title: Pyothorax-associated lymphoma: a review of 106 cases.
abstract: OBJECTIVE
  Pyothorax-associated lymphoma (PAL) is a non-Hodgkin's lymphoma developing in the pleural cavity after a long-standing history of pyothorax. Full details of PAL are provided here.
  
  
  METHODS
  Clinical and pathologic findings were reviewed in 106 patients with PAL collected through a nationwide survey in Japan.
  
  
  RESULTS
  Age of the patients with PAL was 46 to 82 years (median, 64 years), with a male/female ratio of 12.3:1. All patients had a 20- to 64-year (median, 37-year) history of pyothorax resulting from artificial pneumothorax for treatment of pulmonary tuberculosis (80%) or tuberculous pleuritis (17%). The most common symptoms on admission were chest and/or back pain (57%) and fever (43%). Laboratory data showed that the serum neuron-specific enolase level was occasionally elevated (3.55 to 168.7 ng/mL; median, 18.65 ng/mL), suggesting a possible diagnosis of small-cell lung cancer. Histologically, PAL usually showed a diffuse proliferation of large cells of B-cell type (88%). In situ hybridization study showed that PAL in 70% of the patients was Epstein-Barr virus (EBV)-positive. PAL was responsive to chemotherapy, but the overall prognosis was poor, with a 5-year survival of 21.6%.
  
  
  CONCLUSIONS
  This study established the distinct nature of PAL as a disease entity. PAL is a non-Hodgkin's lymphoma of exclusively B-cell phenotype in the pleural cavity of patients with long-standing history of pyothorax, and is strongly associated with EBV infection. Development of PAL is closely related to antecedent chronic inflammatory condition; therefore, PAL should be defined as malignant lymphoma developing in chronic inflammation.
authors.affiliation: Department of Pathology, Osaka University Graduate School of Medicine, Suita, Japan.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Nakatsuka
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yao
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Hoshida
authors.forename: Satoru
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Keiji
authors.initials: K
authors.lastname: Iuchi
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Aozasa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D016724:Empyema, Pleural / Q000150:complications* / Q000209:etiology; D020031:Epstein-Barr Virus Infections / Q000150:complications; D005260:Female; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000145:classification / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010997:Pleural Neoplasms / Q000145:classification / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D011031:Pneumothorax, Artificial / Q000009:adverse effects; D016019:Survival Analysis; D014396:Tuberculosis, Pleural / Q000150:complications