Dermatofibrosarcoma Protuberans Presenting as a Primary Breast Mass.

Dermatofibrosarcoma protuberans (DFSP) is an atypical soft tissue malignancy that affects the dermis and subcutaneous tissue. The cause of DFSP is not clearly understood. This report highlights a rare case of DFSP of the left breast. We report a case of an 18-year-old female with past medical history of type 1 diabetes mellitus, who presented to the breast imaging clinic with a six-month history of left breast lump and associated skin discoloration. The patient had a dedicated left breast ultrasound which showed an indistinct, oval, hyperechoic mass in the superficial breast, measuring 1.4 x 1.0 x 2.5 cm with mild internal vascularity. An ultrasound-guided biopsy of this left breast mass was recommended and performed approximately three weeks later, demonstrating DFSP. The patient was then advised for consultation with Oncology, Surgical Oncology, and Radiation Oncology, to which surgical excision was the final recommendation. The patient had a wide local surgical excision procedure for her left breast mass with surgical pathology confirming negative margins shortly thereafter. This case highlights a great index of suspicion that should be taken when evaluating palpable breast masses with associated skin discoloration in young patients.

Exploring Localized Muscle Fatigue Responses at Current Upper-Extremity Ergonomics Threshold Limit Values.

OBJECTIVE: The purpose of this study was to evaluate localized muscle fatigue responses at three upper-extremity ergonomics threshold limit value (TLV) duty cycles. BACKGROUND: Recently, a TLV equation was published to help mitigate excessive development of localized muscle fatigue in repetitive upper limb tasks. This equation predicts acceptable levels of maximal voluntary contraction (% MVC) for a given duty cycle (DC). Experimental validation of this TLV curve has not yet been reported, which can help guide utilization by practitioners. METHOD: Eighteen participants performed intermittent isometric elbow flexion efforts, in three separate counter-balanced sessions, at workloads defined by the American Conference of Governmental Industrial Hygenists' (ACGIH) TLV equation: low DC (20% DC, 29.6% MVC), medium DC (40% DC, 19.7% MVC), and high DC (60% DC, 13.9% MVC). Targeted localized muscle fatigue (LMF) of the biceps brachii was tracked across numerous response variables, including decline in strength (MVC), electromyography (EMG) amplitude and mean power frequency (MnPF), and several psychophysical ratings. RESULTS: At task completion, biceps MnPF and MVC (strength) were significantly different between each TLV workload, with the high DC condition eliciting the largest declines in MnPF and MVC. CONCLUSION: Findings demonstrate that working at different DCs along the ACGIH TLV curve may not be equivalent in preventing excessive LMF. Higher DC workloads elicited a greater LMF response across several response variables. APPLICATION: High DC work of the upper extremity should be avoided to mitigate excess LMF development. Current TLVs for repetitive upper-extremity work may overestimate acceptable relative contraction thresholds, particularly at higher duty cycles.

Occult Pneumothorax Identification on Extended Focused Assessment with Sonography for Trauma Examination in Children.

OBJECTIVE: Occult pneumothoraces (OPTXs) are defined by air within the pleural space that is not visible on conventional chest radiographs (CXR). The aim of this study was to understand how frequently the Extended Focused Assessment with Sonography for Trauma (eFAST) examination identifies occult PTX in a pediatric blunt trauma population as compared with a criterion standard of chest computed tomography (CCT). METHODS: This study is a secondary analysis of blunt trauma patients younger than 18 years who underwent CCT at Los Angeles County +USC Medical Center Emergency Department from October 2015 to April 2017. The eFAST examination was performed and documented by an emergency medicine resident with attending oversight or by an emergency medicine attending for each trauma. The eFAST results were reviewed for patients diagnosed with small or trace pneumothoraces identified on CCT. RESULTS: Of 168 pediatric trauma patients undergoing CCT, 16 had OPTXs not seen on CXR and 4 patients had a small/trace PTX without a corresponding CXR performed. None were identified on eFAST. CONCLUSIONS: Although the sample size in this data set was small, our eFAST examinations identified none of 16 proven and 4 presumed OPTXs. The standard eFAST examination performed poorly in the detection of OPTXs in this single-center study of pediatric blunt trauma victims.

CT-guided cryoablation of mediastinal parathyroid adenoma: an alternative to surgery.

Primary hyperparathyroidism is most commonly caused by adenoma formation in one of the 4 parathyroid glands. The presence of ectopic parathyroid tissue is relatively common and can lead to difficulties in identification and treatment if affected by adenoma. This report describes the case of a 45-year-old female who presented 10 years status post thyroidectomy with symptomatic hyperparathyroidism and found to have ectopic parathyroid adenoma in the anterior mediastinum. Parathyroid scintigraphy with 99m-Technetium sestamibi and computed tomography were used for localization of the adenoma to a 1.9-centimeter para-aortic nodule. Computed tomography-guided transsternal cryoablation was subsequently performed for treatment, with intraoperative evaluation of serum parathyroid and calcium levels for confirmation. This case highlights that a sharp increase in parathyroid hormone immediately after cryoablation is not necessary for successful confirmation of the procedure. It additionally contributes to the growing literature on computed tomography-guided cryoablation as a legitimate alternative to surgery for treatment of ectopic parathyroid adenoma.

Lung cancer metastasis to the breast mimicking inflammatory breast carcinoma on imaging.

While metastatic disease to the breast has been documented from many primary neoplasms with incidence ranging from 0.2% to approximately 2.7% among reported clinical cases, breast cancer metastases resulting from a primary lung neoplasm is significantly less commonly reported in the literature. Routes of metastatic spread of lung neoplasms include both hematologic and lymphatic routes. We present a case of biopsy proven lymphangitic spread of primary lung neoplasm to the ipsilateral breast and axillary nodes mimicking inflammatory breast cancer. It remains crucial to differentiate between extramammary diseases with metastatic deposits in the breast from a primary breast neoplasm as treatment remains very different between these entities. As in this case, the pathologic, histologic, and immunohistochemistry analyses are critical in determining the origin of the malignant cells and formulating a treatment plan.

Muscle length and joint angle influence spinal but not corticospinal excitability to the biceps brachii across forearm postures.

Forearm rotation (supination/pronation) alters corticospinal excitability to the biceps brachii, but it is unclear whether corticospinal excitability is influenced by joint angle, muscle length, or both. Thus the purpose of this study was to separately examine elbow joint angle and muscle length on corticospinal excitability. Corticospinal excitability to the biceps and triceps brachii was measured using motor evoked potentials (MEPs) elicited via transcranial magnetic stimulation. Spinal excitability was measured using cervicomedullary motor evoked potentials (CMEPs) elicited via transmastoid electrical stimulation. Elbow angles were manipulated with a fixed biceps brachii muscle length (and vice versa) across five unique postures: 1) forearm neutral, elbow flexion 90°; 2) forearm supinated, elbow flexion 90°; 3) forearm pronated, elbow flexion 90°; 4) forearm supinated, elbow flexion 78°; and 5) forearm pronated, elbow flexion 113°. A musculoskeletal model determined biceps brachii muscle length for postures 1-3, and elbow joint angles (postures 4-5) were selected to maintain biceps length across forearm orientations. MEPs and CMEPs were elicited at rest and during an isometric contraction of 10% of maximal biceps muscle activity. At rest, MEP amplitudes to the biceps were largest during supination, which was independent of elbow joint angle. CMEP amplitudes were not different when the elbow was fixed at 90° but were largest in pronation when muscle length was controlled. During an isometric contraction, there were no significant differences across forearm postures for either MEP or CMEP amplitudes. These results highlight that elbow joint angle and biceps brachii muscle length can each independently influence spinal excitability. NEW & NOTEWORTHY Changes in upper limb posture can influence the responsiveness of the central nervous system to artificial stimulations. We established a novel approach integrating neurophysiology techniques with biomechanical modeling. Through this approach, the effects of elbow joint angle and biceps brachii muscle length on corticospinal and spinal excitability were assessed. We demonstrate that spinal excitability is uniquely influenced by joint angle and muscle length, and this highlights the importance of accounting for muscle length in neurophysiological studies.

Review of Interventions and Radiation Exposure from Chest Computed Tomography in Children with Blunt Trauma.

OBJECTIVE: To determine the radiation risk to a child undergoing trauma evaluation with chest computed tomography (CCT) for every clinically actionable injury identified. STUDY DESIGN: This observational, cross-sectional study included all blunt trauma patients under 18 years of age undergoing CCT in a single urban emergency department. Via a retrospective chart review, therapeutic interventions done exclusively for chest injuries identified on CCT scan were identified. Effective radiation from each CCT was calculated and averaged and the dose required to diagnose 1 management-changing chest injury was determined. RESULTS: Of 209 children undergoing CCT over a 19-month period, 168 were victims of blunt trauma. Ten required an intervention specifically for a chest injury identified on CCT (suggesting development of 1 malignancy per 37 actionable injures identified). None required an intervention for an injury exclusively noted on CCT, as all 10 actionable injuries were apparent via other modalities (radiograph, ultrasound examination, clinical examination). CONCLUSION: Although 10 uniquely actionable injuries were identified on CCT, none were found only on CCT. Because CCTs rarely modified management, the amount of radiation administered per management change was sufficiently high to recommend reconsideration of current imaging practice in this single-center study.