Classification and subtype prediction of adult soft tissue sarcoma by functional genomics

Adult soft tissue sarcomas are a heterogeneous group of tumors, including well-described subtypes by histological and genotypic criteria, and pleomorphic tumors typically characterized by non-recurrent genetic aberrations and karyotypic heterogeneity. The latter pose a diagnostic challenge, even to experienced pathologists. We proposed that gene expression profiling in soft tissue sarcoma would identify a genomic-based classification scheme that is useful in diagnosis. RNA samples from 51 pathologically confirmed cases, representing nine different histological subtypes of adult soft tissue sarcoma, were examined using the Affymetrix U95A GeneChip. Statistical tests were performed on experimental groups identified by cluster analysis, to find discriminating genes that could subsequently be applied in a support vector machine algorithm. Synovial sarcomas, round-cell/myxoid liposarcomas, clear-cell sarcomas and gastrointestinal stromal tumors displayed remarkably distinct and homogenous gene expression profiles. Pleomorphic tumors were heterogeneous. Notably, a subset of malignant fibrous histiocytomas, a controversialhistological subtype, was identified as a distinct genomic group. The support vector machine algorithm supported a genomic basis for diagnosis, with both high sensitivity and specificity. In conclusion, we showed gene expression profiling to be useful in classification and diagnosis, providing insights into pathogenesis and pointing to potential new therapeutic targets of soft tissue sarcoma.     

The rise and fall of malignant fibrous histiocytoma

The term malignant fibrous histiocytoma was coined by Stout and associates in the 1960s to encompass pleomorphic soft tissue sarcomas presumably derived from histiocytes that are capable of fibroblastic transformation. The concept was reaffirmed in the following 2 decades and malignant fibrous histiocytoma thus was regarded as the most common soft tissue tumor in older adults. However, recent more critical clinicopathologic, ultrastructural, and immunohistochemical studies have shown that malignant fibrous histiocytomas are not derived from histiocytic "facultative fibroblasts" and many neoplasms so diagnosed actually are pleomorphic subtypes of other sarcomas. Meticulous electron microscopic and immunohistochemical investigations also found that the more common storiform-pleomorphic, myxoid, and perhaps the giant cell subtypes are composed of variable mixtures of fibroblasts and phenotypically modulated fibroblastic cells, notably myofibroblasts and histiofibroblasts. On the basis of these findings, we propose a new classification for the above subtypes of so-called malignant fibrous histiocytoma, the majority of which are variants of pleomorphic fibrosarcoma.     

Case Report: Congenital Radioulnar Synostosis and Its Embryological Correlation and Functional Assessment

Congenital radioulnar synostosis(CRS) is a rare anomaly and approximately 400 cases were reported worldwide so far. CRS is the failure of the longitudinal segmentation and the persistence of the cartilaginous anlage between the radius and ulna during the seventh week of development that results in a persistent bridge of tissue. Here we are discussing on a case of 25yrs old, male patient with bilateral congenital synostosis. On the left hand the pronation and supination movements are restricted completely where as on right side 10 degree of supination and 20 degree of pronation is possible. Radiologically in our patient synostosis is classified as type II variety by Wilkie(1914)1 classification and type IV by the Cleary and Omer classification(1985). The position of forearm was not found to be related to subjective functional limitation, or employment status. Main line of treatment is surgical mainly rotational osteotomy but is rarely indicated. Our patient is not able to rotate his forearm especially on the left side still he has no functional limitation so he has refused for the operative treatment. No study has objectively compared the preoperative functional limitation of the patients with their postoperative functional improvement in order to justify surgical intervention In the authors opinion the only major factor that is to be taken into consideration of operative treatment is functional limitation to the patient.     

PLAG1 immunohistochemistry is a sensitive marker for pleomorphic adenoma: a comparative study with PLAG1 genetic abnormalities

Aims

Pleomorphic adenoma gene 1 (PLAG1) gene rearrangement is the most common genetic abnormality in pleomorphic adenoma (PA), resulting in overexpression of PLAG1 protein. PA and carcinoma ex pleomorphic adenoma (CA ex‐PA) can mimic various benign and malignant salivary gland tumours. The aims of this study are to evaluate the sensitivity and specificity of PLAG1 immunohistochemistry (IHC) in the differential diagnosis of PA and CA ex‐PA and to compare the PLAG1 immunohistochemical results to PLAG1 gene abnormalities as detected by fluorescence in‐situ hybridisation (FISH).

Methods and results

PLAG1 immunostaining was performed on 83 salivary gland tumours, including 23 PA, 15 CA ex‐PA and 45 other salivary gland tumours. In addition, PLAG1 FISH was performed in 44 cases for the presence of gene rearrangements/amplifications. The results showed high sensitivity of PLAG1 IHC in 96% of PA; however, discordant results between PLAG1 FISH abnormalities and IHC were noted in 15 of 44 cases (34%). Seven PA, four de‐novo myoepithelial carcinomas and one basal cell adenocarcinoma had negative FISH results, but were positive for IHC; while three salivary duct carcinomas (SDC) ex‐PA were positive for FISH but negative for IHC. PLAG1 IHC can differentiate CA ex‐PA from de‐novo SDC (P = 0.02), but not from de‐novo myoepithelial carcinoma. PLAG1 IHC is a sensitive marker for PA. This could be due to PLAG1 gene abnormalities beyond FISH resolution.

Conclusions

A negative PLAG1 IHC might be helpful in excluding a PA diagnosis. Interestingly, in the context of CA ex‐PA, FISH is more sensitive than IHC in detecting PLAG1 abnormalities.     

Diabetes Patients' Experiences With the Implementation of Insulin Therapy and Their Perceptions of Computer-Assisted Self-Management Systems for Insulin Therapy

Background

Computer-assisted decision support is an emerging modality to assist patients with type 2 diabetes mellitus (T2DM) in insulin self-titration (ie, self-adjusting insulin dose according to daily blood glucose levels). Computer-assisted insulin self-titration systems mainly focus on helping patients overcome barriers related to the cognitive components of insulin titration. Yet other (eg, psychological or physical) barriers could still impede effective use of such systems.

Objective

Our primary aim was to identify experiences with and barriers to self-monitoring of blood glucose, insulin injection, and insulin titration among patients with T2DM. Our research team developed a computer-assisted insulin self-titration system, called PANDIT. The secondary aim of this study was to evaluate patients’ perceptions of computer-assisted insulin self-titration. We included patients who used PANDIT in a 4-week pilot study as well as patients who had never used such a system.

Methods

In-depth, semi-structured interviews were conducted individually with patients on insulin therapy who were randomly recruited from a university hospital and surrounding general practices in the Netherlands. The interviews were transcribed verbatim and analyzed qualitatively. To classify the textual remarks, we created a codebook during the analysis, in a bottom-up and iterative fashion. To support examination of the final coded data, we used three theories from the field of health psychology and the integrated model of user satisfaction and technology acceptance by Wixom and Todd.

Results

When starting insulin therapy, some patients feared a lifelong commitment to insulin therapy and disease progression. Also, many barriers arose when implementing insulin therapy (eg, some patients were embarrassed to inject insulin in public). Furthermore, patients had difficulties increasing the insulin dose because they fear hypoglycemia, they associate higher insulin doses with disease progression, and some were ignorant of treatment targets. Patients who never used a computer-assisted insulin self-titration system felt they had enough knowledge to know when their insulin should be adjusted, but still believed that the system advice would be useful to confirm their reasoning. Furthermore, the time and effort saved with automated insulin advice was considered an advantage. Patients who had used PANDIT found the system useful if their glycemic regulation improved. Nevertheless, for some patients, the absence of personal contact with their caregiver was a drawback. While guidelines state that adjustment of basal insulin dose based on fasting plasma glucose values is sufficient, both patients who had and those who had not used PANDIT felt that such a system should take more patient data into consideration, such as lifestyle and diet factors.

Conclusions

Patients encounter multiple obstacles when implementing insulin therapy. Computer-assisted insulin self-titration can increase patient awareness of treatment targets and increase their confidence in self-adjusting the insulin dose. Nevertheless, some barriers may still exist when using computer-assisted titration systems and these systems could also introduce new barriers.     

Fibrosarcoma Mimicking Plasmacytoma or Carcinoma: An Ultrastructural Study of 4 Cases

Because the fibroblast has a remarkable capability of phenotypic modulations, reflected in both morphologic and immunohistochemical (IHC) changes, ultrastructural studiesare mandatory to identify the variants of fibroblasts. Myofibroblasts or histiofibroblasts are such examples, demonstrating chimeric ultrastructural features of fibroblastic cells in common with smooth muscle cells or with histiocytes, respectively. The presence of epithelioid fibroblastic cells sharing morphologic features with epithelial or plasma cells has not been yet characterized. The authors identified 4 cases of fibrosarcomas (FS) characterized by an unusual phenotype and associated with peculiar ultrastructural findings. The electron microscopic (EM) findings were correlated with the histologic appearance and immunoprofile. All tumors were located in the extremities, 3 in soft tissues and 1 in the bone. By light microscopy 2 cases were composed predominantly by round uniform cells with a striking plasmacytoid appearance. One case mimicked carcinoma, composed predominantly by epithelioid cells and scattered giant tumor cells. The fourth case showed a mixture of plasmacytoid-like and epithelioid cells. By IHC, tumor cells were positive for vimentin and in 2 cases also for epithelial membrane antigen. Kappa/lambda light chain and cytokeratins markers were negative. By EM all 4 tumors showed in addition to classic features of fibroblasts, unusual epithelial-type features, such as secretory granules of "neurosecretory-type" (3 cases), rudimentary cell junctions (3 cases), microvilli (2 cases), and lumen-like structures (1 case). One plasmacytoid-type tumor showed finely granular extracellular deposits. The study describe 4 examples of fibrosarcomas with unusual features at the ultrastructural level, which are associated microscopically with a peculiar phenotype, mimicking plasmacytoma or carcinoma. These findings broaden the spectrum of fibroblastic cell variants in neoplasia.