Fine-needle aspiration biopsy of the distal extremities: a study of 141 cases

We reviewed our cytopathology databases for an 11-year period to identify all fine-needle aspiration biopsy (FNAB) cases of palpable masses of the hand, wrist, ankle, or foot. Cases were included only if there was a subsequent tissue biopsy or a minimum 1-year clinical follow-up. Of 141 aspirates, 41, 23, 34, and 43 were from the hand, wrist, ankle, and foot, respectively. Specific benign or malignant diagnoses were achievable in 71.6% of cases, whereas the remaining cases were given a descriptive diagnosis (26.2%) or, infrequently, a "suspicious for" diagnosis (2.1%). Overall sensitivity and specificity for distinguishing a benign from malignant entity from all 4 sites were 100% and 96%, respectively, whereas positive and negative predictive values were 88% and 100%, respectively. The most common lesion was a ganglion. Of the benign neoplasms, giant cell tumor of tendon sheath (17) and desmoid-type fibromatosis (7) were most common. Of 31 malignancies, 24 were sarcomas: sarcoma not otherwise specified (6), high-grade pleomorphic sarcoma (5), and Ewing sarcoma (3) were most common. Seven nonsarcomas included melanoma (3), metastatic squamous carcinoma (2), and malignant lymphoma (2). An FNAB-procured cytopathologic diagnosis is clinically reliable in a high percentage of distal extremity mass lesions.