Myositis ossificans revisited - The largest reported case series

Reviewing superficial bone lesions: What the radiologist needs to know

Superficial bone lesions arise from the outer components of the bone, from the cortex to the periosteum. Such superficial lesions are often challenges during imaging reporting, and their incorrect interpretation may lead to inadequate management. We present a literature review regarding these lesions according to a standardized division into tumoral and non-tumoral lesions. We also provide a guide for their proper assessment on different imaging modalities. Knowledge of the specific imaging features that aid in the determination of the lesion origin and estimation of the risk of malignancy is fundamental for the radiologist to contribute to adequate patient management.

Neglected Elbow Injury With Severe Flexion Deformity With Myositis Ossificans

Myositis ossificans is a rare entity of extra-skeletal bone formation in various soft tissues and muscles, often triggered by trauma or injury. We report a case of myositis ossificans traumatica in a 45-year-old female who presented with pain and a fixed flexion deformity of the elbow. Imaging studies, including X-ray and magnetic resonance imaging (MRI), revealed a bony mass in the posterior aspect of the right elbow and presence of triceps injury. The patient underwent surgical excision with arthrolysis. To prevent further heterotopic bone formation, excessive massaging or rubbing of the affected area was avoided. The postoperative period was uneventful.

A pictorial review of osseous and cartilaginous soft tissue tumours

Osseous and cartilaginous soft tissue tumours are a heterogenous group of neoplasms characterised by the presence of an osseous or cartilaginous component. Mineralisation of the osseous or cartilaginous component is a common finding amongst these lesions, presenting as calcification/ossification on radiological imaging. This pictorial review examines the key imaging findings and characteristics of osseous and cartilaginous soft tissue tumours with a focus on the distinguishing features which can help the radiologist to differentiate benign and malignant lesions. All examples provided are of histopathologically proven cases seen in our tertiary referral soft tissue sarcoma centre.

Recalcitrant Ulnar-Sided Hand Pain in a Collegiate Golfer: A Case Report

ABSTRACT

This case report details a diagnosis of myositis ossificans in a collegiate golfer with right ulnar-sided hand pain after striking the ground on a swing. Despite conservative treatment and a thorough workup, the patient's ulnar-sided hand pain did not improve. An ultrasound eventually revealed myositis ossificans within the abductor digiti minimi muscle. The patient received an ultrasound-guided fenestration and injection of lidocaine and dexamethasone into the affected muscle, leading to complete symptom resolution. Myositis ossificans is often secondary to trauma, causing bone formation in soft tissue, leading to pain, limited range of motion, and disability. This case highlights the importance of considering myositis ossificans in cases of persistent muscular pain and the diagnostic challenges related to ulnar-sided hand anatomy.

Sarcoma or haematoma? If only it was that simple! Part 1

Introduction

Imaging appearances and clinical presentation of soft tissue sarcoma and soft tissue haematomas are similar. It is imperative that sarcoma is differentiated from benign soft tissue lesions due to the poor outcomes and high morbidity associated with sarcoma.

Topic description

Part 1 of this pictorial review will summarise the paucity of guidance in management of suspected haematomas, the clinical features and ultrasound techniques used in the assessment of soft tissue masses.

Discussion

Ultrasound is the first-line test in the investigation of soft tissue masses. With the overlapping ultrasound appearances of soft tissue sarcoma and soft tissue haematoma, thorough and methodical clinical examination and scanning technique is fundamental so that practitioners understand when to escalate cases for further investigation.

Conclusion

The clinical assessment and clinical history taking into consideration the intensity of trauma and ecchymosis must correlate with the ultrasound appearances. This will facilitate an accurate diagnosis, timely management and improved patient outcomes.

Non-traumatic Myositis Ossificans Mimicking Infected Hip in Children: Two Case Reports and Review of the Literature

We present two pediatric cases of nontraumatic myositis ossificans (MO), which initially mimicked infections, leading to unnecessary treatments. The first case involves an 11-year-old boy with acute left hip pain and swelling, misdiagnosed as a hip joint infection and treated with antibiotics before histology confirmed MO. The second case is a two-year-old girl who presented with limping and restricted hip movement, initially suspected to have septic arthritis. Following MRI and clinical reassessment, her condition was diagnosed as MO. Both cases highlight the challenges of diagnosing MO in children and underscore the importance of including it in differential diagnoses for suspected infections.

Myositis ossificans mimicking bone surface osteosarcoma: case report with literature review

Myositis ossificans, a benign tumor composed of spindle cells and osteoblasts, can clinically and radiologically mimic osteosarcoma. While recognition and accurate diagnosis of myositis ossificans can be a challenge, this is critical as it may allow a conservative surgical approach to maximize functional outcomes. Herein, we present a patient with surface myositis ossificans confirmed genetically by the presence of COL1A1::USP6 gene fusion, along with a literature review. Due to the enhanced visualization of the bone matrix, computed tomography (CT) imaging may be a superior imaging modality to magnetic resonance (MR) imaging. Staged biopsies with samples obtained from the periphery and center of the lesions may allow pathologists to discern the zonal distribution histologically. Furthermore, immunohistochemistry fluorescence in situ hybridization and molecular testing can aid in the distinction of myositis ossificans from mimics. Because of their resemblance to other bone tumors, these cases of myositis ossificans highlight the importance of a multidisciplinary approach integrating clinical, radiologic, and pathologic analysis and involving serial imaging, sampling, and judicious use of ancillary immunohistochemical and molecular testing.

Myositis ossificans in the chest wall: A case report

Myositis ossificans is delineated and distinguished by the generation and deposition of cartilaginous and osseous soft tissues. It generally occurs in the lower extremities and is caused by direct trauma. During the different developmental stages of maturation, the lesion has different radiological appearances that can be confused with sarcomas. Here, we present the case of a 38-year-old woman who presented to the outpatient clinic with a painful mass in the lateral chest wall that had rapidly expanded and increased in size. The patient had no history of trauma. Chest computed tomography revealed an intramuscular mass in the lateral chest wall; postcontrast images demonstrated heterogeneous enhancement and peripheral calcification. The patient was then referred to our center for subsequent assessment and examinations. Pathological examination findings confirmed the diagnosis of myositis ossificans. Surgical resection was performed after obtaining patient consent. The symptoms experienced by the patient were successfully relieved, and no evidence of recurrence was observed during the 2-year follow-up period. Knowledge of the atypical locations of myositis ossificans, calcification patterns at different stages, and radiopathological correlations can help accurately diagnose myositis ossificans and avoid unnecessary medical imaging and interventions.

Incidental Intense Fibroblast Activation Protein Inhibitor (FAPI) Uptake in Bilateral Gluteal Myositis Ossificans: A Case Report

Positron emission tomography/computed tomography (PET/CT) using 18F-fluorodeoxyglucose ([18F]-FDG) is a widely adopted imaging modality for detecting hypermetabolic lesions. However, emerging positron-emitting tracers, such as radiopharmaceuticals featuring fibroblast activation protein (FAP) inhibitors (FAPI) labeled with [18F] or [68Ga], have opened new avenues in nuclear medicine. This case report focuses on the unique behavior of [68Ga]-FAPI in bilateral gluteal myositis ossificans, an infrequent condition characterized by soft tissue ossification. A 45-year-old woman with gastric adenocarcinoma underwent subtotal gastrectomy and received neoadjuvant and adjuvant chemotherapy; [68Ga]-FAPI PET revealed metastatic processes and unexpected [68Ga]-FAPI avid intramuscular ossifications in the pelvic and bilateral thigh muscles. Even though there was no history of trauma, the patient was diagnosed with myositis ossificans, a condition marked by non-cancerous ectopic ossifications. Diagnosis relies on history, radiology, and/or histology. FAPI imaging, increasingly used for inflammatory and infectious diseases, can exhibit uptake in benign conditions, including those involving bones and joints. This case report is the first to document incidental bilateral [68Ga]-FAPI uptake in bilateral gluteal myositis ossificans. The robust [68Ga]-FAPI activity in myositis ossificans highlights the importance of considering myositis ossificans in the context of soft tissue calcifications with intense [68Ga]-FAPI uptake.

Genetic regulation of injury-induced heterotopic ossification in adult zebrafish

Heterotopic ossification is the inappropriate formation of bone in soft tissues of the body. It can manifest spontaneously in rare genetic conditions or as a response to injury, known as acquired heterotopic ossification. There are several experimental models for studying acquired heterotopic ossification from different sources of damage. However, their tenuous mechanistic relevance to the human condition, invasive and laborious nature and/or lack of amenability to chemical and genetic screens, limit their utility. To address these limitations, we developed a simple zebrafish injury model that manifests heterotopic ossification with high penetrance in response to clinically emulating injuries, as observed in human myositis ossificans traumatica. Using this model, we defined the transcriptional response to trauma, identifying differentially regulated genes. Mutant analyses revealed that an increase in the activity of the potassium channel Kcnk5b potentiates injury response, whereas loss of function of the interleukin 11 receptor paralogue (Il11ra) resulted in a drastically reduced ossification response. Based on these findings, we postulate that enhanced ionic signalling, specifically through Kcnk5b, regulates the intensity of the skeletogenic injury response, which, in part, requires immune response regulated by Il11ra.

Myositis Ossificans Traumatica of Bilateral Sternocleidomastoid Muscles After Chiropractor Adjustment: A Case Report

A woman in her 20s with a past medical history of surgical debulking of a right neck mass presented to the hospital for persistent and worsening right shoulder pain. The shoulder pain was associated with trismus and back and neck pain. A CT scan of the neck with contrast revealed post-surgical changes with increased heterotopic ossification throughout the surgical site extending to the supraclavicular soft tissues and the left sternocleidomastoid muscle, suggesting muscle ossification. A biopsy was performed, and the patient was diagnosed with myositis ossificans (MO). Initial treatment began with the administration of steroids and analgesics. She was scheduled for a follow-up with orthopedics, rheumatology, and genetics, but she was lost for follow-up. MO is a very rare medical condition usually associated with trauma, and in our patient, the symptoms started after a chiropractic adjustment.

Periostitis Ossificans: Largest Case Series with Review of Literature

Background  Periostitis ossificans (PO) are rare, benign ossifying surface lesions characterized by the centripetal ossification with osseous and soft-tissue edema. Their clinicoradiological appearances can easily mimic those of more sinister or infective surface lesion. Objective  This study aimed to explore the various anatomical locations and muscle attachment at the site of PO, and evaluate the role of complementary image findings in patients presenting at our tertiary orthopaedic referral center. Patients and Methods  A retrospective review of our oncology and radiology databases was undertaken to identify patients with PO reported on radiographs, magnetic resonance imaging (MRI) and computed tomography (CT) over the past 13 years (2007-2020). Patient demographics, sites of PO, muscle attachment at the site of PO, findings on complementary imaging, and clinical management outcome were documented. Results We identified 38 patients with PO with a mean age of 24 years (range: 4-66 years). Muscle attachment was seen at the site of PO in the majority of cases (89%). The majority of PO were in the lower limb and commonly seen around the attachment of quadriceps. Deltoid attachment was commonly involved in the upper limb. Conclusion  Muscle attachment is commonly seen at the site of PO, which results in stripping of the periosteum resulting in soft-tissue and osseous edema and centripetal ossification.

Myositis ossificans in the pediatric population: a systematic scoping review

Introduction

Circumscribed or pseudomalignant myositis ossificans (MO) is a rare and benign condition characterized by heterotopic bone formation in soft tissues. The clinical presentation of MO, imaging investigations, histological findings, and treatment strategies are unclear, especially in the pediatric population.

Materials and methods

A literature search was conducted in PubMed, Scopus, and Google Scholar electronic databases to identify original articles and reviews in English or French of traumatic and non-traumatic MO. Studies were selected by 2 independent reviewers following the PRISMA recommendation and descriptive data were extracted. We harvest in each case the sex, age at diagnosis, location, presence of initial trauma, pre-emptive diagnosis, modalities of imagery used, realized biopsy, treatment performed, and type of follow-up.

Results

Sixty pediatric cases of MO were identified between 2002 and 2023. Twenty-three patients (38.3%) were diagnosed with idiopathic/pseudomalignant and 37 patients (61.7%) with circumscribed. The mean age at diagnosis was 9.5 years (range 0.2-17 years), with a male-to-female ratio of 1:1. The initial pre-emptive diagnosis was neoplasia in 13 patients (21.7%). The biopsy was percutaneous in 9 patients (15%) and incisional in 7 patients (11.7%). Histological analysis was achieved in 35 cases (57%). Surgical excision was the first line treatment in 46.7% of patients, and non-surgical in the remaining patients. The follow-up strategy was clinical in 16 patients (26.7%) or based on imaging investigation in 23 patients (38.3%).

Discussion

Although MO in children is described as a rare pathology, identifying the benignity of the condition is essential to avoid unnecessary invasive treatment and to avoid delaying the treatment of a potentially life-threatening entity. It seems that there is no consensus established concerning the proper imaging for diagnosis. Clinicians should acknowledge that the absence of a triggering trauma tends to direct the investigation and the management toward a surgical attitude. Conservative management is key, however, surgical excision can be proposed on matured lesions on a case-by-case basis. The absence of recurrence is not excluded. Therefore, a close clinical follow-up is suggested for all cases. The true benefit of a radiological is questioned in a question known to be self-resolving.

Understanding a mass in the paraspinal region: an anatomical approach

The paraspinal region encompasses all tissues around the spine. The regional anatomy is complex and includes the paraspinal muscles, spinal nerves, sympathetic chains, Batson's venous plexus and a rich arterial network. A wide variety of pathologies can occur in the paraspinal region, originating either from paraspinal soft tissues or the vertebral column. The most common paraspinal benign neoplasms include lipomas, fibroblastic tumours and benign peripheral nerve sheath tumours. Tumour-like masses such as haematomas, extramedullary haematopoiesis or abscesses should be considered in patients with suggestive medical histories. Malignant neoplasms are less frequent than benign processes and include liposarcomas and undifferentiated sarcomas. Secondary and primary spinal tumours may present as midline expansile soft tissue masses invading the adjacent paraspinal region. Knowledge of the anatomy of the paraspinal region is of major importance since it allows understanding of the complex locoregional tumour spread that can occur via many adipose corridors, haematogenous pathways and direct contact. Paraspinal tumours can extend into other anatomical regions, such as the retroperitoneum, pleura, posterior mediastinum, intercostal space or extradural neural axis compartment. Imaging plays a crucial role in formulating a hypothesis regarding the aetiology of the mass and tumour staging, which informs preoperative planning. Understanding the complex relationship between the different elements and the imaging features of common paraspinal masses is fundamental to achieving a correct diagnosis and adequate patient management. This review gives an overview of the anatomy of the paraspinal region and describes imaging features of the main tumours and tumour-like lesions that occur in the region.

Intra-abdominal myositis ossificans - a clinically challenging disease: A case report

BACKGROUND

Myositis ossificans (MO) is an uncommon disorder characterized by heterotopic ossification within soft tissues. Only a few cases of intra-abdominal MO (IMO) have been described in the literature. Histology could be difficult to understand and a wrong diagnosis could lead to an improper cure.

CASE SUMMARY

We herein report the case of IMO in a healthy 69-year-old man. The patient presented with an abdominal mass in the left lower quadrant. A computed tomography scan showed an inhomogeneous mass with multiple calcifications. The patient underwent radical excision of the mass. Histopathological findings were compatible with MO. Five months later the patient showed a recurrence causing hemorrhagic shock due to intractable intralesional bleeding. The patients eventually died within three months since recurrence.

CONCLUSION

The case described could be classified as post-traumatic MO that developed close to the previously fractured iliac bone. The subsequent surgical procedure was ineffective and the disease rapidly recurred. The misleading intraoperative diagnosis led to improper surgical treatment with a dramatic evolution.

Imaging palpable tumors in pediatrics: Part 2

Palpable tumors in children are a common reason for consulting a radiologist. The origin of these lesions varies widely, and although they are common, classic radiology books do not cover some of them. This series of two articles aims to review the clinical and radiological characteristics of a selection of palpable tumors in children that radiologists need to be familiar with.

Aggressive atraumatic myositis ossificans in a toddler

Myositis ossificans (MO) is a benign disorder where bone forms within muscles or other soft tissues. This condition usually follows trauma and is rare in pediatric patients. Here we present the case of a 2-year-old male who developed MO of his right elbow without obvious trauma to the area. Imaging of MO in the initial phase is highly unspecific and obtaining tissue samples through a biopsy can render misleading reports. In most cases MO is a self-limited process with complete resolution, however, some cases may present a diagnostic and therapeutic challenge.

Traumatic Myositis Ossificans of Temporalis Muscle: Systematic Review, Meta-Analysis and Case Reports

Introduction

Traumatic myositis ossificans is rare pathology affecting muscles/soft tissue. Its involvement in temporalis muscle is rarely reported in literature. The aetiopathogenesis is unknown, the diagnosis is based on clinco-radiological findings. Surgical management and follow-up are paramount.

Materials and Methods

A database search was done using Science Direct and PubMed search engines along with other published and unpublished literature. The final publications were tabulated using a custom made Performa. The available publications were subjected to appropriate statistical analysis. The data were recorded on excel spreadsheet (Microsoft Inc), and review was made using Review Manager (Rev Man) software for meta-analysis.

Results

A total of 21 articles were considered for systemic review and meta-analysis. Forest plotting for demographics included the gender predilection/age of involvement. The data segregation was done with "temporalis involved" group and "other than temporalis involved" group. The study was free of homogeneity ( τ 2 = 0.26 I 2 = 5%) for gender and age. The overall analysis revealed that Temporalis muscle although rare to be affected shows greater propensity for involvement. This is supported by a lesser degree of heterogeneity ( τ 2 = 0.000) with a I 2 value of (The test showed a higher degree of significance for overall effect of muscle involvement (Z = 2.33, p = 0.02) (< 25%). The test showed a higher degree of significance for overall effect of muscle involvement (Z = 2.33, p = 0.02) (< α = 0.05).Case reports.Two male cases with similar age predilection, reported after sustaining trauma. Both the cases presented with limited mouth opening and ultrasound was done for the first time to arrive at clinic-radiological diagnosis. The management was conservative with temporalis myotomy and coronidectomy.

Conclusion

Traumatic myositis ossificans presents as a rare disorder that poses a dilemma to the treating surgeon. The present article makes an attempt to critically analyse the pathology that is scantly reported in the literature.