: Aim: To address the paucity of published information on the cytology of the normal, term human placenta and to investigate syncytiotrophoblast nuclear organisation patterns using cytology techniques.
Materials and Methods: Following delivery, term placentas from normal pregnancies were sampled using fine needle aspiration (FNA) and direct scrapes. Air dried smears were stained with Giemsa; CytoLyt suspensions prepared as cytospins and ThinPrep slides were stained with Papanicolaou. Residual material was used to generate formalin fixed paraffin embedded cell blocks and cut as H&E sections. Standard histological examination was also performed for correlation and to exclude pathological changes.
Results: Fifty slides were generated for evaluation. Both Papanicolaou stained cytospin preparations and air dried Giemsa slides from FNA provided high quality material for assessment due to good cellularity and presence of villous “micro-biopsies” that allowed 3D appreciation of villus branching patterns. The nuclear chromatin pattern of both cyto and syncytiotrophoblast appeared finely clumped in all preparations and may represent pre-apoptotic change. Complex patterns of synctiotrophoblast nuclear organisation not previously described cytologically were observed including irregular spacing of nuclei, syncytioplasm windows and linear nuclear arrangements.
Conclusion: We have shown that placental FNA is feasible and a) provides technically excellent material for cytological evaluation b) confirms the presence of complex nuclear organisational patterns in the syncytiotrophoblast while eliminating the possibility of tangential sectioning artefact c) provides superior nuclear detail over standard histological sections and d) may be an untapped research resource because of its potential for in-vivo placental sampling.