An Inflammatory Pseudotumor Arising from the Mitral Valve

Shigeto Miyasaka	Keisuke Morimoto	Kengo Nishimura
Yoshikazu Fujiwara

（Department of Cardiovascular Surgery, Tottori Prefectural Central Hospital, Tottori, Japan, and Department of Cardiovascular Surgery, Tottori Kousei Hospital＊, Kurayoshi, Japan）

We herein report a rare case of an inflammatory pseudotumor arising from the mitral valve. A 58-year-old man who was undergoing maintenance dialysis was referred to us due to the presence of a tumor mass attached to the mitral valve. It was asymptomatic and had been coincidentally found by echocardiography. The tumor mass was a sphere measuring about 1 cm in size, and it arose from the posterior mitral leaflet. A myxoma of the left atrium was suspected, and the tumor mass was resected along with part of the posterior leaflet by means of a right minithoracotomy（MICS). The tumor was postoperatively diagnosed to be an inflammatory pseudotumor based on the findings of a histopathological examination. During the follow-up period of 1 year and 2 months after surgery, there was no recurrence. An inflammatory pseudotumor is a tumorous lesion characterized by the infiltration of inflammatory cells and the growth of myofibroblasts. This tumor occurs most frequently in the lung, and the greatest number of intracardiac cases have been reported in small children. There are few reports of inflammatory pseudotumors occurring in adults, and only 4 cases originating in the mitral valve has so far been reported, which means that such tumors are extremely rare. For this reason, we reported the findings of this case, while adding a bibliographical survey.　

Jpn. J. Cardiovasc. Surg. 44:184-187（2015）

Keywords：inflammatory pseudotumor;mitral valve;cardiac tumor