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12/2005: pages 163-178;
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ABSTRACT: Liposarcoma is the second most common malignancy of soft tissues. The commonly accepted classification of liposarcoma includes five basic histological categories: well-differentiated, myxoid, round cell, dedifferentiated and pleomorphic liposarcoma. The clinical behaviour of liposarcoma closely reflects its histological appearance, so that to identify the histological subtypes is very important for both prognosis and therapy. The aim of this study was to ascertain whether the histological features of liposarcoma subtypes can be correlated with MRI (Magnetic Resonance Imaging) and CT (Computed Tomography) findings by retrospectively evaluating nineteen cases of histologically-proved liposarcoma.
The MRI examinations performed over the past eight years on nineteen patients affected by liposarcoma were retrospectively reviewed. All patients underwent ultrasound and MRI examination; T2 and T1-weighted sequences were available in all cases and fat-saturated sequences in 4 cases; all patients were administered paramagnetic contrast material. CT scans were obtained in twelve patients. All patients had a biopsy, surgical resection and histology.
The study group had 7 well-differentiated, 8 myxoid, 3 pleomorphic and 1 round cell liposarcoma. Well-differentiated liposarcomas had largely lipomatous appearance on both CT and MRI, typically with septa and areas showing high signal intensity on T2w MR images and low signal intensity on T1w images, and slightly hypodense compared to the muscle in CT, representing the sarcomatous areas. Myxoid liposarcomas were mildly heterogeneous with typical high signal intensity on T2w images and isointense to the muscle in T1w images, with lacy or linear septa of fatty tissue in six cases. The pleomorphic and round-cell subtypes demonstrated marked heterogeneity on MR images, with areas of necrosis and heterogeneous contrast enhancement, indistinguishable from other high-grade sarcomas.
Well-differentiated liposarcoma may be distinguished from other types of liposarcoma by its largely lipomatous appearance. Myxoid liposarcoma may be distinguished on the basis of its homogeneous or mildly heterogeneous structure due to the large amounts of the extracellular myxoid material that give it its typical MR appearance. Both well-differentiated and myxoid liposarcomas, the most common types accounting for about 50% of all liposarcomas, have a more favourable clinical behaviour than the other histological types. Differentiation of these from the other histological types of liposarcoma therefore has a high significance for prognosis and therapeutical approach. On the basis of our experience and of the literature, we believe that diagnostic imaging and in particular the MR examination may lead to a correct diagnosis.
La radiologia medica 10/2002; 104(3):140-9. · 1.44 Impact Factor
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ABSTRACT: Neuroradiological findings in two cases of isolated cerebral amyloidoma are reported. Case 1: A 15-year-old male admitted because of left jacksonian seizure. Case 2: A 31-year-old man admitted because of temporal seizures. In both patients, CT scans showed spontaneously hyperdense and enhancing nodules. On MRI, lesions displayed signals isointense with surrounding edema on T1-weighted sequences and mildly hypointense on T2-weighted sequences if compared with edema; peripheral contrast enhancement after gadolinium administration was present. Histopathological examination of both specimens revealed the presence of acellular eosinophilic hyalinized material consistent with amyloid, forming confluent nodular masses in the white and gray matter.
Neuroradiology 05/2002; 44(4):333-7. · 2.82 Impact Factor
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ABSTRACT: This study aims to evaluate the usefulness of paramagnetic contrast medium (Gadolinium) in the staging and re-staging of soft tissue tumors using Magnetic Resonance Imaging (MRI).
Sixty patients affected by soft tissue sarcoma of different histotype were retrospectively evaluated. Age ranged from 23 to 78 years. Data were obtained from the musculoskeletal tumor database of our Department of Radiology and cases from the last 7 years (1993-1999) entered this study. All the patients were submitted to ultrasound (US) and to routine and enhanced MR examinations (SE T1-weighted and Fast-SE T1 and T2-weighted before and after fat saturation pulse; GE T2-weighted sequences). At least two different scan planes were obtained depending on the major axis of the lesion. Once imaging information had been obtained all the patients underwent surgery and histology. After surgery, the mean follow-up period was 18 months. Paramagnetic contrast medium (0,2mmol/Kg) was administered in all the MR follow-up examinations.
Lesions included adipose histology in 15 cases; muscular histology in 12 cases; fibro-hystiocitic histology in 20 cases; synovial histology in 8 cases; mixed histology in 5 cases. Excluding lesions with mainly adipose content showing obvious high signal intensity on T1-weighted sequences, the other lesions rarely presented MR features specific to histological category also after contrast medium administration. In all the cases MRI allowed an accurate definition of the lesion boundaries to exclude or demonstrate neighbor region invasion. In 11 cases, MRI was able to demonstrate the presence of a recurrent tumor. In 2 out of 11 cases, recurrences were detected out only after intravenous administration of Gadolinium, plain MRI having failed to recognize them.
Despite the absence of specific MRI signs of the different soft tissue tumor histotypes also after Gadolinium administration, MRI remains the best imaging technique to establish the exact morphology of the lesions and to establish the invasion of the neighbor regions by the tumors. The presence of regional spreading of the tumor has to be considered a sign of malignancy. During the follow-up, the use of Gadolinium allows the MR examinations to reach high sensitivity levels and makes it also possible to recognize local recurrences of a very small size. Considering our experience we recommend, whenever a follow-up of resected soft tissue tumors is requested, to perform MRI examination before and after intravenous Gadolinium administration.
La radiologia medica 07/2001; 101(6):444-55. · 1.44 Impact Factor
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ABSTRACT: During the last decades there have been various attempts to define the characteristics of white matter inflammatory diseases. Most of the authors concerned agree in considering Schilder's myelinoclastic diffuse sclerosis (SD), Devic's neuromyelitis optica (NMO) and Balo's concentric sclerosis to be variants of typical multiple sclerosis (MS). Moreover, in childhood even typical MS presents more aggressive behaviour, with frequent evidence of giant, tumefactive, necrotic or haemorrhagic plaques.
The authors review the literature and cite atypical cases that appear to be intermediate between MS and SD, NMO and SD.
Finally, some critical revisions are proposed concerning cases with clinical presentation, history, laboratory and MR findings intermediate between those of acute disseminated encephalomyelitis and of MS.
Child s Nervous System 05/2001; 17(4-5):202-10. · 1.54 Impact Factor
