The appropriate and sequential value of standard radiograph, computed tomography and magnetic resonance imaging to characterize a bone tumor.

Radiographs (XR), computed tomography (CT) or magnetic resonance imaging (MRI) are regularly analyzed to determine whether a bone lesion is benign or malignant. An online quiz was created providing 15 cases with a clinical summary, MRI, CT, and XR. After each image, participants were asked to rate the probability (0-100%) the bone tumor was malignant. Order and difficulty of the images were randomly determined. Probability statements regarding the diagnosis were actualized along the sequence of exam, to quantify how the degree of belief changed to account for evidence from those exams. 64 physicians participated and provided 154 assessments from 1 (n = 18) to 3 (n = 44) different cases. After the first image, participants favored the correct malignancy status at 70%; 80% after the second and 80% after the third one. Participants were more likely to favor the correct malignancy status when the lesion was malignant and when first confronted with XR or CT, rather than MRI, though the most predictive factor of correct diagnosis was the difficulty of the case. In conclusion, the additional information provided by successive imaging studies was moderate. XR or CT seemed more appropriate than MRI as first imaging study. Bypassing XR should be discouraged.

Intramedullary, periosteal, and extraskeletal Ewing sarcomas: retrospective study of a series of 126 cases in a reference center.

OBJECTIVE: To evaluate the proportion of extraskeletal, periosteal, and intramedullary Ewing sarcomas among musculoskeletal Ewing sarcomas. MATERIAL AND METHOD: Our single-center retrospective study included patients with musculoskeletal Ewing sarcoma diagnosed between 2005 and 2019 in our pathology center (cases from our adult bone tumor referral center and adult and pediatric cases referred for review). Recurrences, metastases, and visceral Ewing sarcomas were excluded. Intramedullary Ewing sarcomas were defined by involvement of the medullary cavity. Periosteal cases were defined by involvement of the subperiosteal area without extension to the medullary cavity. Extraskeletal cases were defined by the absence of involvement of the bone tissue and the subperiosteal area. RESULTS: Our series included 126 patients with musculoskeletal Ewing sarcoma, including 118 skeletal Ewing sarcomas (93.7%) and 8 extraskeletal Ewing sarcomas (6.3%). Of the 118 skeletal Ewing sarcomas 112 were intramedullary (88.9%) and 6 were periosteal (4.8%). Extraskeletal Ewing sarcomas were more common in women and in patients older than 40 (p < 0.05). DISCUSSION: The 6.3% proportion of extraskeletal Ewing sarcoma is lower than the median of 30% estimated from the literature. This difference could be explained by an overestimation of extraskeletal Ewing sarcomas of the chest wall (Askin tumors), an underestimation of periosteal cases confused with extraskeletal cases, and the presence of "Ewing-like" soft tissue sarcomas in previous series. Because of its prognostic and therapeutic impact, the distinction of morphologic subtypes requires the cooperation of experienced radiologists and pathologists.

Protuberant fibro-osseous lesion of the temporal bone: report of four cases and review of the literature.

'Bullough lesions', also referred to as protuberant fibro-osseous lesions (PFOL), are rare temporal bone lesions initially described in 1999. Since only 12 cases have been reported, several key issues, such as their origin and recommended management strategies, remain unresolved. This article reports the largest cohort included in the literature to date, comprising four patients with PFOL. PFOL appears to be characterized by female and right-side predominance. These lesions were consistently located regarding the mastoid, generally diagnosed in early adulthood, without functional symptoms, and were always fibro-osseous. Invasive/malignant features were not found on imaging or histology. The main differential diagnosis was malignant low-grade parosteal osteosarcoma. Clinical examination and computed tomography images provided strong elements supporting the diagnosis of PFOL. Biopsy allowed molecular biology investigations (MDM2 and CDK4 amplification), in order to rule out low-grade parosteal osteosarcoma.

Parosteal osteosarcoma associated with a low-grade component mimicking well-differentiated liposarcoma: a case report.

Parosteal osteosarcomas and well-differentiated liposarcomas are both well-differentiated locally aggressive tumors. They both have simple karyotypes with amplification of the 12q13-15 regions including MDM2 and CDK4 genes. In this report, we describe the case of a parosteal osteosarcoma intertwined with a low-grade component similar to a well-differentiated liposarcoma. The association of a bone component with an adipose component was initially overlooked. We describe the histological, imaging, and molecular characteristics of this tumor stressing the importance of radio-pathological correlation. To our knowledge, this is the second report of a parosteal osteoliposarcoma. Awareness of this rare presentation may allow radiologists and surgeons to recognize the peripheral fatty component as an integral part of the tumor.

An odd and serious "disc bulging"!

BACKGROUND AND IMPORTANCE: Cauda equina syndrome is a common acute medical condition, usually caused by large degenerative disc herniation or metastatic lumbar disease. We describe a patient who presented with a lesion featuring both discal and tumoral characteristics. CLINICAL PRESENTATION: A 41-year-old woman presented with ongoing back pain, progressive lower-limb weakness and sphincter disorder. Magnetic resonance imaging showed a very odd-looking large anterior epidural lesion originating from the L3-L4 space and severely compressing the roots of the cauda equina. Partial surgical decompression was performed in emergency. At a later time, redo surgery was performed to maximize resection, and was unfortunately followed by several complications. After 6 surgical procedures including a ventriculo-peritoneal shunt insertion and intensive rehabilitation, the patient could walk independently with the aid of one crutch. Following collegial review, the diagnosis of low-grade chondrosarcoma of the intervertebral disc was suggested. CONCLUSION: We report on a very unusual and therapeutically challenging spinal tumor diagnosed as low-grade chondrosarcoma of discal origin, an entity never previously described.

Proximal femoral osteosarcoma: Diagnostic challenges translate into delayed and inappropriate management.

BACKGROUND: The proximal femuris is an uncommon site of osteosarcoma. The unusual manifestations at this site may lead to diagnostic and therapeutic mistakes. We therefore performed a retrospective study to estimate the proportions of patients with imaging study findings and/or clinical manifestations typical for osteosarcoma and/or inappropriate treatment decisions. HYPOTHESIS: Proximal femoral osteosarcoma often produces atypical clinical and radiological presentations. MATERIAL AND METHODS: Consecutive patients who underwent surgery at our center to treat proximal femoral osteosarcoma were included. For each patient, we collected the epidemiological characteristics, clinical symptoms, imaging study findings, treatment, and tumor outcome. Proportions were computed with their confidence intervals. RESULTS: Twelve patients had surgery for proximal femoral osteosarcoma between 1986 and 2015. Imaging findings were typical in 1 (8%) patient; they consisted of ill-defined osteolysis in 11/12 (92%) patients, a periosteal reaction in 1/12 (8%) patient, soft tissue involvement in 7/12 (58%) patients, and immature osteoid matrix in 11/12 (92%) patients. No patient had the typical combination of pain with a soft tissue swelling. Management was inappropriate in 2/12 (17%) patients, who did not undergo all the recommended imaging studies before surgery and were treated in another center before the correct diagnosis was established. At last follow-up, 4 patients had died (after a mean of 7 years) and 8 were alive (after a mean of 4 years). CONCLUSION: Proximal femoral osteosarcoma is uncommon and rarely produces the typical clinical and imaging study findings. The atypical presentation often results in diagnostic errors and inappropriate treatments. Ill-defined osteolysis on standard radiographs should prompt computed tomography or magnetic resonance imaging of the proximal femur. Treatment in a specialized center is imperative. LEVEL OF EVIDENCE: IV, retrospective study.

Therapeutic outcome of CT-guided radiofrequency ablation in patients with osteoid osteoma.

OBJECTIVE: To assess the long-term outcome of computed tomography-guided radiofrequency ablation (CT-guided RFA) in patients with suspected osteoid osteoma (OO). MATERIALS AND METHODS: Single-center retrospective study. Patients with clinical suspicion and imaging diagnosis of osteoid osteoma were treated by CT-guided RFA using the same device with either a 7- or 10-mm active tip electrode. Specific precautions were applied in case of articular or spinal OO. Patients were contacted by phone to evaluate the long-term outcome in terms of pain, ability to perform daily activities (including sports), and long-term complications. Success was defined as the absence of residual pain and ability to perform daily activities normally. RESULTS: From 2008 to 2015, 126 patients were treated by CT-guided RFA for OO in our institution. Mean patient age was 26.1 years (SD = 11, range 1-53); mean delay to diagnosis was 16.9 months (SD = 15.2, range 1-120). Among patients who answered the follow-up call (n = 88), the overall success rate was 94.3%: 79/88 (89.8%) had primary success of the procedure, and 4/88 (4.5%) had a secondary success (repeat-RFA after pain recurrence). Mean follow-up time was 34.6 months (SD = 24.7, range 3-90). Few complications occurred: two mild reversible peripheral nerve injuries, one brachial plexus neuropathy, one broken electrode tip fragment, and one muscular hematoma. CONCLUSION: Osteoid osteoma can be effectively and safely treated by CT-guided RFA using the presented ablation protocol. Beneficial effects of the treatment persist at long-term follow-up.

Dedifferentiated primary mediastinal liposarcoma mimicking a thymic tumor.

Mediastinal tumors are heterogeneous and the diagnosis depends on their location in the mediastinum. The most frequent tumors are germinal tumor, lymphoma and thymoma. The clinical and radiological aspects are often not sufficient to orient the diagnosis and biopsy is necessary to confirmed it. Here, we present a rare case of an anterior mediastinal mass incidentally detected in a 63 years old man during assessment for asthma. The lesion was presumptively diagnosed as a thymic epithelial tumor based on location and radiological characteristics. Surgical biopsy revealed a primary dedifferentiated mediastinal liposarcoma with multiple lung metastases.

Ultrasound of wrist and hand masses.

Ultrasound is a useful tool to investigate soft tissue masses in the wrist and hand. In most situations ultrasound helps distinguish between a cyst and a tissue mass. This article provides a simple clinical approach to the use of ultrasound imaging for the diagnosis and preoperative assessment of wrist and hand masses.

Superficial myxofibrosarcoma: assessment of recurrence risk according to the surgical margin following resection. A series of 21 patients.

INTRODUCTION: Superficial myxofibrosarcomas are malignant connective tissue tumors, whose very frequent recurrence influences the local and vital prognosis. Even when resection seems to be macroscopically complete it is very often microscopically contaminated. The aim of this study was to evaluate recurrence in relation to the surgical margins and to compare, when possible, tumor size, evaluated clinically and macroscopically by the pathologist. MATERIALS AND METHODS: This was a single center study of 21 patients, mean age 67 years old, treated for superficial myxofibrosarcoma. The number, date and location of recurrence were collected for each patient. A clinical and pathological measurement was made of the longest axis of the tumor in each case of recurrence. RESULTS: Fifty-seven percent of patients presented with recurrent tumors. The mean number of recurrences was 1.4 per patient (1-8). The surgical margins were wide in four cases, marginal in two cases and incomplete/intralesional in 15 other patients with a rate of recurrence of 25, 50 and 67% respectively. The size evaluated during the preoperative clinical examination (14 cases) was underestimated by a mean 2.4 cm compared to the macroscopic pathology assessment. The preoperative size on MRI (5 cases) was also underestimated by a mean 1.3 cm. CONCLUSION: Superficial myxofibrosarcomas are tumors that are difficult to resect completely because they are infiltrative, a feature that is often underestimated before surgery. Surgical treatment of this entity requires a much larger surgical margin than that suggested by the preoperative clinical and MRI evaluations. In case of incomplete resection, revision scar surgery should systematically be performed. LEVEL OF EVIDENCE: Level IV. Retrospective study.

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.

Parosteal osteoliposarcoma: a new bone tumor (from imaging to immunophenotype).

INTRODUCTION: Parosteal osteosarcomas and well-differentiated liposarcomas (WDLPS) of soft tissue share several features: they are slowly progressive, locally aggressive tumors, tend to recur locally, and rarely or never metastasizes if not dedifferentiated. Their treatment is wide surgical resection. Microscopically, both are well differentiated tumors, very like their normal tissue counterpart. They share simple karyotypes with supernumerary ring chromosomes or giant marker chromosomes containing amplified 12q sequences including MDM2 and CDK4 genes, with subsequent overexpression of MDM2 and CDK4 proteins. We present the case of a parosteal osteoliposarcoma made of closely intermingled components of a low-grade osteosarcoma and a WDLPS. CASE: In a 34 year-old woman with a slowly growing mass of the arm, imaging revealed a large well-defined heterogeneous parosteal mass of the upper humerus, with two main components: bone at the base and fat at the periphery. Microscopically, these two components were consistent respectively with low grade osteosarcoma and WDLPS. Cells of the two components were labeled with anti-CDK4 antibody. No labeling with anti-MDM2 antibody and no signal detected with MDM2 FISH analysis were likely due overdecalcification. No frozen tumor tissue was available for FISH analysis nor array-CGH. DISCUSSION: Differential diagnoses of this new entity would be a well-differentiated liposarcoma with a low-grade osteosarcomatous component that originates from the soft tissues, ruled out on imaging, and an ossifying parosteal lipoma, ruled out on immunohistochemistry. CONCLUSION: This is the first description of a low-grade parosteal sarcoma with two components that morphologically and immunophenotypically demonstrate characteristics of a parosteal osteosarcoma and of a well-differentiated liposarcoma.

Usefulness of routine intraoperative staging of suspicious adnexal tumours: illustration by two cases of adult granulosa cell tumour.

Granulosa cell tumours (GCTs) account for less than 3% of all ovarian malignancies but are among the most common sex cord-stromal tumours. They may develop at any age. Symptoms related to oestrogen production by the tumour may occur. Because GCTs are uncommon and cannot be diagnosed preoperatively, their management is challenging. Surgery with salpingo-oophorectomy and painstaking staging is mandatory. Adjuvant chemotherapy is required in some patients. We report two cases of adult GCTs that illustrate the usefulness of extensive abdominal exploration in every patient with a suspicious ovarian mass, to obviate the need for a second staging procedure. With this strategy, the prognosis is excellent, although the possibility of late recurrences requires prolonged follow-up.

[Dedifferentiated chondrosarcoma: radiologic-pathologic correlation]. / Chondrosarcomes dédifférenciés: revue iconographique radio-pathologique.

Dedifferentiated chondrosarcomas are highly malignant tumors characterized by conventional low-grade chondrosarcoma with abrupt transition to foci that have dedifferentiated into a higher-grade noncartilaginous more aggressive sarcoma. The dedifferentiated component, an osteosarcoma or fibrosarcoma, determines the prognosis. Its identification is key for management. A diagnosis of dedifferentiated chondrosarcoma should be suggested by the presence of "tumoral dimorphism" with cartilaginous component and aggressive lytic component invading adjacent soft tissues.