Undifferentiated/unclassified sarcoma in the lung: A case report

Background. Primary pulmonary sarcomas are rare tumors, and their differential diagnosis has many branches. Case. A 79-year-old woman was urgently transferred to our institution complaining of hemoptysis. Chest computed tomography revealed a lung tumor measuring 5 cm in size in the central area of the right middle lobe. Bronchoscopy did not provide a definitive diagnosis. We performed right pneumonectomy for the diagnosis and treatment. A histological examination showed the proliferation of round to short spindle-shaped cells with oval nuclei. The tumor was unable to be classified into any well-defined categories due to the lack of distinguishing immunohistochemical features. Ultimately, a diagnosis of undifferentiated/unclassified sarcoma was made. Conclusion. Primary pulmonary sarcomas are very rare, and their differential diagnosis is sometimes difficult.