A Misdiagnosis of a Huge Lung Fibroleiomyomatous Hamartoma in Pleural Cavity

Abstract

Backgroud: Lung fibroleiomyomatous hamartoma is an extremely rare benign tumor in lung, it belongs to hamartoma. There were only five patients with solitary pulmonary fibroleiomyomatous hamartoma reported in literatures and our case has the largest size of the tumor from lung.Case presentation: Our case is a 36-year woman with a huge mass in pleural cavity. She was once misdiagnosed mediastinal germ cell tumor with pleural effusion through percutaneous lung biopsy in other hospital. After traditional thoracotomy, a huge size of 22 x 18 x 5.5 cm mass was completely dissected and a diagnosis of pulmonary fibroleiomyomatous hamartoma was given by pathology combined with immunohistochemical staining, which showed the positive staining of SMA, Desmin, CD34, BCL2, TTF1, Napsin A, and CK7, and the negative staining of S-100 and Calretinin. The patient recovered well with 40 months following up without recurrence.Conclusions:In our case, we had reported the largest size of lung fibroleiomyomatous hamartoma. The treatment of fibroleiomyomatous hamartoma is completely resected it and have a good prognosis.