Unilateral pleural effusion as a presenting manifestation of plasma cell myeloma (multiple myeloma): a case report.
BACKGROUND
Malignant pleural effusion caused by multiple myeloma (MM) is rare, occurring as a late complication with a poor prognosis. Myelomatous pleural effusion (MPE) as an initial manifestation of the disease is extremely uncommon.


METHODS
A 54-year-old, previously healthy man presented with right-sided pleural effusion. Cytologic examination of the aspirated fluid revealed large, slightly pleomorphic atypical cells, some having eccentric nuclei. Immunocytochemistry (ICC) performed on cytospin smears and cell block sections gave a positive reaction for CD138, EMA and vimentin and a negative reaction for CK7, CK20, calretinin, S-100 and E-cadherin.


CONCLUSIONS
Cytopathologists may be caught unawares by atypical presentations of hematologic malignancies. The diagnosis of MPE requires a high level of suspicion, and routine incorporation of ICC in the cytologic evaluation will ensure accurate diagnosis and proper patient management.
Cytopathology Unit, Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa, Israel. dharan_m@clalit.org.il
Muralee
M
Dharan
D017809:Fatal Outcome; D006801:Humans; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000150:complications / Q000175:diagnosis*; D010950:Plasma Cells / Q000473:pathology; D010996:Pleural Effusion / Q000150:complications / Q000175:diagnosis* / Q000473:pathology