title: Cytopathological spectrum of unusual malignant pleural effusions at a tertiary care centre in north India.
abstract: BACKGROUND
  Cytological examination of pleural fluid is one of the most informative laboratory procedures in the diagnosis of pleural effusions. Although tuberculosis is the commonest cause of pleural effusions in developing countries, tumours, including grade ones, can present with effusions.
  
  
  OBJECTIVE
  The aim of the present study was to evaluate the uncommon causes of malignant pleural effusion.
  
  
  METHODS
  A 2-year retrospective analysis of pleural fluid cytological specimens submitted to the Department of Cytopathology, PGIMER, Chandigarh between January 2003 and December 2004 was performed to retrieve unusual metastases. Out of a total of 898 samples reviewed, 710 were negative for malignancy and 24 cases were suspicious for malignancy. The remaining 164 cases were positive for malignancy, out of which 38 cases revealed malignancies other than adenocarcinoma.
  
  
  RESULTS
  The 38 unusual malignancies metastasizing to the pleural cavity included 29 haematological malignancies (non-Hodgkin's lymphoma, acute lymphoid leukaemia, multiple myeloma and chronic myeloid leukaemia) and nine non-haematological malignancies (Ewing's sarcoma, neuroblastoma, Wilms' tumour, squamous cell carcinoma, small-cell carcinoma and malignant fibrous histiocytoma).
  
  
  CONCLUSIONS
  Although metastatic adenocarcinoma was the commonest aetiology of malignant pleural effusions, a significant number of unusual causes of malignant pleural effusion were also encountered.
authors.affiliation: Department of Cytopathology and Gynecological Pathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: A
authors.initials: A
authors.lastname: Awasthi
authors.forename: N
authors.initials: N
authors.lastname: Gupta
authors.forename: R
authors.initials: R
authors.lastname: Srinivasan
authors.forename: R
authors.initials: R
authors.lastname: Nijhawan
authors.forename: A
authors.initials: A
authors.lastname: Rajwanshi
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007194:India; D009369:Neoplasms / Q000175:diagnosis / Q000473:pathology*; D016066:Pleural Effusion, Malignant / Q000175:diagnosis / Q000473:pathology*; D012189:Retrospective Studies