Which of the following is a variant of giant cell tumor (AIIMS Nov 2012)
|B||Non Ossifying fibroma|
Non Ossifying fibroma
a. Giant cell tumors represent 5% of bone neoplasms. They typically occur in patients 20 to 40 years old, and there is a slight female predominance.
b. The most common location for this tumor is the distal femur followed closely by the proximal tibia.
c. In the distal radius (the third most common location), these tumors frequently are more aggressive. Spinal involvement, other than the sacrum, is rare.
d. The lesions are eccentrically located in the epiphyses of long bones and usually about the subchondral bone.
Microscopically, giant cell tumors are composed of many multinucleated giant cells (typically 40 to 60 nuclei per cell) in a sea of mononuclear stromal cells. The nuclei of the mononuclear cells are identical to the nuclei of the giant cells, a feature that helps to distinguish giant cell tumors from other tumors that may contain many giant cells.
Treatment of choice is Extended curettage that is curettage with use of adjuvants, such as liquid nitrogen, phenol, bone cement, electrocautery, or an argon beam coagulator, theoretically help to kill any remaining tumor cells and decrease the chances of recurrence.
Other lesions that contain giant cells and are included in the list of giant cell variants is
a. Non ossifying fibroma
b. Fibrous dysplasia
c. Aneurysmal bone cyst
d. Unicameral (simple) bone cyst
f. Chondromyxoid fibroma
g. Brow tumor of hyperparathyroidism
In this list non ossifying fibroma, chondroblastoma and osteosarcoma features.
Osteosarcoma containing giant cells is rare and is the last preference and between chondroblastoma and non-Ossifying fibroma clinical, radiological and histopathological features non ossifying fibroma resembles giant cell tumor closely hence it is a preferable answer here.