FINE-NEEDLE ASPIRATION BIOPSY OF SKELETAL VERSUS EXTRASKELETAL OSTEOSARCOMA

BACKGROUND. Although fine-needle aspiration biopsy (FNAB) of primary s keletal osteosarcoma (OS) has been described adequately, to the author s' knowledge, cytologic descriptions of extraskeletal OS appear limite d to only rare case reports. METHODS. In an attempt to analyze the uti lity and accuracy of FNAB in a diagnosis of skeletal versus extraskele tal OS, the authors retrospectively reviewed their 5-year experience. The study sample included 15 skeletal OS specimens (13 primary, 1 loca l recurrence, and 1 pulmonary metastasis) in 14 patients ages 10-58 ye ars (mean, 27 years; median, 25 years) and 5 extraskeletal OS specimen s (3 primary and 2 metastatic) in 4 patients ages 36, 37, 65, and 79 y ears, respectively. Based on accepted clinical criteria, two patients (a mother with extraskeletal OS and a daughter with skeletal OS) had L i-Fraumeni syndrome. RESULTS. Of the adequate primary skeletal OS case s analyzed by FNAB, 10 of 12 (83%) were diagnosed correctly and subseq uently treated according to a disease specific protocol. One case was considered unsatisfactory. One tumor initially was diagnosed as a gian t cell tumor and another was referred to nonspecifically as ''spindle- cell neoplasm.'' On histologic examination, the former case demonstrat ed a high grade fibroblastic OS arising within a giant cell tumor. Non e of the primary extraskeletal OS cases analyzed by FNAB was recognize d as OS. One was diagnosed nonspecifically as ''sarcoma'' and the othe r was referred to simply as ''atypical mesenchymal cells.'' A third ca se was comprised of scant fragments of adipose tissue, fibrous tissue, and cartilage and was considered unsatisfactory. Both examples of met astatic extraskeletal OS were recognized by FNAB. CONCLUSIONS. With ap propriate clinicoradiologic correlation, skeletal OS generally is easi ly diagnosed by FNAB. Because of the older age of most patients with e xtraskeletal OS and the rather nonspecific radiographic findings (e.g. , soft tissue mass), extraskeletal OS may not be recognized easily by FNAB and most likely requires incisional biopsy to establish a definit ive diagnosis in most cases. Additional larger series will be required before drawing definite conclusions. (C) 1998 American Cancer Society .