease was found in 18% of the AD cases and fatal disease, in 11% of the AD cases. No metastatic or fatal disease was reported in the OFD-AD group. Multivariate Cox regression analysis demonstrated that uncontaminated resection margins (hazard ratio [HR] = 0.164, 95% confidence interval [CI] = 0.092 to 0.290, p < 0.001), pathological fracture (HR = 1.968, 95% CI = 1.076 to 3.600, p = 0.028), and sex (female versus male: HR = 0.535, 95% CI = 0.300 to 0.952, p = 0.033) impacted the risk of local recurrence. Conclusions: OFD-AD and AD are parts of a disease spectrum but should be regarded as different entities. Our results support reclassification of OFD-AD into the intermediate locally aggressive category, based on the local recurrence rate of 22% and absence of metastases. In our study, metastatic disease was restricted to the AD group (an 18% rate). We advocate wide resection with uncontaminated margins including bone and involved periosteum for both OFD-AD and AD. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Preoperative radiotherapy increases the risk of postoperative wound complication in the treatment of soft tissue sarcoma (STS). This study aims to develop a nomogram for predicting major wound complication (MaWC) after surgery. Using the Oxford University Hospital (OUH) database, a total of 126 STS patients treated with preoperative radiotherapy and surgical resection between 2007 and 2021 were retrospectively reviewed. MaWC was defined as a wound complication that required secondary surgical intervention. Univariate and multivariate regression analyses on the association between MaWC and risk factors were performed. A nomogram was formulated and the areas under the Receiver Operating Characteristic Curves (AUC) were adopted to measure the predictive value of MaWC. A decision curve analysis (DCA) determined the model with the best discriminative ability. The incidence of MaWC was 19%. Age, tumour size, diabetes mellitus and metastasis at presentation were associated with MaWC in the univariate analysis. Age, tumour size, and metastasis at presentation were independent risk factors in the multivariate analysis. The sensitivity and specificity of the predictive model is 0.90 and 0.76, respectively. The AUC value was 0.86. The nomogram constructed in the study effectively predicts the risk of MaWC after preoperative radiotherapy and surgery for STS patients.

Background/Objectives: Extremity leiomyosarcoma is an uncommon soft tissue sarcoma with a more favorable prognosis than other anatomical subtypes. Risk stratification currently rests on tumor grade, size, and metastatic status. Vascular invasion is an established predictor of metastasis in mixed soft tissue sarcoma cohorts but has seldom been formally examined in extremity leiomyosarcoma. We assessed its prognostic value in a single-center cohort. Methods: We retrospectively studied 62 adults who underwent resection of primary localized extremity leiomyosarcoma at a tertiary sarcoma center between January 2015 and February 2025. Vascular invasion was reported contemporaneously at original diagnostic reporting by specialist sarcoma histopathologists. Overall (OS), disease-specific (DSS), local recurrence-free (LRFS), and metastasis-free (MFS) survival were estimated by the Kaplan–Meier method and compared using log-rank tests. Death from another cause was treated as a competing event for disease-specific death and distant metastasis in a sensitivity analysis. Multivariable Cox models were refitted using Firth’s penalized likelihood, with discrimination corrected for optimism by bootstrapping. Results: Median follow-up was 59.5 months. Five-year OS, DSS, and MFS were 71.0%, 80.2%, and 74.6%. Vascular invasion was reported in 11 of 62 patients (17.7%) and was associated with inferior OS (p = 0.002), DSS (p < 0.001), and MFS (p < 0.001), but not LRFS (p = 0.631). Adjusted for grade, it was associated with inferior OS (HR 3.89, 95% CI 1.35–11.26), DSS (HR 5.48, 95% CI 1.46–20.58), and MFS (HR 5.63, 95% CI 1.69–18.80). The association persisted on separate adjustment for tumor size, depth, and neoadjuvant radiotherapy. Conclusions: Vascular invasion was associated with inferior survival in localized extremity leiomyosarcoma. With 17 deaths and 14 metastatic events, these are exploratory estimates, but they support documenting vascular invasion explicitly, as present or absent, in routine histopathological reporting so that its role can be evaluated at scale.

Tendons are transitional tissues linking muscle to bone, enabling locomotion and fine motor control. The cellular biology across the Achilles tendon unit is poorly understood, yet critical for interpreting normal function and pathological changes across its microanatomically-defined functional zones. We generated a spatially-resolved transcriptomic atlas of human Achilles tendon, sampling the tendon-bone junction (enthesis), midbody, myotendinous junction, and adjoining muscle. Six fibroblast subtypes were identified, with distinct transcriptional profiles and spatial distributions, suggesting specialised functional roles across the tendon-muscle unit. Two dominant fibroblast types were specifically positioned in the tendon mid-substance and paratenon (vessel-rich region surrounding the tendon fibrils); other populations included perineural, myotendinous junction-specific, muscle-specific, and lining-layer fibroblasts. These findings demonstrate how cellular diversity across a transitional tissue may underlie microanatomical-specific roles. This atlas provides a foundation for understanding cellular functions across the tendon-muscle unit and will be essential for comparisons with diseased tissue, identifying pathogenic mediators and treatment targets for autoimmune and degenerative pathologies of the Achilles tendon.