Successful retrieval of fine-needle aspiration biopsy material from previously stained smears for immunocytochemistry: a novel technique applied to three soft tissue tumors.

Fine-needle aspiration biopsies of soft tissue tumors are often not fully diagnostic on conventional Papanicolaou or Giemsa stains. Often, more useful information can be gleaned from preparing cell blocks, which are amenable to immunocytochemistry. However, sufficiently diagnostic cell block material is not always forthcoming. We subvent this problem by employing a new 'cytoscrape' technique to create cell blocks from previously Papanicolaou-stained smear material in two cases of mesenchymal tumors where smear diagnoses were limited to 'sarcoma, not otherwise specified'. After thorough text and photographic documentation of the smear results, the slides were decolorized and tumor cells were removed for processing as for routine preparation of cell blocks. Sections cut were then submitted for immunocytochemical profiling. This resulted in definitive diagnoses in both cases, averting the need for more invasive diagnostic procedures. We applied the same technique to a third case of a lung nodule, in which the smear was inconclusive and the original cell block nondiagnostic. The subsequent immunocytochemical testing enabled a definitive diagnosis to be made. This novel technique is described here; its value and applicability are discussed in the context of fine-needle aspiration biopsies of soft tissue tumors.