Leiomyosarcoma of the soft tissue. A correlative cytological and histological study of 11 cases.

Leiomyosarcoma of the soft tissues is a well-defined and characteristic entity histologically but correlative cytomorphological studies are lacking. A correlative histological and cytological study of 11 cases is presented. The leiomyosarcomas were characterized histologically by elongated tumour cells arranged in bundles intersecting each other at wide angles. The nuclei were elongated and often blunt-ended, tending to be aligned in tandem-position or in rows. The smears from leiomyosarcoma were poor in tumour cells and most cells were arranged in clusters of strands. The characteristic blunt-ended cells and nuclei of leiomyosarcoma could be identified in the smears and the nuclei were focally arranged in rows and sometimes in parallel. Nuclear atypia permits diagnosis of malignancy, although the atypia was generally not very pronounced. We consider that a knowledge of the corresponding histological features is mandatory for differentiating cytologically between various soft tissue sarcomas, including leiomyosarcomas. Further correlative cytological and histological studies of other soft tissue sarcomas are necessary for a more valid interpretation of the smears from leiomyosarcomas.