Fine-needle aspiration biopsy features in a case of giant cell fibroblastoma of the chest wall.

Giant cell fibroblastoma is an unusual tumor of childhood, primarily occurring in the superficial soft tissues. We describe the fine-needle aspiration biopsy features of a case of giant cell fibroblastoma of the chest wall in a 3-year-old child. The aspirates comprised bland spindle to oval cells entrapped in a metachromatic matrix, accompanied by rare multinucleated giant cells with wreathlike nuclei. Although we were unable to render a definitive diagnosis on fine-needle aspiration biopsy, surgical resection of the mass established the diagnosis of giant cell fibroblastoma. We review the distinctive cytologic features of some common soft tissue tumors arising in this age group that may give rise to a diagnostic conundrum on fine-needle aspiration biopsy.