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Background: In patients with relapsed osteosarcoma, the surgical excision of all metastases, defined as second complete remission (CR-2), is the factor that mainly influences post-relapse survival (PRS). Currently a validated follow-up policy for osteosarcoma is not available, both chest X-ray and computed tomography (CT) are suggested for lung surveillance. The purpose of this study is to evaluate whether the type of imaging technique used for chest surveillance, chest X-ray or CT, influenced the rate of CR-2 and prognosis in patients with recurrent osteosarcoma., Methods: Patients up to 40 years with extremity osteosarcoma enrolled in consecutive clinical trials and treated at the Rizzoli Institute from 1986 to 2009 were identified. Only patients who had lung metastases alone as first pattern of recurrence were considered for the analysis. The rate of CR-2, overall survival (OS) and PRS were the end-points of the study., Results: The median follow-up was 47 months (1-300), 215 patients were eligible. Lung metastases were detected by chest X-ray in 100 (47%) patients, by CT in 112 (52%) and by symptoms in 3 (1%). CR-2 rate was 60% for patients followed by X-rays and 88% for those followed by CT (p < .0001). 5-year PRS was 30% (95% CI 21-39) in the X-ray group and 49% (95% CI 39-59) in the CT group (p = .0004). 5-year OS was 35% (95% CI 26-44) in the X-ray group and 60% (95% CI 51-70) in the CT group (p = .004)., Conclusions: A follow-up strategy with chest CT leads to a higher rate of CR-2 and significantly improves PRS and OS in osteosarcoma, compared to chest X-ray.

Purpose: To describe the imaging features of soft tissue solitary fibrous tumors, with histopathological correlations and clinical outcome., Material and Methods: Twenty-seven patients with histologically proven SFTs were retrospectively evaluated. Imaging studies included six radiographs, five U/S studies, eighteen CT scans, fourteen MRI exams, and one angiography., Results: On CT scans, two lesions were isodense and five were mildly hypodense compared to muscle while 11 lesions appeared heterogeneous-mixed of iso and hypodense areas. Heterogeneous enhancement was depicted in 13 lesions and four lesions enhanced homogeneously. Six lesions were partially calcified. On T1W MR images, seven lesions were isointense and one was slightly hyperintense relative to adjacent muscles while five lesions appeared heterogeneous-mixed of iso and hypointense areas. T2W images showed high SI in two cases and heterogeneous-mixed in seven cases. Enhancement was heterogeneous in six and homogeneous in four lesions. Patchy unenhanced areas (on CT and T1W MR images) along with patchy areas of low to markedly high SI on T2W images were depicted in 19 lesions. The enhanced portions correlated to areas of increased vascularity and cellularity. The four clinically more aggressive lesions could not be predicted on imaging., Conclusion: Typical soft tissue SFTs are deep masses made of isodense and isointense areas relative to adjacent muscles mixed with hypodense and hypointense areas on unenhanced CT and MR T1W respectively. Variable enhancement patterns and mixed to high signal intensities on MRT2W are attributed to tumor's cellularity, vascularity, collagen distribution and/or degeneration. Heterogeneity of SFTs affects imaging features on MRI and CT modalities. The biological behavior of soft tissue SFTs can not be predicted based solely either on histopathologic or imaging evaluation.

A 35-year-old female presented with pain and swelling of the left wrist. A diagnosis of Ewing sarcoma was made and she underwent neoadjuvant chemotherapy and surgery. Macroscopic viable areas remained on the map of the surgical specimen; as such, she was classified as a poor responder and received high dose adjuvant chemotherapy. She remained disease-free for five years, until age 40. A vaginal polyp was then detected during a routine gynaecologic examination. It was removed and histopathology revealed metastatic Ewing sarcoma. To our knowledge, this is the first reported case of a vaginal metastasis of Ewing sarcoma.

Background: To analyze the imaging features of hibernomas on computed tomography (CT) and magnetic resonance (MRI)., Methods: Twelve hibernomas were retrospectively assessed with CT and MR imaging and compared to the histology of the specimen, Results: Nine females and three males with a mean age of 30 years were included. Ten tumors occurred in the thigh and two affected the subcutis of the periscapular and buttock regions. On eight CT scans, seven (87,5%) lesions were homogeneous and mildly to moderately hyperdense compared to subcutaneous fat while one lesion was heterogeneous with mixed hypo and hyperattenuating areas. On six T1W images, five (83,3%) lesions appeared homogeneous and hypointense relative to subcutaneous fat and one was heterogeneous. Incomplete fat suppression was depicted in all cases. All lesions displayed marked enhancement. Large intratumoral vessels were depicted in three of the 12 (25%) cases. Septations were depicted on four of the eight unenhanced CT and on all six MRI examinations., Conclusions: Hibernoma usually appears hypodense and hypointense relative to subcutaneous fat on pre-contrast CT and MR T1W with variable enhancement patterns and incomplete fat suppression on STIR or fat-saturated sequences. These characteristics relate directly to the presence of brown fat. However, atypical findings such as heterogeneous patterns of mixed fatty and non fatty components on unenhanced CT and MR T1W can be also encountered. Absence of large intratumoral vessels should not exclude hibernomas from the differential diagnosis of regional lipomatous tumors.

Background: Parosteal osteosarcoma is a well-differentiated variant of osteosarcoma that affects the surface of the bone. The imaging pattern is very typical. We report two cases mimicking an osteochondroma, radiologically and histologically and propose an explanation., Methods: The review of 86 parosteal osteosarcomas of bone revealed this atypical pattern only once. A consultation case was received in the same time, and added to ours. Patients were 28 years old and 56 years old females. Imaging studies included two radiographs, two CTscans, one MRI examination and one bone scan and the results were compared to histology., Results: On imaging, both lesions presented as ossified lobulated masses attached with a broad base to the underlying cortex. No radiolucent cleft separated the masses and the host bone and cortex continuity between the mass and the femur was seen, with medullary communication. The marrow of the mass had a different density and intensity compared to normal marrow. So, there were features of an osteochondroma (cortex and medullary continuity) and of a parosteal osteosarcoma (ossified marrow). Pathological assessment on the final specimen confirmed the presence of low-grade parosteal osteosarcomas, after an erroneous diagnosis of osteochondroma on the initial biopsy., Conclusions: Parosteal osteosarcoma can be rarely confused with osteochondroma. A radiologic-pathologic correlation is essential. Cortex continuity is the most misleading imaging feature that may occur in parosteal osteosarcomas. A knowledge of this misleading pattern will help diagnose the lesion from the beginning.