We have previously shown that cytological diagnosis based on fine-needle as
piration biopsy (FNAB) is a safe and efficient method for the discriminatio
n between benign, primary malignant and metastatic bony lesions. We have no
w studied metastatic lesions to assess the diagnostic accuracy and to ascer
tain whether FNAB allows identification of the primary lesion.
Between 1990 and 1997, 447 patients were referred for diagnosis of skeletal
lesions of unknown type, Of these 119 proved to have metastatic disease, e
ither myeloma or lymphoma, Nine were excluded leaving 110 consecutive patie
nts with metastatic carcinoma (80), myeloma (16) or lymphoma (14),
FNAB gave a correct diagnosis in 102 of the 110 patients (93%), In eight it
was inconclusive, It correctly diagnosed 15 of 16 patients with myeloma, 1
2 of 14 with lymphoma, and 75 of 80 with metastatic carcinoma. Furthermore,
the site and type of malignancy were correctly suggested in two-thirds of
patients with metastatic carcinoma. Overall, only seven open biopsies were
carried out.
We conclude that time-consuming and costly investigations can be reduced by
choosing FNAB as the initial diagnostic method for skeletal lesions of unk
nown origin. The choice of radiological examinations, laboratory tests and
surgical biopsies can be determined by using FNAB.