An unusual clinical presentation of myxoid dermatofibrosarcoma protuberans with a prominent vasculature: A potential pitfall in the diagnosis of myxoid soft tissue tumors

Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue tumor that arises primarily on the trunk and extremities but seldom on the scalp. Several variants of DFSP have been described, including myxoid DFSP. Although typical DFSP may have focally myxoid areas, myxoid DFSP, in which most of the stroma is myxoid, is rare and can pose diagnostic challenges. Here, we report a case of myxoid DFSP with an unusual clinical presentation that could have been mistaken for a lipoma. Additionally, the myxoid DFSP displayed prominent vasculature in a myxoid stroma, which could have been mistaken for a myxoid liposarcoma.     

Theoretical model for laser ablation outcome predictions in brain: calibration and validation on clinical MR thermometry images

Purpose: Neurosurgical laser ablation is experiencing a renaissance. Computational tools for ablation planning aim to further improve the intervention. Here, global optimisation and inverse problems are demonstrated to train a model that predicts maximum laser ablation extent.

Methods: A closed-form steady state model is trained on and then subsequently compared to N?=?20 retrospective clinical MR thermometry datasets. Dice similarity coefficient (DSC) is calculated to provide a measure of region overlap between the 57?°C isotherms of the thermometry data and the model-predicted ablation regions; 57?°C is a tissue death surrogate at thermal steady state. A global optimisation scheme samples the dominant model parameter sensitivities, blood perfusion (ω) and optical parameter (μ_eff) values, throughout a parameter space totalling 11?440 value-pairs. This represents a lookup table of μ_eff–ω pairs with the corresponding DSC value for each patient dataset. The μ_eff–ω pair with the maximum DSC calibrates the model parameters, maximising predictive value for each patient. Finally, leave-one-out cross-validation with global optimisation information trains the model on the entire clinical dataset, and compares against the model naïvely using literature values for ω and μ_eff.

Results: When using naïve literature values, the model’s mean DSC is 0.67 whereas the calibrated model produces 0.82 during cross-validation, an improvement of 0.15 in overlap with the patient data. The 95% confidence interval of the mean difference is 0.083–0.23 (p?Conclusions: During cross-validation, the calibrated model is superior to the naïve model as measured by DSC, with +22% mean prediction accuracy. Calibration empowers a relatively simple model to become more predictive.     

Vulnerability to Sympathetic Stress Does Not Persist in Takotsubo Stress Cardiomyopathy

ObjectiveOur objective was to investigate whether dobutamine stress echocardiography (DSE) could induce abnormal cardiac function in takotsubo stress cardiomyopathy (TSC) patients in a stable condition after the acute attack.Methods and ResultsThis was a case-control study and a substudy of the Stockholm Myocardial Infarction With Normal Coronaries (SMINC) study. Twenty-two patients with a previous episode of TSC and 22 sex- and age-matched control subjects were recruited from the SMINC study and investigated with the use of DSE. All TSC patients had a previous normal cardiovascular magnetic resonance investigation. Tissue Doppler imaging–derived time phases of the cardiac cycle were recorded to calculate myocardial performance index (MPI) to assess ventricular function. Compared with control subjects at rest, TSC patients had a slightly but significantly higher left ventricular MPI (LV-MPI; 0.53 vs 0.59; P = .01) and as a trend higher right ventricular MPI (0.38 vs 0.47; P = .08), although during DSE these variables did not differ significantly.ConclusionWe found no difference in standard diastolic parameters between TSC and control subjects, but a significant higher value in LV-MPI in the TSC group at rest. However, no such difference could be demonstrated during DSE between the groups, indicating that vulnerability to sympathetic stimulation does not persist in TSC patients.     

Direct and reversed dorsal digital island flaps: A review of 65 cases

BackgroundReconstruction of soft tissue defects in fingers continues to be a challenging problem. The purpose of this study is to report the reconstruction of small-to-moderate defects of fingers with dorsal digital island flap (DDIF) and to evaluate the efficacy of use of the flap.MethodsOver last six years, a retrospective study was conducted with 65 patients who had soft tissue defects of fingers treated with the DDIF. Sixty-nine soft-tissue defects were found in 69 fingers in 65 patients. Based on the flow direction of blood supply, the patients were divided into two groups: the direct (n = 35) and reversed (n = 30) DDIF groups. In addition, based on the different donor sites, the direct DDIF group was divided into two subgroups: the proximal phalangeal direct DDIF subgroup (n = 16) and the extended pedicle direct DDIF subgroup (n = 19). The main outcomes were static 2-point discrimination and Semmes–Weinstein monofilament scores of flap and joint motion.ResultsAt the final follow-up, the mean static two-point discrimination of the flaps was 9.7 mm (range, 8 to 12 mm) in the proximal phalangeal direct DDIF subgroup and 8.3 mm (range, 7 to 11 mm) in the extended pedicle direct DDIF subgroup, with a significant difference (p = 0.005). In the direct DDIF group, there was no significant difference in total active motion between the donor fingers and the opposite sides. In the reversed DDIF group, the mean total active motion of the donor fingers was 170° and the data of the opposite sides was 181°, with a significant difference (p = 0.024). Maximum amplitude losses of 15° were seen in 12% of patients in the distal interphalangeal joint.ConclusionsThe DDIF is reliable and technically easy for reconstructing small-to-moderate defects of fingers. The extended pedicle direct DDIF may be an optional solution when sensory reconstruction is needed.     

Dysregulation of oxygen hemodynamic responses to synaptic train stimulation in a rat hippocampal model of subarachnoid hemorrhage

We investigated microvascular reactivity to synaptic train stimulation after induction of subarachnoid hemorrhage in adult rats, analyzing tissue oxygen levels [pO₂] in intact hippocampus. In control rats, hippocampal pO₂ averaged 11.4 mm Hg whereas hemodynamic responses averaged 13.1 mm Hg (to a 25 s train). After subarachnoid hemorrhage (at 2 days), we recorded a dramatic elevation in baseline pO₂ in the hippocampus (to 68.4 mm Hg) accompanied by inverted pO₂ responses to synaptic train stimulation (−9.46 mm Hg). These significant changes in baseline hippocampal pO₂ and inverted pO₂ responses after subarachnoid hemorrhage indicate severe alterations of neurovascular coupling and neuronal viability.     

Atomic force microscopy for biomechanical and structural analysis of human dermis: A complementary tool for medical diagnosis and therapy monitoring

Skin mechanical properties are usually measured considering the entire skin thickness and very little is known about the mechanical behaviour of individual skin layers. We propose atomic force microscopy (AFM) as a tool to quantify nanoscale changes in the biomechanical properties and ultrastructure of human papillary dermis exposed to different mechanical and physical stimuli. Samples from 3 human skin biopsies were studied: one stretched by obesity, one subjected to a high level of sun exposure and normal skin as control. Slices of the papillary dermis layer were harvested at controlled depths from each skin biopsy and 25 μm² areas of each slice were imaged and D‐periodicity of collagen fibres measured by AFM, together with their stiffness. Standard histological analysis was also carried out to correlate biochemical properties and their distribution with stiffness and topography. We obtained similar stiffness values between the sample affected by obesity and the control sample at any depth level into the dermis, while the sun‐exposed sample presented a significantly lower stiffness. Additionally, all samples presented an increase in the stiffness at higher depths into the papillary dermis layer. Collagen fibres close to the epidermis of sample affected either by obesity and sun exposure—the former even more than the latter—are thicker and present a larger D‐period than those in the control sample. Our results open the possibility to use structural and mechanical analysis based on AFM as a complementary tool for medical diagnosis and therapy monitoring.     

A totally laparoscopic peritoneal free flap for reconstruction of hand

Management of defects on the hand and foot with exposed tendons remains a major challenge for plastic surgeons. Here, we present a case of hand reconstruction with a totally laparoscopic peritoneal flap. The anterior rectus sheath was preserved in situ. The peritoneal free flap supplied by peritoneal branches of the deep inferior epigastric artery was retrieved by laparoscopy to cover the soft tissue defect of the hand. The defect of the dorsal hand was 17 cm * 12 cm. The peritoneal flap measuring 22 cm * 15 cm survived completely without any complications. A following split-thickness skin graft offered the successful wound closure. Motor and sensory function improved gradually within the first year follow-up. The totally laparoscopic peritoneal free flap is a good choice for reconstruction of the soft tissue defects accompanied by exposed tendons on the hand and foot.