FISH analysis in cell touch preparations and cytological specimens from formalin-fixed fetal autopsies.

Postmortem studies on still-borns and miscarriages are important to define the sex and eventually the morphologic anomalies correlated to chromosomal aberrations. When the conditions for carrying out a cytogenetic study do not exist, these chromosomal alterations can be investigated by nucleic acid fluorescent in situ hybridization (FISH), which can be performed on interphase nuclei, usually on formalin-fixed paraffin embedded tissues or on fresh cytological specimens. The objective of the present study is to prove whether this technique can be successfully applied to formalin-fixed cell touch preparations and cytological specimens obtained from foetal autopsies. The study was carried out 12 abortions some of which were spontaneous and some of which were therapeutic. The materials were formalin-fixed. Cell touch preparations and cytological specimens were obtained. The FISH was performed using X/Y probes (Vysis) and the Aneuvysion Kit (05J38-030, Vysis), the probes being for chromosomes 13/21 and X/Y/18. To verify the reliability of the technique, the same reactions were also performed on fresh analogous materials. The slides were evaluable, and the probes hybridized to interphase nuclei showed distinct signals. All the samples were adequate for FISH analysis without any notable difference in the results. Moreover, it is technically possible to perform this analysis not only on fresh but particularly on formalin-fixed cytological specimens. On the other hand, the use of this type of cytological samples, as compared to formalin-fixed and paraffin embedded tissue sections, has the advantage of presenting intact, noncut nuclei with preserved cytomorphology, avoiding the problems of overlapping nuclei and making the identification of the real chromosomal arrangement easier.

Vegetable cells in Papanicolaou-stained cervical smears.

Vegetable cells are unusual findings in Papanicolaou-stained cervical smears; these structures could be wrongly mistaken for abnormal human cells, worm eggs, or spores by a cytologist encountering the possibility of meeting those elements in cytological analysis. Five cervicovaginal smears showing similar vegetable cells have been detected over a 3-yr period (2002-2004) in the course of a population screening program for cancer of the uterine cervix in Modena (Italy) involving 32,500 women. According to the clinical histories of the patients, the vaginal pharmaceutical drugs or appliances used were of different types: vaginal lavages, pessaries, and vaginal creams. Following a careful investigation, the only substance that can lead to vegetal elements has been identified as polysaccharide galactomannan, which is one of the excipient present in the drugs used. The authors have identified the origin of these contaminants and the means of pollution, using cytological and pharmaceutical investigation.