Chylous effusion appears opaque, white to pink, protein is >2.5 g/dL, nucleated cell count is variable and predominantly small lymphocytes.
Exudates are turbid to opaque and have some color, protein >2.5 g/dL, and >5,000 cells/mcL that may be predominantly neutrophils or a mixture of inflammatory cells.
Hemorrhagic effusions are cloudy to opaque and red, with protein increased and equal to that of peripheral blood, variable nucleated cell counts, and no evidence of inflammation or neoplasia.
Modified transudates are slightly cloudy, have protein of 2.5–5.0 g/dL, and cell counts of 1,000–5,000/mcL, with variable types of inflammatory cells.
Neoplastic effusions are clear to slightly cloudy, have protein <2.5 and total cell counts of <1,000, and contain clusters of neoplastic cells.
Transudate appears slightly cloudy, protein is <2.5 g/dL, nucleated cell count is <1,500 cells/mcL, and predominant cells are neutrophils.