Large Mature Teratoma Presenting as Incidental Mediastinal Mass on Chest Radiograph

SESSION TITLE: Student/Resident Case Report Poster - Lung Pathology I SESSION TYPE: Student/Resident Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: Only 1-5% of all germ cell tumors (GCTs) are extra-gonadal. The mediastinum is the most common location for these tumors, and mature teratoma is the most common morphology of medistinal GCTs. CASE PRESENTATION: We present the case of an asymptomatic 26 year old female with a history of urticaria an allergic rhinitis who presented to her PCP for evaluation of a left hemithorax opacity incidentally diagnosed on CXR obtained during her green card application. Chest CT confirmed the presence of a loculated cystic left chest mass measuring 14 x 9 x 15 cm. The patient was initially referred to pulmonology, then to thoracic surgery after CT-guided aspiration that revealed benign histiocytes and lymphocytes. The patient underwent uncomplicated video-assisted thoracoscopy with resection of a multiloculated cystic structure filled with straw-colored serous fluid and yellow-gray grumous material without solid components that appeared to originate from the left lobe of the thymus. Pathology revealed a benign mature teratoma without neural elements. DISCUSSION: Mediastinal mature teratomas are rare, frequently asymptomatic, and discovered only incidentally as a result of their slow growth and the compliance of adjacent lung tissue. They may present with chest pain, dyspnea, cough, or less commonly hemoptysis or other complication of rupture. Historically trichoptysis has been described. Benign teratomas are most commonly cystic, whereas malignant teratomas are more commonly solid. Differential diagnosis includes malignant (immature) teratoma, and parasitic, fungal, or bacterial collections. After metastasis from a gonadal primary has been excluded, surgical excision is usually curative. CONCLUSIONS: The present case is a common presentation of a rare condition that highlights the importance of accurate diagnosis and expedient excision. Reference #1: Dasbaksi, Kallol, et al. “Intrapulmonary teratoma: Report of a case and review of literature.” Asian Cardiovascular and Thoracic Annals (2015): 0218492315583763. Reference #2: Drevelegas, Antonios, Panagiotis Palladas, and Anna Scordalaki. “Mediastinal germ cell tumors: a radiologic-pathologic review.” European radiology 11.10 (2001): 1925-1932. Reference #3: McKenney, Jesse K., Amy Heerema-McKenney, and Robert V. Rouse. “Extragonadal germ cell tumors: a review with emphasis on pathologic features, clinical prognostic variables, and differential diagnostic considerations.” Advances in anatomic pathology 14.2 (2007): 69-92. DISCLOSURE: The following authors have nothing to disclose: Sam Tirgari, Abraham Markin, Lester Kobylak No Product/Research Disclosure Information