title: Thymoma: a pathological study of 50 cases.
abstract: BACKGROUND
  A combination of epithelial cells and lymphocytes results in a varied histomorphology of thymomas and consequent varied classification systems.
  
  
  OBJECTIVE
  To correlate the Marino and Muller-Hermelink (MMH) classification with the invasive behaviour of thymomas.
  
  
  METHODS
  Retrospective analysis.
  
  
  METHODS
  Thymomas encountered in the past 21 years were re-classified with the MMH classification and correlated with Masaoka's staging and clinical presentation.
  
  
  RESULTS
  The thymomas formed 91% of the primary thymic epithelial tumours. Predominantly cortical thymomas (n=21) and cortical thymomas (n=22) were the common subtypes and 60% and 77% of these, respectively, were in stages II or III. Cystic change, necrosis or haemorrhage played no role in predicting invasive behaviour. Cortical epithelium correlated well with the presence of para-thymic syndromes, especially myasthenia gravis.
  
  
  CONCLUSIONS
  MMH classification is easy to apply. Cortical thymomas in stage I should be followed up for possible recurrence.
authors.affiliation: Department of Pathology (Cardiovascular and Thoracic Division), Seth G. S. Medical College, Mumbai, India. shreeprajai@yahoo.co.in
authors.forename: Pradeep
authors.initials: P
authors.lastname: Vaideeswar
authors.forename: A
authors.initials: A
authors.lastname: Padmanabhan
authors.forename: J R
authors.initials: JR
authors.lastname: Deshpande
authors.forename: S P
authors.initials: SP
authors.lastname: Pandit
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D013945:Thymoma / Q000473:pathology*; D013953:Thymus Neoplasms / Q000473:pathology*