SESSION TITLE: Infectious Disease Global Case Reports
SESSION TYPE: Global Case Report
PRESENTED ON: Tuesday, October 29, 2013 at 01:30 PM - 02:30 PM
INTRODUCTION: Mediastinal mass is one of the commonest radiological abnormalities observed in the practice of pulmonary medicine. Among all mediastinal masses located in various compartment 18-25% are cystic.(1) Thymic cysts, germ cell tumors (thymic carcinoid, teratomas, seminomas and non-seminomatous germ cell tumours), lymphangioma are examples of cystic mediastinal masses of anterior compartment.(1) Not all mediastinal masses are malignant or require surgery; some are benign and are amenable to medical treatment. Hence, it is important to apply rational and practical approach, recruiting as much clinical and radiological information as possible and find the underlying pathology for such lesions. Tuberculosis is a rare cause of mediastinal mass and need histopathology to confirm diagnosis.
CASE PRESENTATION: A 33-year-old male presented with complaints of left-sided chest pain for 5 months. He also had low-grade fever and dry cough. There was no hemoptysis or breathlessness. He received empirical antibiotics without relief in his symptoms. On examination, he was febrile and systemic examination was unremarkable. Investigations revealed a normal hemogram. The erythrocyte sedimentation rate was 40 mm during 1st hour. The results of clinical biochemistry including renal and hepatic functions were normal. ELISA for HIV was negative. Mantoux test done with 5 TU was positive (12 mm). Sputum for acid fast bacilli was negative on three occasions. Chest radiograph revealed a homogenous opacity at the left hilum. CECT scan of the chest revealed a cystic anterior mediastinal mass. There was no mediastinal or hilar adenopathy. The lung parenchyma was normal. The possibilities of thymic cyst or germ cell tumour were considered. Serum α-fetoprotein and β-human chorionic gonadotropin levels were normal. Fine needle aspiration cytology from the cystic mass under ultrasound guidance revealed epithelioid cell granulomas with necrosis and few multinucleate giant cells. With the diagnosis of tuberculosis patient was started with category I anti-tubercular drugs. He showed significant clinical and complete radiological resolution after completion of two months of therapy.
DISCUSSION: The common differential diagnoses of cystic anterior mediastinal mass are thymic cysts (entirely cystic), cystic thymoma (20%) or germ cell tumors (15%). These are typically asymptomatic and when symptomatic, it is usually due to pressure on surrounding structures. Hence the clinical presentation is of little help in making the diagnosis. Serum α-fetoprotein and β-human chorionic gonadotropin are helpful in excluding germ cell tumors. CT scan of the chest and mediastinum assist in determining the exact location of the mediastinal tumour and differentiates cystic lesions from those that are solid. The definite diagnosis requires needle aspiration or biopsy from the mass. In our case needle aspiration cytology clinched the diagnosis. Tuberculosis is a great mimic and can have myriad presentations but presenting as an isolated cystic mediastinal mass is rare.(2) A study on the cysts of the mediastinum for a period of twenty two years had revealed only two cases due to tuberculosis.(3) When it occurs, it is usually in associated with lung parenchymal lesion/s. Our case highlights the fact that tuberculosis should be considered as differential diagnosis of a cystic mediastinal mass even in the absence of parenchymal lesions especially in endemic zones.
CONCLUSIONS: In conclusion, tubercular infection can have varied presentations. With prompt commencement of ATT it is possible to treat these patients successfully with excellent prognosis.
Reference #1: Strollo DC, Rosado de Christenson ML, Jett JR. Primary mediastinal tumors. Part 1: tumors of the anterior mediastinum. Chest. 1997 Aug;112(2):511-22.
Reference #2: Khilnani GC, Jain N, Hadda V, Arava SK. Anterior mediastinal mass: a rare presentation of tuberculosis. J Trop Med.2011:635385.
Reference #3: Petkar M, Vaideeswar P, Deshpande JR. Surgical pathology of cystic lesions of the mediastinum. J Postgrad Med. 2001 Oct-Dec;47(4):235-9.
DISCLOSURE: The following authors have nothing to disclose: Neetu Jain, Gopi Khilnani, Vijay Hadda, Venkateswaran Iyer
No Product/Research Disclosure Information