FINE-NEEDLE ASPIRATION BIOPSY OF GOUTY TOPHI - LESSONS IN COST-EFFECTIVE PATIENT-MANAGEMENT

Gout, a disease resulting from the effects of hyperuricemia and a crys tal-induced arthropathy, may produce soft tissue masses (tophi), which mimick neoplasia clinically and radiographically. We have recently di agnosed three cases of gouty tophus, two of which were clinically susp ected to represent sarcomas, by fine-needle aspiration biopsy (FNAB) a fter extensive radiologic and clinical evaluation There were two women and one man, aged 71, 73, and 50 yr, with palpable soft tissue masses that involved the right forearm, right hand, and right foot, respecti vely Biopsies were obtained by using 25-gauge needles without the aid of general anesthesia. Morphologically, aggregates and disassociated s lender, needle-shaped crystals were abundant and easily recognized on both Diff-Quik and Papanicolaou stains. By using a polarizing microsco pe with a first-order red compensator, the crystals showed negative bi refringence, characteristic of sodium urate, Benign-appearing histiocy tes, foreign-body-type giant cells, neutrophils, and amorphous debris were scattered among the diagnostic crystals. The diagnosis of gouty t ophus can be easily established with FNAB in conjunction with compensa ted polarizing microscopy. Application of FNAB in the initial evaluati on of appropriate soft-tissue masses provides a cost-effective diagnos tic method, preventing more costly and often unnecessary clinical and radiologic tests. (C) 1997 Wiley-Liss, Inc.