AbstractTo evaluate a cell‐block preparation using glucomannan, which was extracted from Amorphophallus konjac. Ten specimens were centrifuged at 1,500 rpm for 5 minutes, the supernatant was removed; the remnant after the preparation of smear specimens for routine cytological examination was fixed with 20% formalin. The specimen was recentrifuged at 1,500 rpm for 5 minutes, and the supernatant was removed. The residue was resuspended with 2 ml of eosin solution and 1–5 ml of 80% alcohol, and stirred well. After further centrifugation, the supernatant was removed, and one drop of a glucomannan‐formalin water solution was added gently. After immersion in methanol for 2 hours, glucomannan is solidified and becomes gelatinous. The obtained cell block was placed in the cassette for the preparation of tissue specimens, dehydrated by the routine method, infiltrated with paraffin, and a paraffin‐embedded block was prepared. Thin sections were prepared from the paraffin‐embedded cell block, and hematoxylin–eosin (H&E) stain with immunological stains was performed. H&E stain, periodic acid‐Schiff reaction, Alcian blue, and immunohistochemical stain were clearly demonstrated.We evaluated a new modality of cell‐block preparation using a glucomannan‐formalin water solution. We found that the method was easy to perform and thought it could be useful as an alternative technique for cell‐block preparations. Thus, this novel technique should find wide application in the future. Diagn. Cytopathol. 2010;38:652–656. © 2009 Wiley‐Liss, Inc.