A 28years old female presented with cough, dysponea and recurrent pulmonary infection. The CT and MRI Chest revealed middle mediastinal mass with pericardial attachment. She underwent midline sternotomy with successful enblock removal of the mass, the biopsy confirmed benign mature teratoma arising from pericardium. She was discharged on the 6 post operative day, and is in regular follow up.

Teratomata arise, in order of frequency, in the ovaries, testes, anterior mediastinum, retroperitoneal region, presacral and coccygeal regions, pineal and other intracranial sites, neck, and abdominal viscera other than the gonads (Willis, 1951). Mediastinal teratomata rank third among all teratoid tumours and are the second most common mediastinal tumours (Inada and Nakano, 1958). The majority...

The appearance of an anterior mediastinal mass during the follow-up of patients successfully treated for lymphoma is worrisome, and may suggest treatment failure. However, benign 'rebound' thymic hyperplasia (TH), a well documented phenomenon in children [1-3] and in young adults treated for malignant testicular teratoma [4], is an important differential diagnosis even in the adult population [5].

Somatic malignant transformation in mature cystic teratoma is a rare phenomenon of a malignancy of differentiated tissue structures of any stem line. The authors present a case of a 38-year-old female with mature cystic teratoma of both ovaries and with mucinous adenocarcinoma arising from endodermal germ line in the right ovary, showing immunohistochemical features of non-intestinal differenti...