CHONDROBLASTOMA OF BONE - USE OF FINE-NEEDLE ASPIRATION BIOPSY AND POTENTIAL DIAGNOSTIC PITFALLS

Chondroblastoma of bone is a well-characterized entity When the radiog raphic features are classic and the lesion is present in typical locat ions (i.e., epiphysis of a long bone), the diagnosis is often easily e stablished by fine-needle aspiration biopsy and/or surgical curettage. Tumors in unusual locations, in older patients, or when complicated b y aneurysmal bone cysts may pose more diagnostic difficulty. We report four examples (three primary and one recurrent) of chondroblastoma of bone diagnosed by fine-needle aspiration biopsy. All patients were me n, ranging from 18 to 28 yr of age, age. Sites of involvement included the acromion process of the scapula, left humerus, right ischium, and left distal femur. Three of the tumors were diagnosed as chondroblast oma on fine-needle aspiration cytology; the fourth case, involving the scapula, consisted mostly of a large aneurysmal bone cyst and remaine d unrecognized until surgical curettage was performed. Typical-appeari ng chondroblasts were present in three of the cases; osteoclast-type g iant cells were observed in all four cases. Matrix material consistent with chondroid was also identified in all cases. We believe that in t he absence of inflammatory cells, the presence of classic-appearing ch ondroblasts, even without chondroid matrix, is sufficient for diagnosi s of chondroblastoma of bone. Diagn. Cytopathol. 16: 65-71, 1997. (C) 1997 Wiley-Liss, Inc.