title: [Histopathology and prognosis of thymomas. Statistical analysis of 200 cases].
abstract: 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)
authors: Service d'Anatomie Pathologique, Centre Chirurgical Marie-Lannelongue, Le Plessis-Robinson.
authors: J M
authors: JM
authors: Verley
authors: D
authors: D
authors: Silbert
authors: K H
authors: KH
authors: Hollmann
authors: P
authors: P
authors: Levasseur
mesh_terms: D000708:Anaplasia / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D006801:Humans; D007633:Keratins; D008214:Lymphocytes / Q000473:pathology; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D013945:Thymoma / Q000145:classification / Q000401:mortality / Q000473:pathology*; D013953:Thymus Neoplasms / Q000145:classification / Q000401:mortality / Q000473:pathology*
chemical_list: D007633:Keratins
vernacular_title: Histopathologie et pronostic des thymomes. Analyse statistique de 200 cas.