A 36 year old man presented with a mass in the chest and multiple “hot” focal lesions were identified on bone scan. Fine needle aspiration was performed of the chest mass. Routine histology showed the presence of some bundles of dense fibrous tissue and a diffuse infiltration of mononuclear cells, which varied in size and nucleo-cytoplasmic ratio. The smaller cells had eccentric hyperchromatic nuclei. Nucleoli were noted in the larger cells. There was well marked cytoplasmic vacuolation of some of the cells. Mitosis was present. A small fragment of tissue was received for electron microscopy. Examination of 1 μm sections showed trabeculae of medium-large polygonal cells with eccentric nuclei and occasional nucleoli. Some irregularly shaped cells had well marked cytoplasmic vacuolation. Mitotic figures were present.
The Cytology of Benign, Pseudomalignant Reactive Changes in Fibrous Tissue, Adipose Tissue and Striated Muscle in Fine Needle Aspiration Samples
