MDM2 Staining Research Articles

The Characteristics of magnetic resonance imaging and immunohistochemical findings in de-differentiated liposarcoma.

Radiological imaging in Dedifferentiated liposarcoma (DDLPS) often shows the coexistence of fatty and non-fatty solid components; however, it has been shown that when fatty components were not identified on magnetic resonance imaging (MRI), the diagnosis of DDLPS would not have been diagnosed if immunohistochemical (IHC) staining had not been performed. The aim of this study was to investigate the pattern of MRI and relationship between MRI and IHC findings in DDLPS. We retrospectively reviewed the cases of 25 patients with DDLPS. To identify the MRI spectrum of DDLPS, tumors were classified into the following four categories based on MRI findings: I = a well-defined fatty mass and juxtaposed well-defined non-fatty mass, II = a non-fatty component within a predominantly fatty mass, III = a focal fatty component within a large non-fatty mass, and IV = a non-fatty mass with atypical MRI findings. IHC staining for CDK4, MDM2, and p16 were evaluated. Category IV tumor was the most common tumor in this population. Of the 22 patients who underwent IHC staining, MDM2, CDK4, and p16 were positive in 21, 20, and 19 patients, respectively. MDM2 was positive in all 11 patients with category IV tumors; CDK4 and p 16 were positive in 10 and eight patients, respectively. There was no difference of survival between the patients with category I, II and III and category IV. DDLPS without fatty components on MRI scans was mostly found. We recommend IHC staining to screen for DDLPS even if the tumors in STS cases have a non-fatty component.

Multivariate evaluation of prognostic markers in synovial sarcoma

AimsSynovial sarcoma (SS) is an aggressive neoplasm but with varied clinical outcomes despite standard treatment protocols. Several clinicopathological features and immunohistochemical stains have been proposed as prognostic markers in SS....

Atypical Pleomorphic Lipomatous Tumor: Expanding Our Current Understanding in a Clinicopathologic Analysis of 64 Cases.

Atypical pleomorphic lipomatous tumor (APLT) is a recently recognized adipocytic neoplasm that lies on a spectrum with atypical spindle cell lipomatous tumor (ASCLT). APLT/ASCLT are included together in the fifth edition World Health Organization Classification of Soft Tissue and Bone Tumours; however limited data on APLT have emerged since its first description in 2017. This study aims to further define the clinicopathologic features of APLT in a large series of 64 cases. Histologic features and ancillary studies were reviewed, and clinical and follow-up data were obtained from referring institutions. Immunohistochemistry for MDM2, CDK4, CD34, Rb, S100, and desmin was performed in cases with available material. Patients were 24 females and 40 males, and the median age was 61 years (range, 20 to 89 y). Tumors arose in upper limb (33%), lower limb (31%), trunk (23%), head and neck (8%), breast (3%), and inguinal region (2%), with a median size of 5.4 cm (range, 1.5 to 14.5 cm). Tumor depth was mostly subcutaneous or deep/subfascial. Microscopically, APLTs were variably composed of atypical spindle and pleomorphic cells, adipocytes, and lipoblasts, often showing infiltrative growth, myxoid or collagenous stroma, and multinucleate floret cells. Mitoses were infrequent and necrosis was consistently absent. By immunohistochemistry, tumors expressed CD34 (63%), S100 (19%), and desmin (28%). APLT showed frequent loss of Rb (79%; 46/58). Rare cases showed staining for MDM2 (2%) or CDK4 (12%); however, fluorescence in situ hybridization was negative for MDM2 amplification in all cases tested (0/22). Follow-up in 28 patients (median duration: 21 mo) revealed a single patient with local recurrence (4%); no patient developed metastatic disease. Despite its frequently infiltrative growth, nuclear pleomorphism, and hypercellularity which can mimic sarcoma, APLT behaves in an indolent manner and should be distinguished from its more aggressive mimics, including atypical lipomatous tumor/well-differentiated liposarcoma and pleomorphic liposarcoma. Immunohistochemistry for CD34, S100, desmin, and Rb (demonstrating loss), as well as exclusion of MDM2 amplification, can support the diagnosis.

Atypical and incomplete pulmonary hypertrophic osteoarthropathy in the left distal femur: a case report

BackgroundPulmonary hypertrophic osteoarthropathy (PHO) is a rare paraneoplastic syndrome that mainly occurs in patients with lung cancer. Most symptoms occur symmetrically, and unilateral symptoms without clubbing are infrequent. This report presents the case of a rare atypical symptom that was highly suspected of being PHO.Case presentationA 77-year-old woman with swelling and severe pain in the left femur for 2 months was referred to our hospital. Radiography revealed a remarkably osteogenic thickening and sclerotic lesion in her distal femur. Preliminary diagnoses of malignant bone tumor and hematological tumor were made based on laboratory test results, radiological examination, and clinical manifestation. A needle biopsy was performed, which ruled out the diagnosis of malignant bone tumors. A low-grade bone tumor was still suspected. After that, en bloc resection was performed, followed by replacement of the femur with a mega-prosthesis. Pathological analysis revealed no malignant tumor cells, and immunohistochemical staining for CDK4 and MDM2 yielded negative results. Meanwhile, pulmonary large cell carcinoma was identified on biopsy. Based on published studies, a diagnosis of atypical PHO was made according to clinical and imaging manifestations.ConclusionsThis is an infrequent case of PHO with unilateral symptoms in the left femur. When clinical manifestations and radiological findings are inconsistent with the pathological results, the possibility of benign lesions with malignant clinical manifestations or imaging features should be carefully considered.

Parathyroid adenoma with prominent lymphocytic infiltration: A potential pitfall in frozen sections and cytology reporting

Introduction: Parathyroid adenoma with prominent lymphocytic infiltration is rare, with only 12 cases reported in the English scientific literature. All these cases were not related to synchronous autoimmune or IgG4-related disease and presented clinically with primary hyperparathyroidism. Case presentation: A 65-year-old woman presented with hypercalcemia and a neck mass, suggestive of parathyroid adenoma. She underwent parathyroidectomy and histopathological examination of the specimen showed a hypercellular parathyroid nodule comprising mature lymphoid cells admixed with parathyroidal chief cells. A comprehensive immunohistochemistry panel confirmed the benign nature of the lesion. The patient remains asymptomatic a year after the surgery. Discussion: Parathyroid adenoma with prominent lymphocytic may be misdiagnosed as a lymph node at frozen section or cytology smears by an unsuspecting pathologist or cytologist, if the lymphoid component is predominant on the slide examined. Additionally, the morphology could be misinterpreted as a metastasis of parathyroid carcinoma into a peri-thyroidal lymph node. For this distinction, correlation with clinical and radiological findings is crucial and clues to adenoma include presence of a rim of uninvolved parathyroid parenchyma, low mitotic activity (<5%) and positive staining for parafibromin, bcl-2 and MDM2 on immunohistochemistry.

Lack of MDM2 interpretation guidelines contribute to diagnostic difficulty in a case of undifferentiated sarcoma

Undifferentiated sarcomas are malignant mesenchymal neoplasms lacking any specific line of differentiation and are typically a diagnosis of exclusion requiring supplemental diagnostic testing. We present a case of a 68 year old male with a thigh mass. Microscopic evaluation revealed a spindle and epithelioid cell neoplasm with pleomorphic nuclei arranged in vague, irregular fascicles and positive nuclear MDM2 staining. Fluorescence in situ hybridization (FISH) analysis demonstrated 36.2 average MDM2 signals and 31.7 average centromere 12 signals per cell (1.1 ratio). Although a dedifferentiated liposarcoma is defined by MDM2 amplification, the lack of an adjacent well differentiated liposarcoma component and radiographic characteristics argued against a lipomatous tumor in this case, leading to a diagnosis of undifferentiated sarcoma, despite the markedly increased MDM2 copy number. With expanding utilization of molecular and cytogenetic testing of tumors, this case highlights questions regarding the interpretation and incorporation of these results in diagnostic soft tissue pathology.

MDM2 and CDK4 Immunohistochemistry: Should It Be Used in Problematic Differentiated Lipomatous Tumors?: A New Perspective.

Although most cases of atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) can be diagnosed solely on the basis of histologic features, those lacking diagnostic histologic features require ancillary studies for accurate classification. Fluorescent in situ hybridization (FISH) for amplification of MDM2 has been considered the gold standard for diagnosis in these situations. Immunostaining for MDM2 and/or CDK4 has been adopted as a surrogate method because of its high concordance rate with FISH and lower cost. However, studies examining the concordance of the 2 methods have been based preferentially on cases in which the diagnosis could be established histologically. No study has explored the concordance between the 2 methods in histologically ambiguous cases or in cases in which the diagnosis of ALT/WDL is not apparent after a review of all slides. To address this, we performed immunostaining for MDM2 and CDK4 on 183 well-differentiated lipomatous tumors that could not be diagnosed on purely histologic grounds and that were, therefore, subjected to FISH analysis. These included ALT/WDLs (n=56), lipomas (n=96), and lipoma variants (n=31). Staining for MDM2 and CDK4 was noted in 25/56 and 23/56 ALT/WDL, respectively, giving a sensitivity of 45% and 41% and a specificity of 98% and 92%. Staining was noted exclusively in the nuclei of atypical cells and not in the nuclei of adipocytes. Staining for MDM2 and CDK4 occurred in 2/125 and 10/117 benign lipomatous lesions, respectively. False-positive staining was equivalent in intensity to ALT/WDL. We conclude that MDM2 and CDK4 staining is a relatively insensitive method for diagnosing ALT/WDL in cases that are histologically ambiguous, as staining is restricted to neoplastic cells with atypia that are underrepresented in these cases. Therefore, in cases like ours that closely simulate clinical practice, FISH is the more reliable and cost-effective option.

Abstract 4246: Comparison of pathology versus IHC-based ovarian carcinoma histology assignment using gene expression, DNA methylation, and clinical outcome data

Abstract Background: Epithelial ovarian cancer (EOC) is composed of five major histologic types: 1) high-grade serous carcinoma (HGSC), accounting for most cases (∼70%); and the rarer 2) clear cell, 3) endometrioid, 4) mucinous, and 5) low- grade serous carcinoma (LGSC). As EOC risk factors are histology specific, as are the site of precursor lesions, accurate subtyping is critical to understanding EOC prognostic factors and etiology. Our aim was to compare two currently employed histology assignment strategies using gene expression, DNA methylation, and clinical outcome data Methods: Histology assignment based on: a) pathologist, and b) an integrated pathologist and IHC prediction algorithm (pathIHC) (using ARID1A, CDKN2A, DKK1, HNF1B, MDM2, PGR, TP53, TFF3, VIM, and WT1 staining patterns), was compared for tumors of all histologies at the Mayo Clinic, Rochester. The 500 most variable probes from Illumina Methylation450 BeadChips (N = 259) and Agilent 4×44K expression arrays (N = 245) were used to perform unsupervised hierarchical clustering. Fisher's Exact test was used to test the association of clusters with histology. Cox proportional hazards regression analysis was used to test the association of clusters and histology with time to progression (TTP) and time to death (TTD). Results: Eighty-two percent of tumors were concordant between histology assignment strategies. Clustering based on methylation data produced two distinct clusters. PathIHC produced more homogenous clusters (p-value = 2.8×10-16) than pathology alone (p = 1.3×10-9). Cluster M1, characterized by high levels of methylation across almost all probes, was enriched for the rarer EOC subtypes; cluster M2, characterized by moderate levels of methylation across 50%-75% of probes, was predominantly HGSC. These patterns were observed irrespective of histology assignment strategy; however, when using histology by pathologist, cluster M2 had more endometrioid and LGSC tumors interspersed with HGSC tumors. Clustering based on expression data also produced two clusters. PathIHC produced slightly more homogenous clusters (p = 9.0×10-11, pathology alone, p = 2.3×10-10). Cluster E1 was enriched for the rarer EOC subtypes; cluster E2 was primarily serous lineage tumours (HGSC and LGSC), particularly when using histology by pathIHC. Considering only clinical outcomes, histologies by pathology were more significantly different in terms of TTP (p = 1.1×10-6) and TTD (p = 1.7×10-3) than histologies by pathIHC (TTP, p = 5.4×10-6; TTD, p = 5.7×10-3). Conclusions: Histology by pathIHC produced more homogeneous clusters in both the methylation and expression data; thus, molecular data supports this strategy. Differences in clinical outcomes (TTP and TTD) between histology groups were more pronounced when using assignment by pathologist; thus, clinical data supports this strategy. Citation Format: M A. Earp, S J. Winham, S M. Armasu, B L. Fridley, M C. Larson, Z C. Fogarty, K R. Kalli, C Wang, G L. Keeney, J M. Cunningham, S Ramus, M Kobel, E L. Goode. Comparison of pathology versus IHC-based ovarian carcinoma histology assignment using gene expression, DNA methylation, and clinical outcome data. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4246. doi:10.1158/1538-7445.AM2015-4246

Infiltrating hybrid mesenchymal tumor of skeletal muscle showing lipomatous, hemangiomatous, leiomyomatous and osseous features – An unusual soft tissue tumor providing insight into the pathogenesis of lipoma variants

Infiltrating angiolipoma and osteolipoma of the hand are rare. A 40-year-old man presented with slowly enlarging swelling of his right hand for two and half years without functional deficit but it became painful with slight limitation of movement for the past few months. Plain radiograph showed a large soft tissue swelling with specks of calcifications. Ultrasonography and magnetic resonance imaging revealed an infiltrative mass in the right palm deep to the flexor tendons. As biopsy suggested infiltrative angiolipoma of skeletal muscle, debulking of the tumor was performed. The tumor showed coexistence of all four mesenchymal elements, fat, blood vessel, smooth muscle and bone in various combinations in the form of angiolipomatous, osteolipomatous, ossified intramuscular hemangiomatous, myolipomatous and angiomyolipomatous patterns throughout the entire tumor. Small meningothelial-like whorls of spindle cells were focally seen, some showed intramembranous ossification forming small woven bony spicules in their centers. There were no atypical cells or lipoblasts. Staining for CDK4, MDM2, p16, HMB45 and Melan A was negative. The diagnosis was “infiltrating hybrid mesenchymal tumor of skeletal muscle showing lipomatous, hemangiomatous, leiomyomatous and osseous features”. The fairly even admixture of the various components supports the neoplastic participation of each individual element. Hybrid mesenchymal tumor most probably originates from multipotent neoplastic cells showing multidirectional differentiation.

A confirmatory approach to diagnosing well-differentiated liposarcoma using limited biopsy tissue

Aim To demonstrate a confirmatory approach to diagnosing a well-differentiated liposarcoma using limited biopsy tissue. Methods A 66-year-old man presenting with pneumonia had an incidental CT finding of a 20 cm heterogeneous fat-density mass within the central mediastinum. The mass showed low PET FGD-avidity. The radiological characteristics and location suggested a liposarcoma. Mediastinoscopic biopsy yielded limited lesional tissue, further analysed by light microscopy on H&E and IPX stains, and FISH analysis for MDM2-gene amplification. Results Microscopically, the lesional tissue resembled an adipocytic lesion comprising mature adiopocytes with significant variability, nuclear atypia, with occasional lipoblasts, and fibromyxoid stroma. However, necrosis, mitosis and dedifferentiated areas were not identified. The lesional cells showed positive staining for MDM2 and negative staining for CD34, S-100, HMB45, cytokeratins and calretinin. FISH analysis revealed MDM2-gene amplification, confirming the diagnosis of a well-differentiated liposarcoma. Dedifferentiated areas were identified on subsequently resected tumour. Discussion The diagnosis of well-differentiated liposarcoma on biopsy is sometimes difficult with limited and poorly representative tissue. Whilst location and radiological appearance may be suggestive, a selective IPX panel and MDM2 FISH analysis can offer a definitive diagnosis.

Absence of chromosomal abnormalities in herniated orbital fat

Lipomatous tumours of the orbit are rare, and can sometimes be difficult to characterize. Herniated orbital fat is thought to be a reactive process, but its presentation can mimic a lipomatous tumour such as an atypical lipomatous tumour or spindle cell/pleomorphic lipoma. Genetic studies to determine if it is indeed a reactive process rather than an adipocytic neoplasm have not been performed. Four samples of herniated orbital fat were reviewed clinically, histopathologically and immunohistochemically. Array comparative genomic hybridization (aCGH) was used to search for genome-wide copy number alterations within the tumours. Histological evaluation revealed that all four tumours contained collections of adipocytes surrounded by fibrous septae. Lochkern cells and floret-like multinucleated giant cells were present, consistent with herniated orbital fat. CD34 was positive in all tumours. Staining for MDM2 and CDK4 was negative. ACGH analysis demonstrated no copy number alterations. Herniated orbital fat may share some histopathological features with lipoma and atypical lipomatous tumour, but the absence of copy number gains or losses is consistent with the impression that herniated orbital fat is a reactive process. Genetic analysis may be another method to help differentiate herniated orbital fat from a lipomatous orbital tumour when the diagnosis is in question.

Interaction between p53 and MDM2 in Human Lung Cancer

The oncoprotein p53 protein induces cell growth arrest (apoptosis) in response to endo or exogenous stimuli. Mutation of TP53 (gene encoding the p53 protein) is common in human malignancies and alters the conformation of p53. The result is a more stable protein which accumulates in nuclei of tumor cells with loss of function. Mutant p53 is stabilized, and it is possible to detect this form very clearly by immunohistochemistry (IHC). Expression of the MDM2 protein is used as a potential marker of p53 function. P53 levels in normal cells are highly determined by the MDM2 protein (murine double minute 2) - mediated degradation of p53. MDM2 overexpression represents at least one mechanism by which p53 function can be abrogated during tumorigenesis. Lung carcinoma samples were obtained from patients, who underwent radical resection (lobectomy or pulmonectomy and lymphadectomy). Pathological dia-gnosis was based on the WHO criteria. In our study, we investigated the expression of p53 and MDM2 protein that might improve IHC as a marker for p53 status. Proteins were IHC detected in 136 samples of primary lung carcinoma. Immunostaining results of p53 positive samples were compared to IHC expression of MDM2 positive and MDM2 negative samples. Strong brown nuclear staining was visible in p53 and MDM2 positive cells. The most p53 positive cases were samples of squamocellular carcinoma (55%), then samples of large cell carcinoma (53%) and 26% adenocarcinoma samples showed the p53 immunoreactivity. No one sample of different types was p53 positive. When we compared the p53 expression and grade of tumor, we found that the p53 expression increased with the grade of tumor. For statistical evaluation, the chi square test was used. The relationship between p53 expression and type of tumor, also the p53 expression and grade of tumor was statistically significant (p = 0.000425; p = 0.00157). Regarding p53 and MDM2 expression, only nine samples (7%) were simultaneously p53 and MDM2 positive. In 46 (34%) cases, elevation of p53 was combined with MDM2 negative expression. Other tumor samples were either negative for both proteins (71/ 52%), or p53 negative and MDM2 positive in 10 (7%) tumor samples. Absence of p53 staining in most studies indicates absence of p53 mutation, and on the contrary, positive expression of p53 is a sign of p53 mutations with loss of function. In our study, 34% of cases with extensively high level of p53 without increased level of MDM2 were identified. We suppose that these are tumors with inactivating mutations that stabilize p53. On the other hand, tumors with high level of stabilized wildtype p53 protein and simultaneously with increased MDM2 staining (9 samples/7%) represent group with functional p53. In this group of patients, we could expect better prognosis with regard to function of p53 protein.

Paratesticular dedifferentiated liposarcoma with leiomyosarcomatous differentiation: a case report with a review of literature

Paratesticular liposarcoma is a rare neoplasm, described in single case studies or components of larger studies, as histologically well-differentiated liposarcoma (WDL) and dedifferentiated liposarcoma (DL). However, leiomyosarcomatous differentiation is an extremely rare occurrence in WDL and DL. We report a case of leiomyosarcomatous differentiation in a 77-year-old man. The patient presented with a painless right scrotal mass. Magnetic resonance imaging showed a large mass along the right spermatic cord. The resected mass, measuring 17.5 × 12 × 5 cm, was composed of a high-grade pleomorphic undifferentiated sarcomatous component with necrosis. Atypical smooth muscle differentiation was also detected. Additional tumor sampling revealed the presence of a WDL component. Immunohistochemical analysis of the pleomorphic sarcomatous component showed positive staining for MDM2 and CDK4, and negative staining for alpha smooth muscle actin (αSMA) and desmin. The smooth muscle component was positive for αSMA and desmin, and negative for MDM2 and CDK4. Extension from primary retroperitoneal sarcoma was not proved. We diagnosed of DL with leiomyosarcomatous differentiation.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1484291498104021.

The P53 Pathway Is Inactive in Acute Myeloid Leukemia

Abstract 5122The pathway controlled by the p53 tumor-suppressor protein is altered in most, if not all, human cancers and the TP53 gene is mutated in half of all human tumors. Such mutations are rare in human hematological malignancies, leading to the assumption that the p53 pathway is inactivated by alternative mechanisms. However, to date, the state of activity of the p53 pathway in hematological malignancies is not well understood. We investigated the functional status of the p53 pathway in Acute Myeloid Leukemia (AML) patients, particularly in patients with cytogenetically normal AML (CN-AML) and patients with Acute Promyelocytic Leukemia (APL).We performed bioinformatic analysis of p53 pathway-related gene expression. For this purpose, we first assembled a list that, to the best of our knowledge, is the most comprehensive list to date of genes related to the p53 pathway. The list consists of 1153 p53 pathway-related genes: 916 p53-related genes and 582 partially overlapping genes related to important components of the p53 pathway (Mdm2, Mdmx, Puma, Slug and Chk2). The list of p53 pathway-related genes was constructed based on gene and protein web databases and literature search. Only genes with proven biochemical relationships to the p53 pathway were included.Publically available Affymetrix gene expression array data was analyzed which included 290 CN-AML and 34 APL patients at diagnosis in comparison to 63 normal bone marrow (nBM) samples. Differentially expressed genes (DEGs) were identified out of 1153 p53 pathway-related genes using a linear statistical model that produced gene expression contrasts between leukemic samples and nBM. Study effect differences were also corrected by this model. One hundred forty seven DEGs were identified in CN-AML and 172 in APL (fold change>2. 8, p value<0. 01). We found a significant over-representation of p53 pathway related DEGs above the genomic background in both leukemias. Our analysis demonstrated homogeneity of gene expression in APL patients and discovered that CN-AML patients were further divided into 3 sub-groups by hierarchical clustering analysis. Most of the DEGs were down regulated both in CN-AML (108/147) and in APL (135/172) patients. We analyzed the DEGs and concluded that in both leukemias there was no p53-dependent induction of canonical cell cycle arrest genes, canonical pro-apoptotic genes, p53-related antioxidant defense genes, DNA damage repair genes and anti-glycolysis genes.We compared our bioinformatic results to gene expression signatures related to p53 activation by various stimuli from the literature. This analysis demonstrated that p53 protein did not exert transcriptional activation of the majority of its target genes in CN-AML and APL, implying that p53 pathway is not activated in these leukemias.We found downregulation of p300, PCAF and CARM1 genes in patient samples compared to nBM. Deregulation of these genes points to decreased acetylation and methylation of the p53 protein that can result in the inhibition of p53 transcriptional activity.We examined protein levels of p53 and its main inhibitors Mdmx and Mdm2 by immunohistochemistry in 25 CN-AML and 23 APL patients in comparison to 36 nBM biopsies. We found that the fraction of cells expressing p53, Mdmx and Mdm2 proteins was significantly higher in leukemias (70–90%) compared to nBM (10–30%). However, the intensity of Mdm2 staining was not elevated in leukemic blasts compared to nBM and p53 levels were similarly low in both nBM and leukemias. Importantly, Mdmx protein level was significantly upregulated in leukemia cells, offering an explanation for inhibition of p53 transcriptional activity in leukemia. The increased level of Mdmx protein together with low levels of p53 protein is in agreement with inhibition of p53 transcriptional activity in CN-AML and APL demonstrated by our bioinformatic analysis.Inactivation of p53 pathway shown here may be one of the important leukomogenic events in AML development. Importantly, gene expression and thus the functional status of p53 pathway is very similar in CN-AML and APL patients compared to nBM, despite the different underlying molecular etiology of these diseases. This finding may have important therapeutic implications in that similar reactivation of the p53 pathway may be a therapeutic modality applicable to these two biologically different types of leukemia. Disclosures:No relevant conflicts of interest to declare.

Well‐differentiated and dedifferentiated liposarcomas with prominent myxoid stroma: analysis of 56 cases

Occasional cases of well-differentiated and dedifferentiated liposarcoma (LPS) contain myxoid stroma, leading to confusion with other sarcomas. The aim of this study was to analyse the clinicopathological and genetic features of well-differentiated/dedifferentiated LPS with prominent myxoid stroma. Fifty-six cases of LPS (22 well-differentiated; 34 dedifferentiated) with prominent myxoid stroma were evaluated. Most arose in the retroperitoneum, abdominal cavity, or spermatic cord. The mean size was 170 mm. Myxoid LPS-like plexiform vessels were conspicuous in 11 cases of well-differentiated LPS. In 22 cases of dedifferentiated LPS, myxofibrosarcoma-like curvilinear vessels were prominent. In other cases, the myxoid component had variably bland or pleomorphic morphology. By immunohistochemistry, staining for MDM2 was positive in 95% of cases, and CDK4 in 78%. Cytogenetics in 13 cases showed ring and giant marker chromosomes. Fluorescence in-situ hybridization showed amplification of 12q13-15 in six cases evaluated. Of 30 patients with follow-up, all but one had local recurrences (up to four), but only one has so far had distant metastases. Well-differentiated/dedifferentiated LPS with prominent myxoid stroma can closely resemble other sarcoma types, especially myxoid LPS and myxofibrosarcoma. The clinical presentation (large retroperitoneal or abdominal tumour) is a clue to the correct diagnosis; the degree of nuclear atypia helps to exclude myxoid LPS. Immunohistochemistry for MDM2 and CDK4 and genetic analysis can be useful to confirm the diagnosis.

Cervical Dedifferentiated Liposarcoma with Meningothelial-Like Whorling

Liposarcomas are the most common soft-tissue sarcoma of adults, but rare in the head and neck. Recently, a subtype of dedifferentiated liposarcoma with meningiothelial-like whorls was reported and we present the first description of such a tumor in the head and neck. A 65year old male underwent a resection of a calcified retroesophageal mass that was in close relation to the left hemithyroid and recurrent laryngeal nerve. It was resected en bloc with the left thyroid lobe. Initial pathologic evaluation suggested the mass was a schwanomma of the recurrent laryngeal nerve, but positive staining for MDM2 and CDK4 indicated the tumor was a dedifferentiated liposarcoma. Further evaluation elucidated the unique meningothelial-like whorls within the tumor. This case demonstrates dedifferentiated liposarcomas do appear in the head and neck. Furthermore, this is the first report in the head and neck of the mengiothelial-like whorling pattern type of dedifferentiated liposarcoma.

Evaluation of MDM2, p16, and p53 staining levels as biomarkers of biochemical recurrence following salvage radiation therapy for recurrent prostate cancer

The selection of appropriate candidates for salvage radiation therapy (SRT) to address a rising PSA following radical prostatectomy remains challenging. Herein, we provide the first evaluation of the ability of staining levels of the tumor based biomarkers MDM2, p16, and p53 to aid in prediction of biochemical recurrence (BCR) among men undergoing SRT for recurrent prostate cancer. We identified 152 patients who were treated with SRT between July 1987 and July 2003. Staining levels of MDM2, p16, and p53 in primary tumor samples removed during prostatectomy were detected using monoclonal antibodies and quantified by use of a computer-assisted method. Associations of staining levels with BCR were evaluated using Cox proportional hazards regression models; relative risks (RRs) and 95% confidence intervals (CIs) were estimated. Compared to patients with low staining (≤median) as measured by percentage of cells with nuclear staining, there was no significant difference in risk of BCR for patients with high MDM2 staining (RR: 0.90, 95% CI: 0.57-1.45, P = 0.67), high p16 staining (RR: 0.88, 95% CI: 0.54-1.44, P = 0.62), or high p53 staining (RR: 1.33, 95% CI: 0.84-2.11, P = 0.23) in multivariable analysis. These results were consistent when considering alternate percentile cutpoints and alternate quantifications of biomarker staining. Our results provide evidence that MDM2, p16, and p53 staining levels are not useful in the prediction of BCR after SRT. As such, these biomarkers are of little clinical use in the selection of appropriate candidates for SRT.

Secretory Carcinoma of Breast Demonstrates Nuclear or Cytoplasmic Expression in p63 Immunohistochemistry

The aim of this study was to evaluate the pattern of p63 expression and its implication in secretory carcinoma of the breast. Immunohistochemical staining for p63, p53, MDM2, and smooth muscle actin was performed in 7 cases of secretory carcinomas. Nuclear expression of p63 was observed in 3 cases, whereas staining against cytoplasmic and intraluminal secretory material were observed in 4 cases. p53 was expressed in 3 cases and MDM2 in 2 cases. The loss of myoepithelial cells was confirmed by immunohistochemical stain for smooth muscle actin in invasive secretory carcinomas. The pattern of expression of p63 in secretory carcinoma of the breast was revealed in nuclei or cytoplasm/secretory materials.

Critical histopathological analysis of 25 dedifferentiated liposarcomas, including uncommon variants, reviewed at a Tertiary Cancer Referral Center

De-differentiated liposarcomas (DDLSs) are uncommon tumors with a wide histopathological spectrum. Over an 8-year period (2003-2011), 25 DDLSs, after review, were critically analyzed for histopathological features. Twenty-five tumors, in 14 men and 11 women (M: F = 1.2:1), with age range of 22-88 years (mean, 53.9), occurred in retroperitoneum (14) (56%), thigh (3) (12%), paratesticular region (3) (12%), chest wall (2) (8%), leg (1) (4%), shoulder (1) (4%), and groin (1) (4%). Tumor size (21 tumors) varied from 7.5 to 25 cm (mean, 17.5). Histopathologically, DD component was high grade in 19 (76%) and low grade in 6 (24%) tumors. Whereas the most common WD component was adipocytic type; the most common DD component was pleomorphic sarcomatous (13) (52%), followed by myxofibrosarcomatous (MFS)-type (6) (24%). Low-grade DD components included MFS (2), fibrosarcoma (2), myogenic/myofibroblastic type (1), and IMFT-type (1). Three tumors displayed meningothelial-like whorls and metaplastic bone formation. Heterologous elements, noted in 11 (44%) tumors, included bone (8) and rhabdomyoblastic differentiation (2). Two tumors displayed homologous differentiation, reinforced with MDM2 staining. S100-P was diffusely positive in WD components (5/7) and focally in DD components (2/9). All patients were treated with surgery, including 10, who underwent adjuvant radiotherapy. Outcomes (16 patients, 64%), over 1-48 months included 10 patients free of disease, 4 died of disease, and 2 patients alive with disease. This study forms the largest documentation of DDLSs, including its wide histopathological spectrum, from our country. Rare cases overlap with pleomorphic liposarcoma. S100-P and MDM2 are useful in substantiating adipocytic differentiation, especially in selected cases. Analysis of adequate tumor sections is vital for correct identification of a DDLS. Surgical excision with adjuvant RT forms optimal treatment.

A study of proliferative markers and tumor suppressor gene proteins in different grades of ependymomas

Ependymomas are CNS tumors that originate from the spinal canal and walls of the ventricular system. Considerable controversy continues to exist with regard to their prognostic factors; age and extent of resection are the only statistically significant prognostic factors yet identified. The authors report a retrospective study of a homogenous population of 119 patients harbouring ependymomas between 1991 and 2002. All clinico-radiological and follow-up data were analyzed and a pathologic review was performed by two pathologists. Immunohistochemical staining for MIB-1, Topo IIalpha, p53 and MDM2 was performed. Histopathologic grades show relationship with MIB1 and Topo IIalpha labelling indices and cut-off values of 5% can differentiate between anaplastic and lower grades. p53 and MDM2 proteins expression are not common in ependymomas; however, they are seen in higher grades only and may be involved in the tumor progression.