Various tumor-mimicking lesions in the musculoskeletal system: causes and diagnostic approach

A Rare Variation of the Levator Scapulae Muscle: A Case Report and Review of Literature

Muscle variations in the posterior neck region are mainly categorized as variations in the origin and insertion of the muscles and the presence of accessory slips or rudimentary muscles. The levator scapulae muscle is a variable muscle with several different types of variations described throughout the literature. Herein, we report a rare unilateral case of an accessory slip from the levator scapulae. Aberrant muscle slip originates from the distal one-third of the levator scapulae. Then, it passes upwards and outwards above a vascular bundle containing a superficial branch of the transverse cervical artery and vein. The deviant muscle slip inserts onto the superior nuchal line. Muscle variations in the neck's posterior region and the levator scapulae's variations, as per se, have the utmost clinical significance since they might be mistaken for tumor mass. Moreover, such variations might be deceptive during surgical procedures in the region. Therefore, detailed knowledge of such complex muscular variations in the posterior region of the neck is paramount for surgeons and radiologists alike.

Myotendinous pseudomasses: an imaging review

A mass or a tumor may not always be an underlying cause for a clinically apparent swelling. A wide range of myotendinous disorders can present as pseudomasses. These include muscle/myofascial hernia, tendon tears, benign hypertrophy, accessory muscles, tendon xanthomas, diffuse myositis, and exertional compartment syndromes. We have briefly reviewed these lesions highlighting their typical radiological findings and have also highlighted the role of different imaging modalities and the role of dynamic imaging. Although rare, radiologists should be aware of these entities to avoid mislabeling a pseudomass as a mass or malignancy and to detect the abnormality in not-so-apparent masses.

Previously undescribed variant muscle connecting longissimus and semispinalis capitis muscles

Thelongissimus capitis and the semispinalis capitis both function to bilaterally extend and unilaterally rotate the head. Typically, these muscles are distinct with origins and insertions at independent locations along the vertebral column. During a routine cadaveric dissection, an unusual muscle strip was identified between the longissimus capitis andsemispinalis capitismuscles on the left, posterior neck. This anatomical variation may have developed due to an incomplete or abnormal columnar segregation during gestation. The presence of this muscle strip contributes to previous case reports that have identified abnormal musculature between and along the longissimus and semispinalis muscles. Awareness of this muscular variant should be kept in mind by clinicians and surgeons who treat/operate this area of the body.

CT and MRI features of tumors and tumor-like lesions in the abdominal wall

Masses involving the abdominal wall are common in clinical practice and have many etiologies, including tumors and tumor-like lesions. Abdominal wall tumors include primary and secondary tumors, the former of which constitute a heterogeneous group of soft tissue tumors with their own unique spectrum. Tumor-like lesions, such as hernias, are more common and must be distinguished from true tumors. Medical imaging is valuable for discovering, diagnosing, and evaluating the extent of abdominal wall masses. With the increasing application of computed tomography (CT) and magnetic resonance imaging (MRI), determining a diagnosis or narrowing the differential diagnosis is often possible, thus facilitating effective management. In this article, we comprehensively review the spectrum of common abdominal wall masses and present the CT and MRI features of typical cases in our hospital. A systematic stepwise diagnostic approach is also proposed for clinical practice.

Distinguishing bone and soft tissue infections mimicking sarcomas requires multimodal multidisciplinary team assessment

INTRODUCTION

The aims of this study were to report the presenting characteristics and identify how best to distinguish bone and soft-tissue infections that mimic sarcomas.

MATERIALS AND METHODS

A total of 238 (211 osteomyelitis and 27 soft-tissue infections) patients referred to a tertiary sarcoma multidisciplinary team with suspected sarcoma who were ultimately diagnosed with a bone or soft tissue infection were included. Data from a prospectively collated database was analysed retrospectively.

RESULTS

Of all possible bone and soft-tissue sarcoma referrals, a diagnosis of infection was made in 2.1% and 0.7%, respectively. Median age was 18 years in the osteomyelitis group and 46 years in the soft-tissue infection group. In the osteomyelitis group, the most common presenting features were pain (85.8%) and swelling (32.7%). In the soft-tissue infection group, the most common clinical features were swelling (96.3%) and pain (70.4%). Those in the soft-tissue group were more likely to have raised inflammatory markers. Radiological investigations were unable to discern between tumour or infection in 59.7% of osteomyelitis and 81.5% of soft-tissue infection cases. No organism was identified in 64.9% of those who had a percutaneous biopsy culture.

CONCLUSIONS

This study has highlighted that infection is frequently clinically indistinguishable from sarcoma and remains a principle non-neoplastic differential diagnosis. When patients are investigated for suspected sarcoma, infections can be missed due to falsely negative radiological investigations and percutaneous biopsy. As no single clinical, biochemical or radiological feature or investigation can be relied upon for diagnosis, clinicians should have a low threshold for tissue biopsy and discussion in a sarcoma multidisciplinary team meeting.

Ossified soft tissue recurrence of giant cell tumor of the bone: four case reports with follow-up radiographs, CT, ultrasound, and MR images

Giant cell tumor (GCT) of the bone is a benign tumor with a high incidence of recurrence. The majority of recurrence occurs in the bone, typically where curettage was performed previously. Soft tissue recurrence is much less common and often shows ossification at the periphery of the soft tissue mass. We report four cases of ossified soft tissue recurrence of giant cell tumor of the bone after surgery at follow-up examination using plain radiography, ultrasound, CT, and MR imagings. Imaging findings of soft tissue recurrence with peripheral or central ossification were reviewed with pathologic correlation. To the best of our knowledge, this is the first report to describe soft tissue tumor recurrence with ossification illustrated and monitored at various imaging modalities over an extended follow-up period.