A case of juvenile primary pulmonary malignant fibrous histiocytoma

An 18-year-old female presented with an abnormal shadow of a 22-mm nodule in the left anterior segment of the upper lung lobe (S3) on chest X-ray and computed tomography (CT). Thoracoscopic partial lobectomy was performed, when a frozen section suggested spindle cell sarcoma of extrapulmonary origin, including malignant fibrous histiocytoma (MFH). A histologic diagnosis of the MFH was rendered postoperatively on permanent sections. As no other primary focus was detected in spite of intensive investigation, including 18F-fluorodeoxyglucose positron emission tomography - CT scans, a definitive diagnosis was made of primary pulmonary MFH. Primary pulmonary MFH is usually treated by total resection, however, in the current case we performed a partial lobectomy with clear margins and a watchful follow-up without any additional aggressive treatment. No relapse has been observed for 3 years after the surgery.