title: [Clinicopathologic study of 40 cases of mediastinal tumours of haematopoietic and lymphoid tissues].
abstract: OBJECTIVE
  To study clinical and histopathological features, and diagnosis of mediastinal tumours of haematopoietic and lymphoid tissues (MTHL).
  
  
  METHODS
  Forty cases of MTHL were analyzed for clinicopathology by microscopy and immunohistochemical staining and in situ hybridization, according to the updated 2008 WHO classification of tumours of haematopoietic and lymphoid tissues.
  
  
  RESULTS
  In 40 cases of MTHL, there were 20 males and 20 females. The ratio of male/female was 1:1. The mean age was 31.8 years and median age was 29 years (range, 12 - 70 years).Superior vena cava syndrome was observed in 28 cases. The specimens of 4 cases were obtained by lumpectomy, whereas 36 cases by biopsy (25 cases by thoracoscopy, 1 by core needle aspiration). Twenty cases lay in anterior mediastinum, and 2 in posterior, 1 in superior, 8 in anterior and superior, 2 in posterior and superior, 2 in anterior and middle, 1 in middle and anterior mediastinum.Frozen section were performed in 28 cases, and 17 cases were diagnosed as tumours of haematopoietic and lymphoid tissues (consistency ratio was 60.7%). Twelve cases were classical Hodgkin lymphomas (cHL) (8 were nodular sclerosis subtype, and 3 were mixed cellarity, 1 was lymphocyte-rich subtype), and 10 were primary mediastinal (thymic) large B cell lymphoma (PMBCL), 10 were precursor lymphocyte neoplasm [8 were T lymphoblastic leukemia/lymphomas (T-LBL), 2 were B-LBL], 1 was MALT lymphoma, 1 was composite lymphoma (PMBCL and cHL), 2 were myeloid sarcomas, 4 were gray zone lymphomas (GZL) (3 had morphology reminiscent of cHL, and 1 of DLBCL, all cases were positive for CD20, PAX5, CD30 and CD15).EBER were detected in 11 cases by in situ hybridization, 2 of which were positive (18.2%), and the 2 positive cases were cHL.
  
  
  CONCLUSIONS
  MTHLs occur predominantly in adolescents and young adults, mainly present as superior vena cava syndrome and anterior mediasinal masses. cHL, PMBCL, T-LBL were the most common MTHLs.GZLs mainly occur in young adults, those whose morphology reminiscent of cHL, immunohistochemistry reminiscent of PMBCL, and vice versa. Thoracoscopy, frozen section and a suitable panel of antibodies were practical approaches to MTHL.
authors.affiliation: Department of Pathology, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Ding-bao
authors.initials: DB
authors.lastname: Chen
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Qiu-jing
authors.initials: QJ
authors.lastname: Song
authors.forename: Dan-hua
authors.initials: DH
authors.lastname: Shen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018951:Antigens, CD20 / Q000378:metabolism; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006689:Hodgkin Disease / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D017730:Ki-1 Antigen / Q000378:metabolism; D016256:Lewis X Antigen / Q000378:metabolism; D016393:Lymphoma, B-Cell / Q000378:metabolism / Q000473:pathology*; D018442:Lymphoma, B-Cell, Marginal Zone / Q000378:metabolism / Q000473:pathology; D008297:Male; D008479:Mediastinal Neoplasms / Q000378:metabolism / Q000473:pathology*; D008875:Middle Aged; D051757:PAX5 Transcription Factor / Q000378:metabolism; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism / Q000473:pathology*; D054218:Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism / Q000473:pathology*; D012189:Retrospective Studies; D013479:Superior Vena Cava Syndrome / Q000378:metabolism / Q000473:pathology; D015996:Survival Rate; D055815:Young Adult
chemical_list: D018951:Antigens, CD20; D017730:Ki-1 Antigen; D016256:Lewis X Antigen; D051757:PAX5 Transcription Factor; C497281:PAX5 protein, human