a–d Conventional cytology (Pap stain and MGG stain) highlighting mesothelial cells filled up with LIs (yellow arrows) (×630, Pap (a); ×630, Pap (b); ×630, Pap (c); ×630, MGG (d)). Pap, Papanicolaou; MGG, May-Grünwald-Giemsa; LIs, lamellar inclusions.