Diagnosis of primary fibrosarcoma of the lung by fine-needle aspiration and core biopsy - A case report and review of the literature

Primary pulmonary sarcomas are uncommon neoplasms. Primary fibrosarcoma of the lung is extremely rare, and only 53 cases have been documented in the l iterature to date. To our knowledge, the diagnosis of primary lung fibrosar coma by fine-needle aspiration cytology has never been reported. We report a case of pulmonary fibrosarcoma diagnosed by fine-needle aspiration cytolo gy and core biopsy. The neoplasm consisted of interweaving fascicles of min imally atypical spindle cells with slender nuclei and scant cytoplasm. Posi tive immunohistochemistry for vimentin along with nonreactivity of tumor ce lls for keratin, S100 protein, desmin, or-smooth muscle actin, and CD34 sup ported the the diagnosis. The diagnosis was later confirmed by histologic a nd ultrastructural findings following lobectomy. A meticulous clinical sear ch for a possible primary neoplasm elsewhere was unsuccessful, and lung was established as the primary site. Fine-needle aspiration cytology and core biopsy are reliable methods for establishing a diagnosis of fibrosarcoma.