Logistic regression analysis of high grade spindle cell neoplasms - A fineneedle aspiration cytologic study

OBJECTIVE: To identify primary diagnostic cytologic criteria for various hi gh grade spindle cell neoplasms. STUDY DESIGN: We reviewed 30 osteosarcomas, 29 malignant fibrous histiocyto mas (MFH), 26 malignant melanomas, 13 chondrosarcomas, 12 leiomyosarcomas, 7 angiosarcomas and 5 liposarcomas. All specimens were coded as to the pres ence or absence of the following variables: high or low cellularity, tissue like fragments, glandlike fragments, single cells, binucleated cells, multi nucleated cells, lipoblastlike cells, histiocytelike cells,Fibroblastlike c ells, signet-ring cells, short spindle cells, long filamentous cells, stell ate cells, osteoclastic giant cells, malignant giant cells, background cell s, pointed nuclei, cigar-shaped nuclei, fishhook-shaped nuclei, round or ov oid nuclei, intranuclear vacuoles, macronucleoli, small nucleoli, mitotic f igures, abnormal mitotic figures, pleomorphism, nuclear/cytoplasmic ratio ( mild, moderate, marked increase), amount of cytoplasm (scant, moderate, abu ndant), fine or coarse granular cytoplasm, intracytoplasmic hemosiderin dep osits, melanin, cytoplasmic vacuoles, fat, capillary vessel fragments, stor i-form pattern, necrosis, large or small amount of myxoid material, filamen tous stroma, dense collagenous stroma, osteoid, chondroid and cells in lacu nae. A logistic regression analysis was performed to identify the variables predictive of each diagnostic category. RESULTS: The statistical analysis selected positive expression of osteoid, osteoclastic giant cells and low cellularity as the primary criteria associ ated with osteosarcomas. Positive expression of fibroblastlike cells, large amount of myxoid material and multinucleated cells were identified to be t he key criteria for MFH. The analysis selected the presence of melanin as t he major criterion for malignant melanomas, cells lying in lacunae for chon drosarcomas, fishhook nuclei for leiomyosarcomas, intracytoplasmic iron dep osits for angiosarcomas and lipoblastlike cells for liposarcomas. CONCLUSION: From the previously described cytologic criteria, statistical a nalysis helped identify several key features that are significant in the ev aluation of pleomorphic spindle cell neoplasms.