The pathological features of 155 adult patients with soft-tissue sarcomas were studied retrospectively, in an attempt to set up a grading system for these tumors. As the first step, seven histological criteria (tumor differentiation, cellularity, importance of nuclear atypia, presence of malignant giant cells, mitosis count, pattern of tumor necrosis and presence of vascular emboli) were evaluated in a monofactorial analysis. Five of these (tumor differentiation, cellularity, mitosis count, tumor necrosis, and vascular emboli) were correlated with the advent of metastases and with survival. A multivariate analysis, using a Cox model, selected a minimal set of three factors (tumor differentiation, mitosis count, and tumor necrosis) the combination of which was necessary and sufficient to retain all the prognostic information. A grading system was elaborated, which turned out to be correlated with the advent of metastasis and with patients' survival. A second multivariate analysis introducing clinical prognostic features showed that the histological grade was the most important prognostic factor for soft-tissue sarcomas. Thus, this grading system appears to be highly interesting because of its prognostic value and the facility of its elaboration. However, its reproducibility should be tested.

Tumor grade has been proposed as an essential factor in the staging of patients with soft tissue sarcomas. In a previous study, a histopathologic grading system using the evaluation of tumor differentiation, mitosis count, and tumor necrosis was described. The current study was conducted to test its reproducibility. The pathologic sections of 25 soft tissue sarcomas were submitted to a study group composed of 15 pathologists who had not been involved in the development of the grading system. The results were compared with those of a panel group. The crude proportion in agreement observed between the study group and the panel group was 81% for the evaluation of tumor necrosis, 74% for tumor differentiation, and 73% for the mitosis count. The crude proportion in agreement for the tumor grade was 75%, which was significantly better than the crude agreement rate of 61% for the diagnosis of histologic type (P = 0.001). A kappa statistical analysis, to check the possibility of chance-related concordance, showed a proportion in agreement of 68%. A two-way variance analysis showed that the homogeneity of the evaluation of tumor grade is impaired by tumor-related and observer-related factors. However, an improvement may be obtained by better training of pathologists. We conclude that the tumor grading system developed inside the French Federation of Cancer Centers, although perfectible, already provides reliable prognostic information and its use in prospective clinical studies may provide more information about its clinical usefulness.

Purpose To prospectively assess the clinical impact of expert review of lymphoma diagnosis in France. Materials and Methods From January 2010 to December 2013, 42,145 samples from patients with newly diagnosed or suspected lymphomas were reviewed, according to the 2008 WHO classification, in real time by experts through the Lymphopath Network. Changes in diagnosis between referral and expert review were classified as major or minor according to their potential impact on patient care. Results The 42,145 reviewed samples comprised 36,920 newly diagnosed mature lymphomas, 321 precursor lymphoid neoplasms, 314 myeloid disorders, and 200 nonhematopoietic neoplasms, with 4,390 benign lesions. There were 4,352 cutaneous and 32,568 noncutaneous lymphomas. The most common mature noncutaneous lymphomas were diffuse large B-cell lymphomas (32.4%), follicular lymphomas (15.3%), classic Hodgkin lymphomas (13%), peripheral T-cell lymphomas (6.3%) of which angioimmunoblastic T-cell lymphomas (2.3%) were the most frequent, and mucosa-associated lymphoid tissue lymphomas (5.8%). A diagnostic change between referral and expert review occurred in 19.7% of patients, with an estimated impact on patient care for 17.4% of patients. This rate was significantly higher for patients sent with a provisional diagnosis seeking expert second opinion (37.8%) than for patients sent with a formal diagnosis (3.7%). The most frequent discrepancies were misclassifications in lymphoma subtype (41.3%), with 12.3% being misclassifications among small B-cell lymphoma entities. Fewer than 2% of changes were between benign and malignant lymphoid conditions. Minor changes (2.3%) mostly consisted of follicular lymphoma misgrading and diffuse large B-cell lymphoma subtype misclassification. Conclusion To our knowledge, this study provides the largest ever description of the distribution of lymphoma entities in a western country and highlights how expert review significantly contributes to a precise lymphoma diagnosis and optimal clinical management in a proportion of patients.