[Histopathology and prognosis of thymomas. Statistical analysis of 200 cases]. / Histopathologie et pronostic des thymomes. Analyse statistique de 200 cas.

200 cases of thymoma operated on at the surgical centre of Marie-Lannelongue between 1955 and 1982 were reviewed and analysed statistically; their histology was compared and their evolutionary potential. Based on their degree of differentiation of the epithelial tumour component and on the proportion of non tumour associated lymphocytes, 4 histological types were defined: 1) Spindle-or-oval-cell thymomas where tumour cells reminiscent of normal involutive thymic cells were of small size with a tendency to form clusters, whorls or a glandular appearance; 2) Lymphocyte-rich thymomas where normal epithelial cells, few in number, reproduce the appearance of normal thymic cells; 3) Differentiated epithelial thymomas, comprised of large epithelial cells with abundant cytoplasm and clearly demarcated and often less numerous lymphocytes; 4) Undifferentiated epithelial thymomas, characterised by a poverty of lymphocytes and anaplastic epithelial cells with a raised nuclear cytoplasmic ratio, nuclear irregularity and mitosis. Statistically, there was a significant correlation between the degree of differentiation of the tumor and prognosis. Spindle-or-oval cell thymomas (type 1) and lymphocyte-rich thymomas (type 2) have an 80% survival at 5 years and a 75% survival at 10 years. Well differentiated epithelial thymomas of type 3 have a 75% survival at 5 years and a 50% survival at 10 years, finally undifferentiated epithelial thymomas (type 4); the survival rate was nil at 5 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Thymoma. A comparative study of clinical stages, histologic features, and survival in 200 cases.

Two hundred thymomas, surgically treated between 1955 and 1982 at the Marie Lannelongue Surgical Center, were subjected to statistical analysis, comparing clinical stages and histologic types and relating them to survival. Clinical stages were defined as follows. Stage I: no invasiveness, total excision; Stage II: localized invasiveness (no more than two mediastinal structures); Stage III: largely invasive, with or without distant tumorous grafts, lymph node deposits, or metastases. Four histologic types were retained: (1) spindle or oval cell type thymoma, (2) lymphocyte-rich thymoma, (3) differentiated epithelial thymoma, and (4) undifferentiated epithelial thymoma. Invasiveness remained a major prognostic factor, but the degree of invasion did not affect the survival rate or always justify radical surgery. Thus, the survival rate dropped from 85% at 5 years and 80% at 10 years in noninvasive tumors to 50% and 35%, respectively, in invasive tumors, but without significant difference between moderately invasive Stage II and largely invasive Stage III tumors. Histologic typing indicated a good correlation between the degree of differentiation of the tumors and prognosis. The survival rates were 80% at 5 years and 75% at 10 years for spindle cell type 1 and lymphocyte-rich type 2 thymomas, 75% at 5 years and 50% at 10 years for differentiated epithelial type 3, and nil at 5 years for undifferentiated type 4 thymomas. Although invasiveness often paralleled histologic typing, they appeared as two distinct parameters with separate prognostic significance, particularly in differentiated and undifferentiated epithelial tumors. One hundred five patients had myasthenia gravis and 14 had another autoimmune disease. The associated syndromes were no longer an adverse factor in the prognosis of thymoma.

[Ultrastructural study of small cell carcinoma (author's transl)]. / Diagnostic ultrastructural des cancers anaplasiques à petites cellules.

Fifty bronchopulmonary tumors were studied by light and electron microscopy: 39 carcinomas (25 small cell carcinomas, 8 undifferentiated carcinomas, 6 poorly differentiated squamous cell carcinomas) and 11 carcinoid tumors (5 central, 4 peripheral, 1 atypical, 1 of the tumorlet type). The results indicate that small cell carcinoma is a precise entity characterized by the presence of neurosecretory granules in the cytoplasm. Ultrastructurally carcinoid tumor resemble small cell carcinomas and there is a continuous spectrum of differentiation between the less undifferentiated neuro-endocrine tumors, i.e. the small cell anaplastic carcinomas, and the higher differentiated types, i.e. the carcinoids. The diagnostic and prognostic value of the ultrastructural findings are discussed.

Histopathological modifications following immunotherapy with P 40 in rats bearing DMBA-induced mammary carcinoma.

Female Sprague-Dawley rats bearing primarily-induced mammary carcinomas were treated with a new immunostimulating agent (P 40). The histopathological modifications encountered in tumors, lymph nodes, liver and spleen are described. Intratumoral injections provoke a more widespread response of the RES, and particularly a more intense reaction in the draining lymph nodes, than systemic treatment.

[Mammotropic and somatotropic pituitary cells in spontaneous mammary tumor bearing C3H female mice. A quantitative electron microscope study]. / Les cellules mammotropes et somatotropes de l'antehypophyse chez la souris C3H porteuse de tumeur mammaire spontanée. Etude quantitative au microscope électronique.

Pituitaries of mammary tumor-bearing mice (C3H) were examined by quantitative electron microscopy. The results indicate that considerable modifications occur in mammotropic and somatotropic cells. Both types show an increase of the surface of the endoplasmic reticulum and a decrease of the volume of secretory granules (in percent of cytoplasmic volume), suggesting a heightened secretory activity of these cells during mammary carcinogenesis.