Fine needle aspiration cytology of chondroblastoma: A report of two cases with brief review of pitfalls.

Chondroblastoma is a rare, giant cell-rich, benign neoplasm of bone. Since the past few decades fine needle aspiration cytology (FNAC) has gained momentum in preoperative diagnosis of bone lesions. At cytology, other giant cell-rich tumors and tumorlike lesions such as aneurysmal bone cyst (ABC), giant cell tumor, and chondromyxoid fibroma fall under the differential diagnosis of chondroblastoma. Due to the difference in the treatment protocol and prognosis, preoperative diagnosis is mandatory. We describe the cytomorphology in two cases of chondroblastoma diagnosed at FNAC and confirmed by histopathology. At cytology, the presence of giant cells, chondroid matrix, mononuclear cells with nuclear indentation, and grooving along with glassy, vacuolated cytoplasm are characteristic of chondroblastoma. In addition to this, the presence of chicken wire calcification is a useful clue to the accurate diagnosis of chondroblastoma at FNAC.