INTRODUCTION: Mediastinal mature teratomas (MTT) in adults are uncommon typically asymptomatic tumors that arise in the anterior mediastinum. Usually, they are benign and resectable. Seldomly, they rupture into adjacent cardiothoracic structures. Hemoptysis as a presenting symptom is rare. Among adults, bacterial infection complicating MMT rupture has not been described. We report a man who presented with hemoptysis and infected MMT.
CASE PRESENTATION: A 58 year old man from Ghana was hospitalized following five days of hemoptysis, cough, dyspnea, and pleuritic left chest pain. Twelve years earlier he was treated for pneumonia. The left upper hemithorax revealed reduced tactile fremitus, dullness, and monophonic rhonchi. Routine laboratory tests were normal. A tuberculin skin test was non-reactive. Sputum smears and cultures revealed no tuberculosis. Blood cultures were without growth. A chest radiograph revealed a large opacity with multiloculated lucencies superior and adjacent to the left heart border. Non-contrast computerized tomography (CT) of the chest showed a 6.2 cm X 7.0 cm X 4.0 cm necrotic cavitating heterogeneous anterior mediastinal mass containing fat, soft tissue, and gas that suggested bronchial rupture. The mass appeared to occlude the anterior segmental bronchus of the left upper lobe, invade the left hilum posteriorly, and extend directly into pericardium. Figure 1. Non-contrast chest CT showing the mediastinal mass extending into pericardium. Fiberoptic bronchoscopy revealed left upper lobe bronchial edema and, at its origin, left lower lobe narrowing by external compression. All segmental and subsegmental bronchi were patent and without lesions. Transthoracic needle biopsies of the mass demonstrated thymic tissue, respiratory epithelium, and both apocrine and eccrine sweat glands, consistent with mature cystic teratoma. No malignant cells were identified. MMT tissue grew Hemophilus influenza. Figure 2. Photomicrographs showing respiratory epithelium (Left) and apocrine and eccrine sweat glands (Right) in the MMT biopsies (10X). During median sternotomy, tumor was seen infiltrating through ruptured pericardium and around both ventricles. The left anterior descending coronary artery coarsed through the mass. Complete dissection of the tumor from the heart was impossible. Hemoptysis, chest pain, and dyspnea sub-sided during treatment with pipercillin-tazobactam. Repeat chest CT six months later showed no significant interval change. Nine months post-operatively he felt well without symptoms.
DISCUSSIONS: Our patient with MMT is unique because (a) he presented with hemoptysis (rare) and (b) he had bacterial infection of the MMT (not described before in adults). Hemoptysis and chest CT evidence of gas in the MMT reflected tumor and tracheobronchial tree rupture. Mechanisms for rupture include MMT infection and release of proteolytic enzymes from pancreatic/intestinal mucosal tissues contained in the MMT. We found no evidence of infection beyond the MMT itself to explain its rupture; e.g., pneumonia, and therefore, we speculate that rupture resulted from MMT proteolytic enzyme release and led to hemoptysis and MMT infection. Pancreatic tissue, the most common one found in MMT, was not found in our small needle biopsy specimen, but the unsampled tumor likely contained pancreatic/intestinal mucosal tissue. Even though the MMT in our patient was benign and histologically mature, complete resection, the treatment of choice, was impossible because the MMT had infiltrated pericardium and encased both ventricles and the coronary arteries. Tumor resection under cardiopulmonary bypass, reconstruction of the loculated ventricles, and heart-lung transplant are future treatment considerations.
CONCLUSION: We report a mediastinal mature teratoma with a combination of rare features not previously described: the presentation of a MMT with hemoptysis, Hemophilus influenza infection in an adult, bronchial and intrapericardial rupture, and unresectable nature of a benign tumor.
DISCLOSURE: Karthik Jothianandan, No Financial Disclosure Information; No Product/Research Disclosure Information