Corrigendum to "Juxta-articular extraskeletal myxoid chondrosarcoma mistaken for a benign cyst presenting with multiple lung metastases" [Radiology Case Reports 19 (2024) 684-690].

[This corrects the article DOI: 10.1016/j.radcr.2023.10.075.].

Juxta-articular extraskeletal myxoid chondrosarcoma mistaken for a benign cyst presenting with multiple lung metastases.

Extraskeletal myxoid chondrosarcoma (EMC) is a malignant cartilage neoplasm usually encountered in the proximal extremities. We report the case of a 58-year-old male who presented initially with a 3-month history of cough. Initial staging demonstrated a right upper lobe mass with bilateral pulmonary nodules and moderate tracer uptake in the right lung mass and right groin on positron emission tomography imaging. Endobronchial ultrasound biopsy confirmed a histological diagnosis of EMC for which the patient underwent right upper lobe wedge resection. Pelvic MRI revealed a peripherally enhancing juxta-articular lesion within the region of the right obturator externus bursa, which was thought initially to represent either a ganglion or paralabral cyst. However, ultrasound-guided biopsy yielded identical histology to the resected lung mass leading to the diagnosis of primary EMC in the right groin with pulmonary metastases. The patient underwent surgical excision of the right groin mass with no local recurrence on the surveillance computed tomography at 5, 12, and 18 months but eventual disease recurrence in the right groin and further progression of the pulmonary metastases at 29 months. We emphasize that the contrast enhancement pattern of EMC can mimic a benign cystic lesion, in particular, when in a juxta-articular location, which has the potential to mislead radiologists and delay diagnosis and definitive treatment.

Acute haemorrhage rate in 28,000 Out-of-Hours CT heads.

OBJECTIVES: The aim of this paper is to assess the acute haemorrhage rate in patients who had CT head investigation out-of-hours with and without trauma and compare the rates of haemorrhage between warfarin and DOACs, at a busy teritary teaching hospital. METHODS: All CT heads performed between January 2008 and December 2019 were identified from the radiology information system (RIS) at Sheffield Teaching Hospitals (STH), with the requesting information being available from January 2015. The clinical information was assessed for the mention of trauma or anticoagulation, and the reports were categorised into acute and non-acute findings. RESULTS: Between 2008 and 2019 the number of scans increased by 63%, with scans performed out of hours increasing by 278%. Between 2015 and 2019, the incidence of acute ICH was similar over the 5-year period, averaging at 6.9% and ranging from 6.1 to 7.6%. The rate of detection of acute haemorrhage following trauma was greater in those not anticoagulated (6.8%), compared with patients on anticoagulants such as warfarin (5.2%) or DOACs (2.8%). CONCLUSIONS: Over 12 years, there has been a significant increase in the number of CT heads performed at STH. The rate of ICH has remained steady over the last 5 years indicating a justified increase in imaging demand. However, the incidence of ICH in patients prescribed DOACs is lower than the general population and those on warfarin. ADVANCES IN KNOWLEDGE: This finding in a large centre should prompt discussion of the risk of bleeding with DOACs in relation to CT head imaging guidelines.

Extensor Digitorum Brevis Manus presenting as a symptomatic lump on the dorsum of the hand.

Lumps in the hand are a common presenting complaint in General Practice. We present the case of a 24-year-old male who presented to his General Practitioner with a painful lump in the dorsum of his right hand. He was referred to the sarcoma services where MRI and ultrasound examinations revealed an accessory Extensor Digitorum Brevis Manus muscle as the cause of the patient's symptoms. When patients present with a painful or discomforting lump in the dorsum of the hand during or after repetitive use, typically on flexion, a diagnosis of Extensor Digitorum Brevis Manus should be considered.

Off-label magnetic resonance imaging of an InterStim II sacral nerve stimulator device.

The InterStim II (Medtronic, Inc., Minneapolis, MN) sacral nerve stimulator has been approved for MRI scanning of the head only. All other body areas are contraindicated by the manufacturer. This report presents the successful MRI examination of the left hand in a patient with an InterStim II device. Following an assessment of the risks and benefits of proceeding with the scan it was shown that there were minimal additional risks, which could be easily managed with appropriate patient positioning, coil selection and other established techniques. Informed consent was obtained and the scan completed without incident. Following the scan the patient reported full functioning of the device. MRI of the hand is feasible in patients with InterStim II implants using transmit/receive coils with appropriate risk controls in place. Further study of the safety of MRI of other body regions in InterStim II patients is appropriate.

The management of deep-seated, lowgrade lipomatous lesions.

Deep-seated, low-grade lipomatous lesions detected on imaging often cause uncertainty for diagnosis and treatment. Confidently distinguishing lipomas from well-differentiated liposarcomas is often not possible on imaging. The approach to management of such lesions varies widely between institutions. Applying an evidenced-based approach set around published literature that clearly highlights how criteria such as lesion size, location, age and imaging features can be used to predict the risk of well-differentiated liposarcomas and subsequent de-differentiation would seem sensible. Our aim is to review the literature and produce a unified, evidence-based guideline that will be a useful tool for managing these lesions.

Imaging features of osteoid osteoma of the phalanges.

OBJECTIVES: Osteoid osteoma (OO) of the phalanges is regarded as a difficult diagnosis to make, both clinically and radiologically. Our aim was to assess the imaging features of this relatively rare entity to assess for consistent imaging features. MATERIALS AND METHODS: Retrospective analysis of databases at our institutions was performed to identify patients with histologically confirmed OO of the phalanges. Radiographs were assessed for a nidus, surrounding sclerosis, periosteal reaction, cortical erosion and generalised soft tissue swelling. MRI scans were reviewed for visibility of the nidus; reactive marrow oedema; periostitis; and a soft tissue mass associated with the lesion. RESULTS: Ten patients with OO occurring in a phalanx were identified. Nine out of ten patients (90%) were male. The mean age was 20 years (range 11-45). At radiography, a nidus was visible in 100% (10 out of 10) cases. Internal matrix within the nidus was seen in 60% (6 out of 10). Sclerosis surrounding the nidus was present in 90% (9 out of 10). Cortical erosion was identified in 10% (1 out of 10). Generalised swelling of the affected digit was noted in 100% (10 out of 10). Periosteal/cortical sclerosis was seen in 20% (2 out of 10). Of the 8 patients who had an MRI scan, the nidus was visible in 100% (8 out of 8). Reactive marrow oedema within the affected phalanx was present in 100% (8 out of 8). There was a soft tissue mass surrounding the affected phalanx in 75% (6 out of 8). Periosteal oedema was noted in 13% (1 out of 8). CONCLUSION: Phalangeal OO demonstrates similar imaging appearances to OO at other locations in the majority of cases. An inflammatory soft tissue mass often accompanies the nidus at MRI.

An aggressive case of pseudomyogenic haemangioendothelioma of bone with pathological fracture and rapidly progressive pulmonary metastatic disease: case report and review of the literature.

Pseudomyogenic haemangioendothelioma (PMH) is a rare recently described vascular tumour typically presenting with soft tissue disease in distal extremities of young adults. Multi-focal and multi-layered involvement is commonly recognised. The majority of cases described so far have shown an indolent clinical course and distant metastatic spread is rare. We report a case of PMH in an 82-year-old male diagnosed following a pathological fracture of the distal tibia. Further bone lesions were identified in the fibula, patella and distal femur. The patient was found to have multiple nodules suspicious for pulmonary metastases on a CT scan at the time of diagnosis that showed significant progression at a follow-up scan 4 weeks later. To our knowledge, this is the first reported case of PMH presenting with a pathological fracture. The rapid progression of bone and distant metastatic disease in this case is highly unusual given the typically indolent clinical course reported in the literature to date.

Cumulative radiation dose due to diagnostic investigations in seriously injured trauma patients admitted to critical care.

A retrospective review of case notes and radiology records was performed in order to estimate the amount and sources of ionising radiation multiply injured trauma patients are exposed to, during their initial investigations and subsequent critical care admission. Data were available for 431 radiological investigations from 36 patients. Results showed initial emergency department imaging (combined computed tomography (CT) and plain radiographs) contributed 70% of the total radiation dose. Overall, CT scans were responsible for 80% and plain radiographs 15% of the total radiation dose. Plain radiographs performed after the initial resuscitation period contributed the greatest number of investigations but accounted for only 8% of total radiation exposure. Median cumulative effective dose was estimated to be between 16 and 29 millisieverts, resulting in an estimated increased life time risk of carcinogenesis of between 1 in 614 and 1 in 1075 above baseline.

MR imaging features of spindle cell lipoma.

OBJECTIVE: To assess the MR imaging features of spindle cell lipomas (SCL) and to compare these appearances directly with the histopathological findings. MATERIALS AND METHODS: A retrospective review of our soft tissue tumor database was performed. This yielded 1,327 histologically proven lipomas, of which 25 were confirmed as being SCLs. Fourteen of the 25 patients had MR examinations available for review and only these patients were included in our study. Lesions were assessed at MR examination for the degree of internal fat signal content with grade 0 representing 0 % fat signal and grade 4 100 % fat signal. The degree of fat suppression and contrast-enhancement pattern were also recorded. The excision specimens were independently reviewed by a consultant histopathologist. The histology specimens were assessed for the amount of internal fat and non-adipose tissue and graded using the same scale applied for the imaging. Where core needle biopsy (CNB) was performed, the CNB specimens were also examined for positive features of SCL. RESULTS: In our study, 93 % (13/14) of our patients were male and the average age was 58 years. 65 % (9/14) of the lesions presented in the upper back, shoulder, or neck. All lesions were subcutaneous. 35 % (5/14) of the SCLs demonstrated grade 3 (>75 %) or grade 4 (100 %) fat signal on MR examination. 35 % (5/14) of the lesions had grade 2 (25-75 %) fat signal and 29 % (4/14) of the lesions demonstrated grade 0 (0 %) or grade 1 (<25 %) fat signal. 43 % (6/14) of lesions demonstrated homogenous fat suppression, 28 % (4/14) showed focal areas of high internal signal, and 28 % (4/14) had diffuse internal high signal on fluid-sensitive fat-saturated sequences. 86 % (6/7) of the cases demonstrated septal/nodular enhancement. The diagnosis was evident on the CNB specimen in 100 % (9/9) cases. The histopathology fat content grade was in agreement with the imaging grade in 86 % (12/14) cases. CONCLUSIONS: The internal signal pattern of SCL can range broadly, with low fat content lesions seen almost as commonly as intermediate and high fat content lesions. We also found that the fat:non-fat internal MR signal pattern of these lesions is accurately reflected in their composition at histology.

Paraspinal chordoma mimicking a neurofibroma: a rare but important radiological pitfall.

We present an unusual case of a chordoma presenting as an extradural spinal tumour with extension through an expanded intervertebral foramen to form a large paraspinal mass. The magnetic resonance imaging appearances closely mimicked a neurofibroma; however, pre-operative biopsy confirmed the diagnosis of chordoma. This is, to our knowledge, the tenth reported case of chordoma presenting as a mass expanding the intervertebral foramen. Thus, while it is a rare form of chordoma, it can lead to a recognised radiological pitfall. Making the distinction from neurofibroma before surgery is essential, as radical dissection of chordoma is required to reduce the risk of local recurrence.

Lateral epicondylitis and beyond: imaging of lateral elbow pain with clinical-radiologic correlation.

The diagnosis of lateral epicondylitis is often straightforward and can be made on the basis of clinical findings. However, radiological assessment is valuable where the clinical picture is less clear or where symptoms are refractory to treatment. Demographics, aspects of clinical history, or certain physical signs may suggest an alternate diagnosis. Knowledge of the typical clinical presentation and imaging findings of lateral epicondylitis, in addition to other potential causes of lateral elbow pain, is necessary. These include entrapment of the posterior interosseous and lateral antebrachial cutaneous nerves, posterolateral rotatory instability, posterolateral plica syndrome, Panner's disease, osteochondritis dissecans of the capitellum, radiocapitellar overload syndrome, occult fractures and chondral-osseous impaction injuries, and radiocapitellar arthritis. Knowledge of these potential masquerades of lateral epicondylitis and their characteristic clinical and imaging features is essential for accurate diagnosis. The goal of this review is to provide an approach to the imaging of lateral elbow pain, discussing the relevant anatomy, various causes, and discriminating factors, which will allow for an accurate diagnosis.

Medial ankle and heel: ultrasound evaluation and sonographic appearances of conditions causing symptoms.

The complex anatomy of the medial ankle and hindfoot can make clinical assessment of medial ankle and heel pain challenging. Ultrasound is an accessible, relatively inexpensive modality, and modern high-resolution probes allow eloquent demonstration of the main structures that are implicated as potential causes of medial ankle pain. In this work we review highlights the clinically relevant anatomy and normal sonographic appearances of structures around the medial ankle and heel and discuss key techniques to allow optimal ultrasound assessment. The conditions that cause medial-sided ankle and heel symptoms are discussed with their characteristic sonographic appearances.

MR imaging of skeletal soft tissue infection: utility of diffusion-weighted imaging in detecting abscess formation.

PURPOSE: Our objectives were to assess if diffusion-weighted imaging (DWI) can help identify abscess formation in the setting of soft tissue infection and to assess whether abscess formation can be diagnosed confidently with a combination of DWI and other unenhanced sequences. METHODS: Eight cases of soft tissue infection imaged with MRI including DWI were retrospectively reviewed. RESULTS: Two male and six female patients were studied (age range 23-50 years). Unenhanced MRI including DWI was performed in all patients. Post-contrast images were obtained in seven patients. All patients had clinically or surgically confirmed abscesses. Abscesses demonstrated restricted diffusion. DWI in conjunction with other unenhanced imaging showed similar confidence levels as post-contrast images in diagnosing abscess formation in four cases. In two cases, although the combined use of DWI and other unenhanced imaging yielded the same confidence levels as post-contrast imaging, DWI was more definitive for demonstrating abscess formation. In one case, post-contrast images had a better confidence for suggesting abscess. In one case, DWI helped detected the abscess, where gadolinium could not be administered because of a contraindication. CONCLUSION: This preliminary study suggests that DWI is a useful adjunct in the diagnosis of skeletal soft tissue abscesses.

Chronology of the radiographic appearances of the calcium sulphate-calcium phosphate synthetic bone graft composite following resection of bone tumours--a preliminary study of the normal post-operative appearances.

OBJECTIVE: To describe the normal chronological radiographic appearances of the calcium sulphate-calcium phosphate (CaSO(4)/CaPO(4)) synthetic graft material following bone tumour resection during the processes of graft resorption and new bone incorporation into the post-resection defect. MATERIALS AND METHODS: Retrospective review of our oncology database identified patients who had undergone serial radiographic assessment after treatment with the CaSO(4)/CaPO(4) synthetic graft following bone tumour resection. Post-operative radiographs were assessed for (1) partial resorption of graft material with partial ingrowth of new bone at the graft site and (2) complete resorption of graft material with complete incorporation of new bone into the graft site. The pattern of resorption of graft material was also documented. Any radiographic evidence of complication was recorded. Radiographs were also divided into groups according to their interval from surgery to establish a pattern of time-related changes. RESULTS: A total of 11 patients were identified from our database. Partial resorption of graft material/partial ingrowth of new bone was seen in nine patients, initially observed at a mean of 1.4 months from surgery. Resorption commenced peripherally with gradual inward progression in 100% (9 of 9) of cases. Complete resorption of graft/complete new bone incorporation at the graft site was seen in 89% (8 of 9) of cases followed up for more than 5 months after surgery. The other patient developed recurrence of tumour at 14 months, before complete incorporation was demonstrated. The mean time to complete incorporation of new bone was 5 months. Two patients have, to date, been followed up at 2 and 3 months respectively with a pattern of peripheral graft resorption observed so far in both cases. Ten of 13 (77%) radiographs performed 1-3 months after surgery demonstrated peripheral resorption of graft material with partial osseous ingrowth into the defect. Seven of eight (88%) radiographs performed 6-12 months after surgery demonstrated complete new bone incorporation at the graft site with graft material completely resorbed. Ten of 11 (91%) radiographs performed 1 year after surgery demonstrated complete new bone incorporation, the other examination demonstrating recurrence. CONCLUSION: Our preliminary observations suggest a characteristic, time-related radiographic pattern during the processes of CaSO(4)/CaPO(4) bone graft resorption and complete new bone incorporation. This pattern can be directly related to processes that occur at the molecular level. Radiographic findings that are not in keeping with this may merit closer follow-up.

Magnetic resonance imaging appearances following hindquarter amputation for pelvic musculoskeletal malignancy.

OBJECTIVE: To describe our experience of the magnetic resonance imaging (MRI) appearances after hindquarter amputation, focusing on the normal pattern of time-related changes in signal intensity within the amputation flap and appearances of local disease recurrence. MATERIALS AND METHODS: This was a retrospective review of the records of patients identified on our orthopaedic oncology database who had undergone hindquarter amputation at our centre. Examinations were divided into one group consisting of 'normal' postoperative findings and another group demonstrating local recurrence. 'Normal' postoperative findings were assessed for signal intensity, morphology and presence of the 'muscle texture sign' within the amputation flap. Examinations were grouped according to time from surgery. Examinations demonstrating local recurrence were assessed for site, signal intensity, morphology and axial dimensions of recurrent tumour. Comparison was made to pre-operative imaging. RESULTS: Thirty-five patients with postoperative MR images were identified. Seventy-seven examinations were reviewed (range 1-18 per patient). The 'normal group' comprised 18 patients (seven female, 11 male, mean age 44 years, range 16-75 years), with 47 examinations reviewed. The 'muscle texture sign' was preserved in all examinations in this group. Up to 6 months after surgery, 100% (10) of examinations showed hyperintense T2- and short-tau inversion recovery (STIR-weighted) signals within the muscle flap, indicating oedema. Only after 4 years was the muscle flap signal isointense in all cases (13). Up to 6 months after surgery, 50% (5 of 10) of examinations demonstrated flap swelling, but after 1 year, 100% (28) showed atrophy. Twenty percent (2 of 10) of examinations 0-6 months from surgery showed hyperintense T1-weighted signal within the muscle flap, consistent with fatty infiltration, but after 2 years, 100% (20) showed a hyperintense T1-weighted signal. The 'local recurrence' group comprised 20 patients (six female, 14 male, mean age 45.7 years, range 14-69 years), with 30 examinations demonstrating recurrent disease or metastasis. There were 23 recurrent tumours, of which 43% (10) were in the muscle component of the amputation flap, 13% (3 of 23) were in subcutaneous tissues of the flap, 13% (3 of 23) were at the posterior margin of the bone resection and 13% (3 of 23) were paraspinal. All recurrent tumours demonstrated hyperintense T2 and STIR signals. The signal intensity pattern of recurrence closely followed that of the original tumour. The 'muscle texture sign' was absent in all examinations demonstrating recurrence in muscle flap. CONCLUSION: A pattern of time-related signal intensity and morphological changes is observed within normal hindquarter amputation flaps on MRI. Recurrent disease is most likely to occur within the muscle flap, typically of high T2-weighted signal intensity and characteristically follows the signal pattern of the original tumour.