Musculoskeletal neoplasia: helping the orthopaedic surgeon establish the diagnosis

Encountering musculoskeletal neoplasia in the clinical practice of orthopaedic surgery is a rather uncommon event but can be an anxiety-provoking experience when it occurs. Using a systematic approach to imaging these lesions includes evaluation via plain radiographs and other modalities such as bone scintigraphy (BS), computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). By applying specific imaging characteristics obtained from these different modalities, the radiologist and orthopaedic surgeon can jointly create an appropriate differential diagnosis. The radiologist plays a key role as part of the diagnostic team, including providing crucial support for biopsy and staging. This article discusses a systematic approach in the evaluation and staging of musculoskeletal neoplasia from the perspective of supporting the orthopaedic surgeon.     

The importance of radiographic imaging in the microscopic assessment of bone tumors

Introduction

Primary bone tumors are rare and require a multidisciplinary approach. Diagnosis involves primarily the radiologist and the pathologist. Bone lesions are often heterogeneous and the microscopic diagnostic component(s) may be in the minority, especially on core needle biopsies. Reactive processes, benign, and malignant tumors may have similar microscopic aspects. For these challenging cases, the correlation of microscopic and radiologic information is critical, or diagnostic mistakes may be made with severe clinical consequences for the patient. The purpose of this article is to explain how pathologists can best use imaging studies to improve the diagnostic accuracy of bone lesions.

Diagnosis

Many bone lesions are microscopically and/or radiographically heterogeneous, especially those with both lytic and matrix components. Final diagnosis may require specific microscopic diagnostic features that may be present in the lesion, but not the biopsy specimen. A review of the imaging helps assess if sampling was adequate. The existence of a pre-existing bone lesion, syndrome (such as Ollier disease or multiple hereditary exostosis), or oncologic history may be of crucial importance. Finally, imaging information is very useful for the pathologist to perform accurate local and regional staging during gross examination.

Conclusion

Close teamwork between pathologists, radiologists, and clinicians is of utmost importance in the evaluation and management of bone tumors. These lesions can be very difficult to interpret microscopically; imaging studies therefore play a crucial role in their accurate diagnosis.     

MR imaging of tumor and tumorlike lesions of bone and soft tissue

This review examines the role of MR imaging in the diagnosis and staging of tumors and tumorlike lesions of bone and soft tissue. For tumors of bone, the plain radiograph is not only the least expensive diagnostic test but is the most reliable predictor of the histologic nature of a given lesion. Consequently, it should be the first procedure performed and serve as the basis for determining the next step in the patient's evaluation. MR imaging is the examination of choice for staging bone tumors. CT is preferred to MR imaging only when the characteristics of the lesion are inadequately defined on plain radiographs, as may occur in flat bones. Although MR imaging is of limited value in predicting the histology of bone tumors, it is a useful tool for distinguishing round-cell tumors and metastases from stress fractures and medullary infarcts in symptomatic patients with normal radiographs. For depiction of soft-tissue masses, MR imaging is unrivaled. The histologic nature of a soft-tissue mass may, in some instances, be predicted on the basis of its MR appearance and multicentricity. Biopsy of bone and soft-tissue tumors should follow and not precede MR imaging. MR imaging reliably shows change in tumor volume after radiation or chemotherapy. It is less reliable in predicting the amount of tumor necrosis.     

Staging of bone tumors: a review with illustrative examples

OBJECTIVE: The radiologist plays an important role in the workup and staging of bone tumors. The purpose of this article is to review that role and to discuss recent changes to the primary malignant bone tumor staging system developed by the American Joint Committee on Cancer. CONCLUSION: Knowledge of staging parameters for the diagnosis and management of bone tumors will help the radiologist to generate meaningful reports for the referring physician.     

Cerebral neoplasms in adults

MRI plays a critical role in the diagnosis, management, and follow-up of adult supratentorial neoplasms. However, there is considerable overlap in the imaging findings of these lesions. New imaging methods, such as functional MRI, diffusion imaging, and spectroscopy may further improve diagnostic specificity and surgical management. Knowledge of the pathogenesis of these tumors, imaging characteristics, and available novel imaging tools will aid the radiologist in making meaningful contributions in the evaluation and treatment of these lesions.     

Uncommon tumors and pseudotumoral lesions of the pancreas

Ductal adenocarcinoma is the most common tumor of the pancreas, accounting for about 80% of all pancreatic tumors. The other 20% of pancreatic tumors is represented by a heterogeneous group of pancreatic neoplasms that includes cystic pancreatic neoplasms, islet cell tumors, and the so-called rare pancreatic tumors. In addition, the pancreatic gland may present a variety of inflammatory and pseudotumoral lesions that may mimic a primary pancreatic neoplasm. These uncommon tumors and pseudotumoral lesions present a wide spectrum of imaging findings and they are often poorly understood by the radiologist, becoming a diagnostic challenge. Some of these lesions may show an appearance similar to ductal adenocarcinoma being radiologically indistinguishable. However, some of these lesions sometimes may present specific features on imaging studies that may help to characterize the mass and to suggest a correct diagnosis. Many of these uncommon tumors and pseudotumoral lesions have a different approach, therapy, and prognosis than ductal adenocarcinoma. Therefore, it is important for the radiologist to be familiar with these entities to include them in the differential diagnosis to initiate an appropriate lesion-specific workup and treatment. In the present article, we review the radiological features of uncommon pancreatic tumors, atypical manifestations of ductal adenocarcinoma, and pseudotumoral masses, focusing on those features that can be helpful for the differential diagnosis.     

Primary non-odontogenic tumors of the jawbones: an overview of essential radiographic findings

The jawbones, namely the maxilla and mandible, can be the sites of a multitude of neoplastic conditions. Given the variety of processes affecting this particular anatomic area, formulation of a precise diagnosis often can be challenging to the radiologist and the clinician, who may not be familiar with the imaging findings fundamental to diagnosis. Although advanced imaging methods have been developed, routine radiography remains the mainstay in the initial assessment of osseous lesions involving the jawbones. We review and summarize the imaging appearances of non-odontogenic tumors of the jawbones and illustrate example cases of these uncommon neoplasms of bone. Detailed patient history, physical examination, laboratory evaluation and histopathologic analysis are of paramount importance in diagnostic approach and, in most cases, are to be considered in the imaging evaluation of a given lesion. Correct interpretation of the imaging features of lesions involving the jawbones suggests the diagnosis, aids in presurgical planning and improves patient management.     

Imaging of bone tumors for the musculoskeletal oncologic surgeon

The appropriate diagnosis and treatment of bone tumors requires close collaboration between different medical specialists. Imaging plays a key role throughout the process. Radiographic detection of a bone tumor is usually not challenging. Accurate diagnosis is often possible from physical examination, history, and standard radiographs. The location of the lesion in the bone and the skeleton, its size and margins, the presence and type of periosteal reaction, and any mineralization all help determine diagnosis. Other imaging modalities contribute to the formation of a diagnosis but are more critical for staging, evaluation of response to treatment, surgical planning, and follow-up.When necessary, biopsy is often radioguided, and should be performed in consultation with the surgeon performing the definitive operative procedure. CT is optimal for characterization of the bone involvement and for evaluation of pulmonary metastases. MRI is highly accurate in determining the intraosseous extent of tumor and for assessing soft tissue, joint, and vascular involvement. FDG-PET imaging is becoming increasingly useful for the staging of tumors, assessing response to neoadjuvant treatment, and detecting relapses.Refinement of these and other imaging modalities and the development of new technologies such as image fusion for computer-navigated bone tumor surgery will help surgeons produce a detailed and reliable preoperative plan, especially in challenging sites such as the pelvis and spine.     

Magnetic resonance imaging of musculoskeletal tumors: skeletal and soft tissue masses

The purpose of this article is to review the MRI characteristics of musculoskeletal tumors, including skeletal and soft tissue masses. MRI has become the premier imaging modality for the evaluation of musculoskeletal tumors because of its excellent soft tissue contrast, its sensitivity to bone marrow and soft tissue edema, and its multiple imaging planes. In a substantial subset of cases, MRI can provide a diagnosis or a short differential diagnosis, while certain tumors have no distinguishing signal characteristics. MRI of musculoskeletal tumors can also be challenging, because the MRI appearance of certain lesions can be misleading, and a knowledge of the instances in which MRI over- and underestimates the malignancy of lesions is invaluable. The importance of correct protocols for tumor evaluation, both in diagnosis and in pre-operative evaluation, are discussed. Common pitfalls that may over- or underestimate the aggresivity of lesions will be highlighted, as will the role of gadolinium enhancement in the evaluation of lesions. The MRI appearance of common benign and malignant muculoskeletal lesions will be illustrated.     

Endocrine tumors of the pancreas

We have described the clinical presentation of the commonest syndromes associated with hormone production by functioning pancreatic tumors. The role of the radiologist in tumor localization, staging, and treatment is discussed and the various imaging methods employed are examined individually. The problems of reviewing the world literature on such rare lesions are discussed and a tentative diagnostic algorithm is suggested.     

Imaging of urothelial cancers: what the urologist needs to know

OBJECTIVE: Imaging is vital in the diagnosis, staging, and surveillance of urothelial carcinomas. In this review, we discuss what treating urologists need to know from radiologists to optimally identify disease, plan surgery, determine prognosis, and identify patients in need of multimodal or alternative treatment strategies. We identify key points that a radiologist should convey to the treating urologist, in writing, in order to be an active partner in the formulation of an effective course of care. CONCLUSION: Because imaging plays a crucial role in the diagnosis, staging, and surveillance of patients with tumors of the urinary tract, it is imperative that radiologists provide information about the anatomic features related to the primary tumor, the surrounding anatomy, and involvement or lack of involvement of known potential landing sites for metastases. A good understanding of the imaging features that affect management of the disease and a good relationship between the radiologist and the urologist are vital to the care of patients with urothelial cancers.     

Diagnosis and staging of laryngeal tumors with CT and MRI

Summary Cross-sectional imaging with CT and MRI plays an indispensable complementary role to endoscopy in the pretherapeutic workup and staging of laryngeal neoplasms. Adequate interpretation of the CT and MR images requires a thorough knowledge of the patterns of submucosal spread and familiarity with the diagnostic signs of neoplastic invasion as seen with each modality. In addition, the radiologist should be aware of the implications of imaging for staging and treatment. Both CT and MR imaging are highly sensitive for the detection of neoplastic invasion of the pre-epiglottic space, paraglottic space, subglottic region and cartilage. The high negative predictive value of both CT and MRI allows exclusion of neoplastic cartilage invasion quite reliably. The specificity of both CT and MRI is, however, limited and both methods may therefore overestimate the extent of tumor spread. Nevertheless, both cross-sectional imaging methods significantly improve the pretherapeutic staging accuracy of laryngeal tumors if used in addition to clinical examination and endoscopic biopsy. In the presence of a submucosal mass, CT and MRI play a key role for the diagnosis, as they may characterize the lesion, reliably depict its submucosal extent, and guide the endoscopist to perform deep biopsies that allow a definitive histological diagnosis.      

Maligne Lungentumoren im Kindesalter

Pulmonary neoplasms in children are rare. The majority of tumors involving the respiratory system are metastatic and primary lung tumors are even more rare. Approximately 75% of primary lung tumors are malignant, the most frequent of which are adenoma, bronchogenic carcinoma, and pleuropulmonary blastoma. Due to the rarity of these malignancies, and the usually nonspecific clinical symptoms, they are often not considered in the differential diagnosis in children who present with persistent pneumonitis, coughing, and atelectasis. This often results in delayed definitive treatment and, in general, a worse prognosis. The role of the radiologist is that by using modern imaging techniques, to facilitate early recognition and staging, enabling adequate treatment and follow-up and thus, a better clinical prognosis. This article provides an overview of the most relevant entities of primary childhood pulmonary malignancies, with a particular emphasis on the imaging characteristics.     

Bone tumor mimics: avoiding misdiagnosis

Whether discovered incidentally or as part of a focused diagnostic evaluation, the finding of a benign osseous lesion that has radiologic features resembling a bone tumor is not uncommon. Some of the more common benign and nonneoplastic entities that can sometimes be confused with tumors are the following: cortical desmoid, Brodie abscess, synovial herniation pit, pseudocyst, enostosis, intraosseous ganglion cyst, fibrous dysplasia, stress fracture, avulsion fracture (healing stage), bone infarct, myositis ossificans, brown tumor, and subchondral cyst. Accurate diagnosis and management of these lesions require a basic understanding of their epidemiology, clinical presentations, anatomic distributions, imaging features, differential considerations, and therapeutic options. This in-depth review of 13 potential bone tumor mimics will assist the radiologist in correctly identifying these benign lesions and in avoiding misdiagnosis and related morbidity. This review will also aid the radiologist in making appropriate recommendations to the referring physician for management or further imaging.     

Upper extremity compartmental anatomy: clinical relevance to radiologists

Malignant tumors of the upper extremity are uncommon, and their care should be referred to specialized facilities with experience treating these lesions. The Musculoskeletal Tumor Society (MSTS) staging system is used by the surgeon to determine appropriate surgical management, assess prognosis, and communicate with other healthcare providers. Magnetic resonance imaging (MRI) is employed pre-operatively to identify a lesion’s compartment of origin, determine extent of spread, and plan biopsy and resection approaches. Involvement of neurovascular structures may result in devastating loss of upper extremity function, requiring amputation. Violation of high-resistance compartmental barriers necessitates more extensive surgical resection. Biopsy may be performed by the radiologist using imaging guidance. Knowledge of compartmental anatomy allows the radiologist or surgeon to use an easily excisable biopsy approach and prevent iatrogenic spread to unaffected compartments. Case examples are presented to illustrate the importance of compartmental anatomy in the management of benign and malignant upper extremity tumors.     

Gastrointestinal tumors in children

Although tumors arising from the spleen, pancreas, and gastrointestinal tract in the pediatric population are relatively uncommon, imaging plays an important role in diagnosis, staging, and treatment planning. Initial imaging with abdominal radiograph contributes to the evaluation for intestinal obstruction, constipation, and mass effect, and sometimes may reveal areas of calcification.     

颅内间变性血管外皮细胞瘤伴骨转移一例

笔者报道了1例颅内间变性血管外皮细胞瘤（AHPC）伴骨转移的病例,从临床表现、影像学检查尤其是全身骨显像检查以及术后病理综合分析了该病特点。并通过文献复习加深了对AHPC骨转移的认识。多数恶性肿瘤常见骨转移,而颅内AHPC是一种少见的中枢神经系统肿瘤,较少发生骨转移。通过全身骨显像发现了该例患者多处骨骼病变,术后病理提示颅内AHPC骨转移,因此提示恶性肿瘤尤其是少见骨转移者应把骨显像检查作为随访的一个重要检查,对于早期发现骨转移、确定临床分期及治疗方案的选择等都是至关重要的。     

Benign breast lesions detected by positron emission tomography-computed tomography

¹⁸F-fluorodeoxyglucose positron emission computed tomography (FDG PET-CT) is widely used in the initial staging and response evaluation of patients with malignancy. This review describes a spectrum of benign breast findings incidentally detected by FDG PET-CT at staging that may be misinterpreted as malignancy. We describe the pattern of distribution and intensity of FDG uptake in a spectrum of benign breast diseases with their corresponding typical morphological imaging characteristics to help the nuclear medicine physician and/or general radiologist identify benign lesions, avoiding unnecessary breast imaging work-up and biopsies.     

State-of-the-art cross-sectional imaging in bladder cancer

Advances in cross-sectional imaging have given radiology an increasingly significant role in the diagnosis, staging, and restaging of patients with bladder cancer. The primary role of computed tomography (CT) in bladder cancer is for tumor staging and screening for distant metastases. Multidetector-row CT may improve the evaluation of bladder tumors by overcoming the difficulties of previous generations of CT in detecting invasion of contiguous organs and nodal staging. Magnetic resonance imaging (MRI) however is still considered superior to CT for primary staging of bladder carcinoma. The multiplanar capability of MRI with its superior soft-tissue resolution offers improved evaluation of local staging of bladder tumors. Positron emission tomography/CT is emerging as a novel-imaging tool for the detection of distant metastases. In this review, we emphasize the value of current cross-sectional imaging and discuss the potential applications of novel imaging techniques in the management of patients with bladder cancer, predominantly transitional cell carcinoma.     

Bone scintigraphy in the initial staging of patients with renal-cell carcinoma: concise communication

We reviewed the records of 40 consecutive patients who received bone scintigraphy in conjunction with the initial evaluation and staging of renal-cell carcinoma, to determine the role of bone imaging in this clinical context. Bone scintigrams were positive in three out of 40 patients at the time of diagnosis. In view of the low yield of bone imaging, it appears that routine scintigraphy is unwarranted in the absence of skeletal symptoms before the diagnosis of renal lesions. The presence of a positive bone image did not alter the indication for nephrectomy.