A new technique for the diagnosis of mycetoma using fixed blocks of aspirated material.

The aim of this prospective study was to evaluate the use of the cell block technique as a safe, accurate and quick tool for the cytodiagnosis of mycetoma. The study included 240 patients with suspected mycetoma. The suspected lesion was aspirated and the aspirated material was processed to form cell blocks. The cell blocks were processed as described for routine tissue histopathological examination. Haematoxylin/eosin-stained sections were reviewed to identify the morphological features of the mycetoma grains and the different inflammatory tissue reactions. The findings were compared with those seen in histopathological sections. The different mycetoma grains showed distinct morphological features on the cell block that were identical to those seen in histopathological sections. Distinction between eumycetoma and actinomycetoma and their classification according to the causative agent were possible. The cell block technique had sensitivities of 87.5% and 85.7% for eumycetoma and actinomycetoma, respectively, and there were no statistical differences in the findings obtained by the cell block and histopathological techniques. The technique is simple, rapid, specific, sensitive and inexpensive. It can be used in the routine diagnosis of mycetoma and to obtain grains for culture identification. The cell blocks can be preserved for a long period for future studies.