A Rare Case With Pulmonary and Cardiac Inflammatory Myofibroblastic Tumor
A 9-year-old girl was admitted to the hospital because of exertional dyspnea, intermittent fever and fatigue, and inappetence for 3 months. She did not have chills or night sweats and had not lost weight.
She was in mild respiratory distress with a respiratory rate of 34 breaths/min and a heart rate of 100 bpm that was regular in rhythm. Her blood pressure was 94/62 mm Hg. Cardiac auscultation revealed a distinct early diastolic click followed by a grade 2/5 diastolic decrescendo murmur at the apex that was variable in character with postural changes. Chest x-ray, posterior-anterior view, showed that the cardiothoracic ratio was increased. A high density was noted behind heart. The left lateral view showed an enlarged left atrium and abnormally high density at the region of lower left pulmonary hilar (Figure 1).
The ECG showed sinus rhythm, left atrium enlargement demonstrated by bifid P wave with >40 milliseconds between the 2 peaks and a total P-wave duration of >110 milliseconds in lead II. A biphasic P wave was seen with a terminal negative portion that was >40 milliseconds in duration and >1 mm deep in V1 (Figure 2).
Transthoracic echocardiography revealed a large mass with a clear boundary in the left atrial chamber. It protruded into the left ventricular cavity through the mitral annulus during diastole, obstructing mitral inflow. There was small amount of cardiac effusion (Figure 3A and Movie I in the online-only Data Supplement). An atypical 4-chamber view showed a mass in the left atrium that was connected to the mass in the dilated left lower pulmonary vein (Figure 3B and Movie II in the online-only Data Supplement).
The 4-chamber view of the magnetic resonance image showed that the mass was smooth and lobulated, with 1 part located in the left atrium and connected to another part in the left lung via the left lower pulmonary vein (Figure 3C and Movie III in the online-only Data Supplement). The precontrast T1-weighted imaging showed that the tumor was substantially uniform and significantly enhanced by early and late contrast infusion.
According to its size associated with invasion of the heart and pulmonary vein, the primary diagnosis was cardiac malignant tumor. Thus, we recommended complete resection for diagnosis and treatment. The differential diagnosis included a variety of neoplastic and reactive lesions ranging from fibrohistiocytic neoplasms, lymphoma, primary lung and cancer or sarcoma to fibrosis. Investigation of our case with echocardiography and magnetic resonance imaging showed a left atrial mass with a clear boundary that protruded into the left ventricular cavity, obstructing mitral inflow, and the mass was connected to the left lower pulmonary vein.
The pathology gross examination revealed tumor of the left lung lower lobe and left atrium that was dumbbell shaped with a smooth surface. There was a clear boundary but no capsule. The larger part of the tumor with a size of 3.5×2.5 cm was in the left atrium; the smaller part with a size of 1.0×1.0×0.5 cm was in the lung. The tumor sections were homogeneously solid, grayish white, and hard (Figure 4, left and middle). Histological examination revealed that the tumor consisted of spindle-shaped cells and myxoid stroma with infiltration of lymphocytes, plasma cells, and monocyte inflammatory cells (Figure 4, right).
After the operation, patient recovered uneventfully. She was in good condition, and echocardiographic examination at the 1-year follow-up was normal.
Inflammatory myofibroblastic tumor (IMT) of the heart is rare, with <60 cases reported in the literature using various terminologies, including IMT, plasma cell granuloma, inflammatory pseudotumor, and inflammatory fibrosarcoma.1 Although the majority of cardiac tumors follow a benign course after surgical resection, sudden death resulting from cardiac IMT has been reported in 5 cases, including 2 cases as a result of tumor occluding the coronary artery.2,3 Because cardiac IMT may potentially be fatal if a cardiac valve or the coronary arteries are involved, whenever feasible, complete surgical resection of the tumor remains the mainstay of treatment and seems to have a satisfactory outcome. However, the possibility of recurrence and the long-term prognosis after cardiac surgery have not been determined because of the rarity of these lesions. Recurrence of IMT in heart is rare. Hartyánszky and colleagues4 described a patient with recurrent IMT in the right ventricular outflow tract. We report a very rare case of a patient with exertional dyspnea caused by obstruction of the mitral inflow by a large IMT in the left atrium. The echocardiographic image indicated that the tumor extended to the lung via its connection at the dilated left lower pulmonary vein, which was confirmed by cardiac magnetic resonance imaging. In fact, the operative finding indicated that the tumor originated from the pulmonary vein that extended into the left atrium. The diagnosis of IMT was confirmed by histopathology. The tumor was successfully removed by surgery, and the patient was in good condition at the 1-year follow up.
Our case indicates that the cardiac imaging is very useful for the diagnosis of cardiac tumors. Echocardiography is readily available and relatively inexpensive, and cardiac magnetic resonance imaging or computed tomography can be used as complementary imaging. To the best of our knowledge, this is the first case of a cardiac IMT connected to another part of the tumor in the left lower lung.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/lookup/suppl/doi:10.1161/CIRCULATIONAHA.115.014306/-/DC1.
- © 2015 American Heart Association, Inc.