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At least 91 records · Page 5Linked to original sources
PubMed2002

Frequency of sentinel lymph node metastases in patients with favorable breast cancer histologic subtypes.

BACKGROUND: The need for axillary nodal staging in favorable histologic subtypes of breast cancer is controversial. METHODS: Patients with clinical stage T1-2, N0 breast cancer were enrolled in a prospective, multi-institutional study. All patients underwent sentinel lymph node (SLN) biopsy followed by completion level I/II axillary dissection. RESULTS: SLN were identified in 3,106 of 3,324 patients (93%). Axillary metastases were found in 35% and 40% of patients with infiltrating ductal carcinoma and infiltrating lobular carcinoma, respectively. Among tumor subtypes, positive nodes were found in 17% of patients with pure tubular carcinoma, 7% of patients with papillary cancer, 6% of patients with colloid (mucinous) carcinoma, 21% of patients with medullary carcinoma, and 8% of patients with DCIS with microinvasion. CONCLUSIONS: Patients with favorable breast cancer subtypes have a significant rate of axillary nodal metastasis. Axillary nodal staging remains important in such patients; SLN biopsy is an ideal method to obtain this staging information.

Adenocarcinoma↗
PubMed2003

Expression of MMP-2 and -9 in short-term cultures of meningioma: influence of histological subtype.

Matrix metalloproteinases (MMPs) belong to a super family of endopeptidases which have been implicated as crucial mediators of angiogenesis and tumour invasion in brain tumours. This study was undertaken in an attempt to establish the relationship between 2 specific MMPs and the main classical subtypes of meningioma. We examined the expression of MMP-2 and -9 (gelatinase-A and -B respectively), by gelatin zymography, in a series of 18 cell cultures derived from human meningiomas of a range of histological subtypes and grades of malignancy, including 7 meningothelial, 6 transitional, 2 fibroblastic and 3 atypical meningiomas. Our findings indicate that generally, the meningothelial subtype, had the weakest expression, the transitional subtype had an intermediate expression whereas the fibroblastic subtype had the strongest expression of both MMP-2 and -9. There was no correlation between other clinicopathological features (age, sex, site of tumour) and the level of MMP-2 and -9 expression. Although, the number of samples in this study is limited, these findings suggest that there may be a trend for association between the expression of these 2 MMPs and the main classical histological subtypes of meningioma.

Adult↗
PubMed1997

Genetic alterations in gastric cancer: relation to histological subtypes, tumor stage, and Helicobacter pylori infection.

BACKGROUND & AIMS: A different spectrum of genetic changes including p53, c-erbB-2, c-met, adenomatous polyposis coli (APC), and deleted in colorectal cancer (DCC) is involved in gastric cancer (GC). The aim of this study was to correlate these alterations with histological subtypes, tumor stages, and Helicobacter pylori infection. METHODS: Specimens of 163 patients with GC were immunostained for p53, c-erbB-2, and c-met, and polymerase chain reaction was performed in them to determine loss of heterozygosity (LOH) of APC and DCC. RESULTS: Overexpression of p53 was more frequent in early intestinal than early diffuse GC and was noted in the stage progression of diffuse but not intestinal GC. Overexpression of c-erbB-2 occurred more commonly in intestinal GC and advanced GC of both types. Overexpression of c-met was greater in diffuse GC, particularly at advanced stage. LOH of APC was more common in intestinal GC irrespective of the stage but rarely in diffuse GC. LOH of DCC occurred primarily in advanced intestinal GC and infrequently in early GC or advanced diffuse GC. Alterations of these five genes were not correlated with H. pylori infection. CONCLUSIONS: A distinct genetic pathway exists in gastric carcinogenesis of different histological subtypes and their tumor progression, in which H. pylori infection may play an equal role or no role.

Adenomatous Polyposis Coli↗
PubMed2006

Histologic subtype of metastatic renal cell carcinoma predicts response to combined immunochemotherapy with interleukin 2, interferon alpha and 5-fluorouracil.

OBJECTIVES: Combined immunochemotherapy with interleukin 2 (IL-2), interferon alpha (IFN-alpha), and 5-fluorouracil (5-FU) is an established first-line therapy for metastatic renal cell carcinoma (RCC). However, data on histologic parameters predictive of clinical benefit are rare. In this study, we evaluated the response to immunochemotherapy in the main histologic subtypes of renal cell carcinoma and performed a subgroup analysis of inoperable patients. METHODS: From 164 patients treated with one or two cycles of combined immunochemotherapy, radical nephrectomy had revealed 22 cases of papillary RCC (pRCC; 13.4%) and 131 cases of clear cell RCC (ccRCC; 79.9%). In the remaining 11 (6.7%) their disease was inoperable. The overall response rates were evaluated according to World Health Organization criteria. RESULTS: For ccRCC and inoperable disease, responses of 34.4% and 27.3% after one cycle and 28.8% and 16.7% after two cycles, respectively, were noted. In contrast, no patient with pRCC showed any response after two cycles of combined immunochemotherapy. CONCLUSIONS: No objective response was seen in patients with pRCC. Hence, the use of immunotherapeutic agents must be questioned in this histologic subtype.

Adult↗
PubMed2001

Polymorphisms at the glutathione S-transferase GSTM1, GSTT1 and GSTP1 loci: risk of ovarian cancer by histological subtype.

The phase II glutathione S-transferases (GSTs) GSTT1, GSTM1 and GSTP1 catalyse glutathione-mediated reduction of exogenous and endogenous electrophiles. These GSTs have broad and overlapping substrate specificities and it has been hypothesized that allelic variants associated with less effective detoxification of potential carcinogens may confer an increased susceptibility to cancer. To assess the role of GST gene variants in ovarian cancer development, we screened 285 epithelial ovarian cancer cases and 299 unaffected controls for the GSTT1 deletion (null) variant, the GSTM1 deletion (null) variant and the GSTP1 codon 104 A-->G Ile-->Val amino acid substitution variant. The frequencies of the GSTT1, GSTM1 and GSTP1 polymorphic variants did not vary with tumour behaviour (low malignant potential or invasive) or p53 immunohistochemical status. There was a suggestion that ovarian cancers of the endometrioid or clear cell histological subtype had a higher frequency of the GSTT1 and GSTM1 deletion genotype than other histological subgroups. The GSTT1, GSTM1 and GSTP1 genotype distributions did not differ significantly between unaffected controls and ovarian cancer cases (overall or invasive cancers only). However, the GSTM1 null genotype was associated with increased risk of endometrioid/clear cell invasive cancer [age-adjusted OR (95% CI) = 2.04 (1.01-4.09), P = 0.05], suggesting that deletion of GSTM1 may increase the risk of ovarian cancer of these histological subtypes specifically. This marginally significant finding will require verification by independent studies.

Adenocarcinoma, Clear Cell↗
PubMedDate not supplied

Common and uncommon histologic subtypes of renal cell carcinoma: imaging spectrum with pathologic correlation.

Renal cell carcinoma (RCC) is a cause of significant morbidity and mortality, with an estimated 35,000 new cases and 12,480 deaths in the United States in 2003. Recent advances in imaging technology, pathology, urology, and oncology permit early diagnosis of RCC and facilitate optimal management. The 2004 World Health Organization classification for renal neoplasms recognizes several distinct histologic subtypes of RCC. These subtypes include clear cell RCC, papillary RCC, chromophobe RCC, hereditary cancer syndromes, multilocular cystic RCC, collecting duct carcinoma, medullary carcinoma, mucinous tubular and spindle cell carcinoma, neuroblastoma-associated RCC, Xp11.2 translocation-TFE3 carcinoma, and unclassified lesions. Different histologic subtypes of RCC have characteristic histomorphologic and biologic profiles. Clear cell RCC is the most common subtype and has a less favorable prognosis (stage for stage) than do papillary RCC and chromophobe RCC. Collecting duct carcinoma and renal medullary carcinoma are associated with aggressive clinical behavior and a poor prognosis.

Carcinoma, Renal Cell↗
PubMedDate not supplied

Protein expression profiles of non-small cell lung carcinomas: correlation with histological subtype.

Of the four major subtypes of lung cancer, three subtypes, namely squamous cell lung carcinomas, adenocarcinomas and large cell carcinomas are usually combined within the larger group of non-small cell lung carcinomas (NSCLC). However, the heterogeneity that exists within any given tumor has also been clearly demonstrated. In order to study whether or not the protein expression profile is different in the histological subtypes of NSCLC, the expression of several parameters including proto-oncogene and suppressor gene products, proliferative, apoptotic, angiogenic and resistance factors was evaluated immunohistochemically in 139 NSCLC (45 adenocarcinomas and 94 squamous cell lung carcinomas). In both histological subtypes the percentage of positively-stained parameters was determined. The expression of the proteins ERBB2, JUN, RAS and tissue factor was significantly higher in adenocarcinomas compared to squamous cell lung carcinomas. In contrast, all resistance proteins analyzed were more frequently expressed in squamous cell lung carcinomas in comparison to adenocarcinomas, though only GST-pi reached statistical significance. Apoptotic factors and angiogenic factors were higher in adenocarcinomas, but these differences did not reach statistical significance. In conclusion, the protein expression profiles of adenocarcinomas and squamous cell carcinomas differ from each other. Squamous cell lung carcinomas in comparison to adenocarcinomas are characterized by a down-regulation of some oncogenes and an up-regulation of several resistance factors. These findings could explain the different biological behaviour and treatment response of these tumours.

Adenocarcinoma↗
PubMed2002

Ki-67 expression level, histological subtype, and the International Prognostic Index as outcome predictors in mantle cell lymphoma.

OBJECTIVES: Mantle cell lymphoma (MCL) is characterised by translocation t(11;14) (q13;q32) leading to rearrangement of bcl1/CCND1 and overexpression of the cell-cycle regulatory protein cyclin D1. We assessed the significance of the cell proliferation rate as an outcome predictor with the five components of the International Prognostic Index (IPI) and the histological subtypes of MCL. PATIENTS AND METHODS: The hospital case records and histopathological material of 127 patients diagnosed with MCL in a single centre were reviewed. The cell proliferation rate was assessed by Ki-67 immunostaining and mitosis counting. Cox's multivariate regression model was used in multivariate survival analyses. The median follow-up time was 87 months. RESULTS: The mantle zone/nodular subtype of the common variant (19%) was associated with median survival of 70 months, the diffuse subtype of the common variant (64%) of 35 months, and the blastoid subtype (17%) of 11 months (P < 0.001). Patients with Ki-67 expression in > or = 26% (the upper tertile) of the lymphoma cells had median survival of only 13 months as compared with 45 months in the rest of the patients (P < 0.001). In a multivariate analysis high Ki-67 expression, Ann Arbor stage III-IV, and age over 60 yr had independent influence on survival, whereas serum lactate dehydrogenase level, the number of extranodal disease sites, and performance status did not. CONCLUSIONS: The IPI may not be an optimal tool for outcome prediction in MCL, and a better prognostic index may be obtained by including Ki-67 expression and possibly the histological subtype in the index.

Aged↗
PubMed1996

Allele loss from large regions of chromosome 17 is common only in certain histological subtypes of ovarian carcinomas.

Using a panel of ten polymorphic markers, we examined the frequency of loss of heterozygosity (LOH) on chromosome 17 in 55 sporadic ovarian tumours. LOH on 17p and 17q was observed to be 50% and 62% respectively. LOH at D17S5 was detected in 24/36 (67%) of malignant cases and in 19/43 (44%) at TP53; the marker D17S855 intragenic to the BRCA1 gene showed allele loss in 50% (20/40) cases. The data presented here suggest that loss of the whole chromosome 17 is a relatively frequent event (30%) in ovarian carcinomas and this observation is especially frequent for serous, transitional cell and anaplastic histological subtypes. Mucinous and endometrioid ovarian tumours showed only short interstitial deletions (4/11, 36%). The overall frequency of the short deletions was relatively low (7/43, 16%) in our panel of carcinomas. Amplification of c-erbB-2/neu oncogene was detected in 32% (11/34) of the carcinomas tested; the gene was amplified only in those histological subtypes in which high incidence of LOH on chromosome 17 was observed, and was associated with advanced stages of the disease. We conclude that different histological types of tumour may have different aetiological mechanisms, and tumour-suppressor genes on chromosome 17 might be associated specifically with serous and transitional cell ovarian carcinomas.

Alleles↗
PubMed2002

Height, weight, menstrual and reproductive factors and risk of gastric cancer among Japanese postmenopausal women: analysis by subsite and histologic subtype.

To clarify whether reproductive factors have an impact on gastric cancer in Japanese females, a case-control study was conducted using data from the Hospital-based Epidemiologic Research Program at Aichi Cancer Center (HERPACC), Japan. The study subjects included 365 postmenopausal women with gastric cancer and 1,825 age-class frequency-matched noncancer outpatients presenting at Aichi Cancer Center in 1988-1998. Cases were further divided with regard to the anatomic subsite (upper third, middle third, lower third) and histologic subtypes (differentiated, nondifferentiated) and the association was evaluated using odds ratios (ORs) estimated by the logistic regression model, adjusting for potential confounding factors. A high body weight and corresponding body mass index at age 20 moderately increased the risk of gastric cancer, especially for middle third and nondifferentiated cancers. Risk fluctuation with early or late age at menarche and menopause and total duration of fertility was not consistent. Individuals with a high age at first parity tended to show decreased risk of cancer, irrespective of their subsite or histologic subtype. The ORs were decreased with a short average period of breastfeeding, especially for upper third and nondifferentiated cancers. From these results, however, it appears that height, weight, menstrual and reproductive factors have less impact on gastric cancer than environmental factors such as smoking and dietary habits or family history of gastric cancer.

Adult↗
PubMed1998

Detection of single and associated lesions of the Bcl-1, Bcl-2, Bcl-6, c-myc, p53 and p16 genes in B-cell non-Hodgkin's lymphomas: value of molecular analysis for a better assignment of the histologic subtype.

BACKGROUND AND OBJECTIVE: Molecular genetic abnormalities have been frequently described in non-Hodgkin's lymphomas (NHL). These lesions have been associated with specific entities, allowing a better categorization of NHL. However, these abnormalities are not as specific as initially described and their association is still unknown. DESIGN AND METHODS: By Southern blot and polymerase chain reaction, we have simultaneously analyzed the proto-oncogenes Bcl-1, Bcl-2, Bcl-6, c-myc and MLL and the tumor suppressor genes p53 and p16, in 100 unselected B-cell NHL patients at diagnosis, to establish its incidence throughout the different NHL subtypes, defined both by Working Formulation and REAL classifications, and to assess the frequency of co-existence of two or more genetic lesions within each individual patient. RESULTS: Fifty two cases displayed some genetic abnormality. Bcl-1, altered in 12 cases, was highly specific to mantle cell lymphomas (57% of them), but 6 cases had a different histologic subtype. Bcl-2 was rearranged in 26 cases: 70% in follicular lymphomas (FL) and 20% in diffuse large cell lymphomas; these abnormalities were also present in other subtypes, i.e. marginal lymphomas (30%). Bcl-6 abnormalities were mostly found in diffuse large cell lymphomas (29%) but also found in other subgroups, like FL (14%). C-myc rearrangements were specific to Burkitt's lymphoma. MLL gene was always germline. Deletions and/or rearrangements of p53 and p16 genes were rare (4% and 8% of all cases, respectively). Finally, association of genetic lesions was a relatively common finding (13% of cases), especially in cases with adverse prognostic morphologies according to the REAL. INTERPRETATION AND CONCLUSIONS: Molecular abnormalities are frequent in NHL at diagnosis, not only as unique lesions but also associated. A relative high specificity of some alterations was seen, thereby contributing to a better assessment of the histological subtype.

Blotting, Southern↗
PubMed2004

Lumpectomy margins are affected by tumor size and histologic subtype but not by biopsy technique.

OBJECTIVE: The effect of the type of biopsy (needle vs. excisional) on lumpectomy margin status has not been well established. The objective of this study was to determine whether needle biopsy is associated with a higher positive margin rate at time of lumpectomy. METHODS: We evaluated this hypothesis in the setting of a prospective multi-institutional study. A total of 3975 patients were enrolled in the University of Louisville Breast Cancer Sentinel Lymph Node Study from May 7, 1998 to June 3, 2003. Patients who underwent lumpectomy at the time of their sentinel lymph node biopsy were the focus of this analysis. Patients with clinical stage T1 N0 and T2 N0breast cancer were eligible; 29 patients were found to have T3 tumors on final pathology. Pathologists at each institution defined margin positivity, and tumor at the inked margin of resection was the study guideline. RESULTS: Median patient age was 59 years, and median tumor size was 1.5 cm. A total of 2658 patients underwent lumpectomy with the following results. The cancer of 1515 patients was diagnosed by fine-needle or core-needle biopsy and of 821 patients was diagnosed by excisional biopsy; in 322 patients the method of diagnosis was unknown. The type of previous biopsy did not significantly affect the positive-margin rate at the time of lumpectomy (13.3% vs. 11.0% for needle and excisional biopsy, respectively, P = 0.107). However, patients with larger tumors were more often found to have a positive margin (11.4% vs. 13.9% vs. 27.6% for T1, T2, and T3 tumors, respectively; P = 0.010). No difference was found in margin status after excision of palpable versus nonpalpable tumors (10.6% vs. 10.9%, respectively, P = 0.743). Histologic subtype, however, did affect margin status (15.8% vs. 9.8% positive margins for lobular vs. ductal type, respectively, P = 0.003). CONCLUSIONS: In this multi-institutional study, increasing tumor size and lobular histologic subtype were associated with a greater likelihood of a positive margin. The type of biopsy, needle or excisional, had no effect on the ability to achieve negative margins.

Adult↗
PubMed2001

Differential association of the codon 72 p53 and GSTM1 polymorphisms on histological subtype of non-small cell lung carcinoma.

Traditionally, non-small cell lung cancer (NSCLC) has been evaluated as a unique entity in genotyping studies. However, recent biological data suggest that different NSCLC subtypes, specifically adenocarcinomas (AC) and squamous cell carcinomas (SCC), differentially alter cancer behavior. Several studies have associated a p53 polymorphism at codon 72 with NSCLC susceptibility. This study investigated whether different p53 genotypes altered the overall risk of developing AC versus SCC. Polymorphisms in metabolizing enzymes, together with prolonged exposure to tobacco carcinogens, can result in accumulation of DNA damage; these effects may potentiate the effects of subtle differences in p53 function. Thus, interactions between polymorphisms of p53 and either GSTM1 or GSTT1 were also evaluated. We analyzed 1168 incident lung cancer cases and 1256 control subjects using multiple logistic regression. Histological data were available for 1144 cases (98%): 585 with AC, 284 with SCC, and 275 with other histological subtypes (large cell, small cell, mixed, and other). An increase in the NSCLC risk posed by the p53 Pro allele (versus Arg/Arg) was seen in AC compared with controls [adjusted odds ratio (OR), 1.36; 95% confidence interval (CI), 1.1-1.7] but not in SCC (adjusted OR, 1.04; 95% CI, 0.8-1.4). Among AC and SCC cancer patients, individuals with the GSTM1-null genotype had an OR of 1.80 (95% CI, 1.1-2.8; case-only analysis) of having AC versus SCC if they also carried a p53 Pro allele. We conclude that different genotype combinations of p53 and GSTM1 increase the risk of developing specific histological subtypes of NSCLC.

Adenocarcinoma↗
PubMed1983

Histological subtypes or grading of pulmonary adenocarcinoma. A histochemical and electron microscopic study.

To reveal whether the different histological subtypes of pulmonary adenocarcinoma are composed of different types of cells, we analyzed basic mucus histochemistry and ultrastructural features in a series of 61 adenocarcinomas correlating the findings with four ways of histological classification and grading. 82% of the tumours were composed of a single and 18% of two or more cell types. The original WHO classification had no association with the histochemical or ultrastructural features studied. A modified WHO classification, however, based on the prevailing subtype, had significant associations with five, a classification based on prevailing growth pattern with four, and histological grading with eight histochemical and electron microscopic features. The results suggest that it is more important to classify pulmonary adenocarcinomas by histological grades than by subtypes.

Adenocarcinoma↗
PubMed1979

Small cell carcinoma of the lung. Prognosis in relation to histologic subtype.

Forty-six of 59 patients with small cell carcinoma of the lung who were treated with multiple drug chemotherapy and radiotherapy were subclassified according to the World Health Organization classification. Subtyping was not possible in the 13 other patients who were diagnosed on sputum cytology findings alone. There was no significant difference in extent of disease, response, duration of response to treatment, or median survival between the different subtypes. Two main difficulties arise in applying the subtyping classification. First, many tumors showed features of several histologic subtypes, implying the existence of a morphologic continuum within the general group of small cell anaplastic carcinomas. Second, tissue crushing artefact was common. Our results do not reveal any advantage in knowing the tumor subtype. It remains essential to differentiate small cell anaplastic carcinoma from other forms of lung carcinoma not responsive to chemotherapy.

Antineoplastic Agents↗
PubMed1992

Distribution of histologic subtypes and sex ratio in various primary sites of lymphocytic lymphoma.

To examine the distribution of histologic subtypes and sex ratio in each primary site of lymphoma, 1,169 histologically proven cases of lymphocytic lymphoma were analyzed. The location of tumor was nodal in 615(53%) and extranodal in 517(44%), patients with the gastrointestinal tract being the most common. The incidence was predominantly in males for all histologic types and in nodal and extranodal sites, except for a predominance of females in extranodal lymphoplasmacytic(Lp-cytic), lymphoplasmacytoid(Lp-cytoid) tumors. Frequency of the Lp-cytic/Lp-cytoid type among all types of lymphoma in females was about 2.7 times more frequent in extranodal than in nodal sites. The most striking example was thyroid lymphoma in which the frequency of Lp-cytic/Lp-cytoid type was 36% in female and 0% in male patients. Including this type of lymphoma, frequency of low grade lymphoma in females was higher in extranodal sites than in nodal sites.

Adolescent↗
PubMed1996

MDM2 and p53 protein expression in the histologic subtypes of endometrial carcinoma.

The frequency of p53 protein overexpression differs among the histologic subtypes of endometrial carcinoma, from 21 to 48% in endometrioid carcinoma but from 80 to 86% in papillary serous carcinoma. Although p53 gene mutation can closely correlate with p53 protein overexpression in papillary serous carcinomas, high expression of p53 protein may also occur without detectable gene mutation in endometrioid carcinomas. Because MDM2 protein can bind mutant and wild-type p53 protein, we examined MDM2 and p53 protein expression in 27 endometrioid carcinomas and compared their expression patterns with those of 25 uterine papillary serous carcinomas. We detected p53 protein in 14 (52%) of the 27 endometrioid carcinomas but in 21 (84%) of the 25 papillary serous tumors (P = 0.02). MDM2 expression was more commonly detected in the endometrioid carcinomas. Nineteen (70%) of the 27 cases showed expression compared with 9 (36%) of the 25 papillary serous carcinomas (P = 0.03). p53 Expression correlated closely with MDM2 expression in endometrioid carcinomas but not in the papillary serous carcinomas. In endometrioid carcinomas, MDM2 was detected in 13 (93%) of 14 p53-positive carcinomas but in only 6 (46%) of 13 p53-negative tumors (P = 0.01). In papillary serous carcinomas, MDM2 was detected in 9 (43%) of 21 p53-positive carcinomas but in none of the 4 p53-negative tumors (P value not significant). These findings suggest that although high rates of p53 protein overexpression are most frequently associated with p53 gene mutation in uterine papillary serous carcinoma, p53 protein overexpression in endometrioid carcinoma is frequently associated with MDM2 overexpression. The selective correlation of MDM2 expression with p53 expression in endometrioid carcinomas but not in papillary serous carcinomas suggests an active role for MDM2 in binding and inactivating p53 in endometrioid carcinomas, leading to its overaccumulation and potentially impeding repair to damaged DNA. Additional study as to the cause of increased MDM2 expression in endometrial carcinoma, e.g., gene amplification, enhanced translation, or rearrangement, is indicated.

Adenocarcinoma↗
PubMed2002

Soft tissue liposarcoma: histological subtypes, MRI and CT findings.

PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. DISCUSSION AND CONCLUSIONS: 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.

Adult↗