[423] Cytologic Evaluation of Primary Bone Lesions Sampled by Fine Needle Aspiration Biopsy: Diagnostic Utility

Valentina Robila, Gregory F Domson, William C Foster, Ema A Dragoescu. Virginia Commonwealth University, Richmond, VA

Background: Open biopsy is the traditional method for sampling bone lesions; however, this procedure puts the patients at risk for fracture and infection. A less traumatic approach is the image-guided needle biopsy technique, using either fine needle aspiration (FNA) or core needle biopsy (CNB) depending on the consistency of the lesion. These techniques yield less material and due to their rarity in clinical practice, pathologists have less experience interpreting these samples. This study analizes the diagnostic outcomes of FNA/CNB performed on bone lesions, with a special emphasis on primary bone tumors, in order to build evidence that a meaningful diagnosis can be rendered from these samples in most cases.
Design: All bone FNA/CNB (FNAB) performed with CT-guidance between 2006-2011 were reviewed. Site of involvement, method of collection, preliminary on-site interpretation, cytologic diagnosis, and follow-up were recorded.
Results: 220 bone FNABs were performed at our center during this interval. Biopsy sites were: pelvic bones (44.5%), long bones (23.1%), spine (20.4%), and other (12%). A useful interpretation was rendered in all but 2.7% nondiagnostic FNABs. 41 FNABs were from primary bone lesions: 73.1% CNB only, 24.4% CNB and FNA, and 2.5% FNA only. Touch imprints and smears provided useful diagnostic clues.

Table 1. Cytologic Findings in 41 Primary Bone Lesions FNABs

Cytologic interpretation (case numbers)	Findings on touch imprints/smear slides
Cartilage-forming tumors (13)	Chondroid matrix
Osteoid-forming tumors (2)	Rare osteoclasts and osteoblasts; no matrix
Ewing sarcoma (4)	Diagnostic material
Langerhans cell histiocytosis (LGH) (3)	Mixed inflammation, Langerhans cells present
Giant cell lesions (5)	Giant cells single or in groups
Fibro-osseous lesions (3)	Rare spindle cells
Sarcomas (3)	Diagnostic material
Glomus tumor (1), nerve sheath tumor (1)	Blood
Descriptive (6)	Blood or bone marrow elements

In conjunction with cell block, specific diagnoses were rendered in 35 cases (85.4%). On follow-up, the remaining 6 cases were: fibrous dysplasia, LCH, reactive histiocytic process, high-grade sarcoma, osteonecrosis; one case had no further evaluation. In 16 cases with surgical follow-up, histologic confirmation of the original cytologic diagnoses was made in all cases.
Conclusions: Our study indicates that a specific diagnosis can be rendered from FNAB samples in the majority of cases and supports the diagnostic utility and accuracy of this technique in sampling primary bone lesions.
Category: Cytopathology

Wednesday, March 21, 2012 1:00 PM

Poster Session VI # 82, Wednesday Afternoon