Osteosarcoma metastatic to adrenal gland diagnosed by fine-needle aspiration.

Osteosarcoma, a primary malignant tumor of the long bones, frequently metastasizes to the lungs. We report an unusual case of osteosarcoma metastatic to the right adrenal gland in a 37-yr-old male who presented 8 yr after remission with an adrenal mass. A preoperative diagnosis was made by fine-needle aspiration (FNA) biopsy. FNA biopsy revealed pleomorphic oval cells with prominent nucleoli, spindle cells, and giant tumor cells. Diagnostic osteoid was readily seen on smears and was also detected by polarization of cell-block section. Immunocytochemical stains revealed positivity of tumor cells for vimentin and osteonectin. Cytokeratin stains were negative. The cytologic diagnosis of metastatic Osteosarcoma was made, which was later confirmed upon resection of tumor by histology. Although the role of FNA in the diagnosis of primary bone tumors, including osteogenic sarcoma (OGS), remains controversial, this case, however, demonstrates the value of FNA biopsy combined with immunocytochemistry performed on the aspirated material in diagnosing osteosarcoma from an unusual location such as the adrenal gland.