Cystic fibrohistiocytic tumor of the lung presenting as a solitary lesion.

Cystic fibrohistiocytic tumor of the lung is a rare neoplasm. In many cases it represents a metastasis from a benign or low-grade fibrohistiocytic tumor of the skin, but occasionally it may be primary. Radiologically it usually occurs as a cystic change of multiple pulmonary nodules, and pneumothorax is the most frequent presenting symptom. We present here a 16-year-old man with recurrent right pneumothorax. The patient had no history of cutaneous fibrohistiocytic lesions. He underwent videothoracoscopic right apical segmentectomy, right lower lobe nodulectomy, and pleuroabrasion. Microscopy of the apical segmentectomy showed a cystic fibrohistiocytic tumor, whereas the nodule of the lower lobe was an intraparenchymal lymph node. The patient is alive with no tumor recurrence. The differential diagnosis includes Langerhans cell histiocytosis, lymphangioleiomyomatosis, pleuropulmonary blastoma, and metastatic endometrial stromal sarcoma. This disease usually occurs with multiple pulmonary cysts and cavitation. This case is the first reported presenting as a single lesion.