OBJECTIVETo summarize the diagnostic features of fine needle aspiration cytology (FNAC) of myxoid lesions in soft tissue, and to define the cytological criteria for differentiating benign lesions from sarcomas and between various myxoid lesions.

METHODSFNAC data of 24 soft tissue myxoid lesions (14 benign lesions, 10 malignant lesions) from 1993 to 2006 from Kiang Wu Hospital, Macau were reviewed in correlation with the clinical course or the results of biopsy.

RESULTSGanglion, myxoma, and myxoid nodular fasciitis were the most common benign myxoid lesions of the soft tissues, all of which had low cellularity and lack of marked cellular atypia in smears in common. Ganglion was characterized by the disappearance of or the gradual minimization of the nodule after aspiration and the lack of blood vessel in smears. Myxoid nodular fasciitis was characterized by a pleomorphic pattern of proliferative cells and the presence of ganglion cell-like cells. Myxoid liposarcoma, extraskeletal myxoid chondrosarcoma and myxofibrosarcoma were the most common myxoid sarcomas. Cytologically, they had high cellularity and various degrees of cellular atypia. Myxoid liposarcoma exhibited branching chicken-wire like capillary vessels and/or lipoblasts; myxofibrosarcoma were prominent in both pleomorphic and atypia of the cells. The data revealed that the diagnostic accuracy of FNAC was nearly 100% in differentiating benign and malignant myxoid lesions of the soft tissues. The coordinate rate to the histopathology diagnosis of the common myxoid lesions of the soft tissues was above 75% (benign 71.4% and malignancy 80% respectively).

CONCLUSIONSFNAC is an effective method in diagnosing myxoid lesions of soft tissue, in correlation with the clinical data and the accessory examinations. FNAC can provide an objective basis for the treatment of myxoid lesions and prevention of unnecessary surgical operations.