Semi-quantitative analysis of soft-tissue reactions in fine needle aspirates from tissue cysticercosis.

Fine needle aspiration cytology (FNA) has a well-documented role in the diagnosis of cysticercosis. However, little is discussed about the associated inflammatory response in the host tissues. Aspirates from 182 cases of subcutaneous cysticercosis were semiquantitated for the type and degree of inflammatory response, and the amount and preservation of the parasite. Tissue sections were reviewed where available. In the FNA where no parasite was observed but a confirmatory tissue diagnosis was available, it was found that eosinophils (52%), epithelioid cell granulomas (30%), palisading histiocytes (33%) and giant cells (28%) were seen less frequently than in those where larval fragments were identified in the aspirated material in varying quantities, the response being 88-92% eosinophils, 50-70% palisading histiocytes, 68-80% epithelioid cell granulomas and 46-74% giant cells. Repair cells were maximally seen when readily identifiable larval fragments were seen in the aspirate. Bizarre cells were equally distributed in these aspirates. The tissue response in FNA from subcutaneous cysticercosis can be varied and eosinophils are found to increase with the presence of the degenerating parasite. In soft-tissue aspirates, palisading histiocytes with epithelioid cell granulomas with or without giant cells and an inflammatory exudate with predominantly eosinophils alerts one to search diligently for a parasite.