Cytology and clinical features of myelomatous pleural effusion: Three case reports and a review of the literature

The purpose of this study was to report the clinical features, laboratory findings, and cytomorphology, and prognosis of three patients with myelomatous pleural effusion (MPE). The literature pertaining to MPE was reviewed. The three cases and literature review suggest that MPE is rare and often associated with a poor prognosis. The correct diagnosis depends on the aggressive clinical characteristics, laboratory findings, and chromosomal abnormalities, but routine pathological examination of the pleural effusion has low sensitivity. Cell blocks stained with hematoxylin & eosin and by immunohistochemistry revealed that abnormal proliferation of plasma cells and light chain restrictive expression in MPE may be helpful for improving the detection rate of MPE.