A new filter technique permitting traditional histopathological assessment of fine needle aspiration specimens.

We describe a new filtration method based on a transport medium technique which allows histopathological assessment of the tissue fragments present in many fine needle aspirates. Fine needle aspiration cytology and biopsy preparations obtained from equally divided transport medium specimens were compared in a study comprising 104 palpable breast lesions and 29 other miscellaneous lesions. In general, fine needle aspiration biopsy provided better information on tumour origin and differentiation than fine needle aspiration cytology, particularly with systemic aspirates and those which were heavily bloodstained. In most instances fine needle aspiration biopsy also provided sufficient material to perform specialised staining and immunohistological techniques, and it is suggested that it may have a role in supplementing direct smear fine needle aspiration cytology in these areas.