Most common posterior mediastinal tumor is:

Ans: A (Neruofibroma) Ref: Bobbins Pathologic basis of Disease, 8th ed.Explanation:Mediastinal TumorsAnterior (front) mediastinumGerm cell Tumors - The majority of germ cell neoplasms (60 to 70%) are benign and are found in both males and females.Lymphoma - Malignant tumors that include both Hodgkin's disease and non Hodgkin's lymphoma.Thymoma and thymic cyst - The most common cause of a thymic mass, the majority of thymomas are benign lesions that are contained within a fibrous capsule. However, about 30% of these may be more aggressive and become invasive through the fibrous capsule.Mediastinal Thyroid mass - Usually a benign growth, such as a goiter, these can occasionally be cancerous.Middle mediastinumBronchogenic cyst - A benign growth with respiratory origins.Mediastinal Lymphadenopathy - An enlargement of the lymph nodes.Pericardial cyst - A benign growth that results from an ''out-pouching" of the pericardium (the heart's lining).Mediastinal Thyroid mass - Usually a benign growth, such as a goiter. These types of tumors can occasionally be cancerous.Tracheal tumors - These include tracheal neoplasms and non-euplastic masses, such as tracheobronchopathia osteochondroplastica (benign tumors).Vascular abnormalities including aortic aneurysm and aortic dissection.Posterior (back) mediastinumExtramedullary haematopoiesis - A rare cause of masses that form from bone marrow expansion and are associated with severe anemia.Mediastinal Lymphadenopathy- An enlargement of the lymph nodes.Mediastinal Neuroenteric cyst- A rare growth, which involves both neural and gastrointestinal elements.Mediastinal Neurogenic neoplasm- The most common cause of posterior mediastinal tumors, these are classified as nerve sheath neoplasms, ganglion cell neoplasms, and paraganglionic cell neoplasms. Approximately 70%. of neurogenic neoplasms are benign.Oesophageal abnormalities including achalasia oesophageal, oesophageal neoplasm and hiatal hernia.Paravertebral abnormalities including infectious, malignant and traumatic abnormalities of the thoracic spine.Mediastinal Thyroid mass- Usually a benign growth, such as a goiter, which can occasionally be cancerous. Vascular abnormalities - Includes aortic aneurysms.