Cytodiagnosis of a meningeal fibrosarcoma metastatic to the thyroid gland

A case of primary leptomeningeal fibrosarcoma metastatic to the thyroid gland, diagnosed by fine needle aspiration biopsy is described. The patient, a 39-year-old women was initially diagnosed with a leptomeningeal fibrosarcoma. Sections of the primary tumor studied by electron microscopy showed that the tumor cells have the ultrastructure features of a fibroblast. She underwent tumor resection, followed by chemotherapy and local radiotherapy. Four months later, she presented with dysphagia. Ultrasonography confirmed the presence of a 2-cm mass in the right lobe of thyroid. A fine needle aspiration biopsy was performed. Light microscopy showed interwoven bundles of neoplastic spindle cells similar to the primary tumor, consistent with a metastatic fibrosarcoma. To our knowledge, this is the first report of a primary meningeal fibrosarcoma that metastasized to the thyroid gland, which was diagnosed by a fine needle aspiration biopsy.