MICROINVASIVE FOLLICULAR THYROID-CARCINOMA DETECTED BY FINE-NEEDLE ASPIRATION SKELETAL METASTASES - A CASE-REPORT

BACKGROUND: Fine needle aspiration biopsy (FNAB) for the cytologic dia gnosis of bone metastatic lesions is often useful for locating the pri mary tumor and choosing treatment. The cytologic picture of follicular carcinoma most commonly resembles normal thyroid but may exhibit vari able anaplasia. Marginal vacuoles, also known as fire flare-like vacuo les and ''flame cells,'' have been found mainly in toxic goiter but al so in some nontoxic goiter. The presence of marginal vacuoles of FNAB of metastatic follicular carcinoma was first reported by Pitts et al i n 1988. CASE: A 77-year-old male presented with multiple lytic lesions involving the vertebral bones rand ribbons. FNAB of vertebral bone sh owed tumor cell clusters in a follicular pattern with peripherically s ituated, pink-stained vacuoles on May-Grunwald-Giemsa stain. CONCLUSIO N: FNAB is useful in the diagnosis of metastatic thyroid neoplasms. Th e recognition of marginal vacuoles, along with the appropriate cytolog ic findings, should provide morphologic cities leading to a suspicion of thyroid neoplasm metastasis in FNAB.