https://imcjms.com Ibrahim Medical College Journal of Medical Science https://imcjms.com/registration/journal_full_text/223 Thu, 18 May 2017 10:11:44 +0000 Mediastinal lipoma (ML) is a rare entity. Though the mediastinum is the most common site of intrathoracic lipoma, ML constitutes less than 1% of all mediastinal tumours. ML frequently presents on incidental radiographic finding, CT scan is considered the investigation of choice. CT features of lipoma are quite characteristic. They are clinically significant because: (1) Despite their benign nature, these tumours tend to reach an enormous size and can cause compression of lungs and mediastinal structures; (2) It may not always be possible to differentiate a ML from a liposarcoma by CT or MRI alone. Address for Correspondence:Dr. Jafreen Sultana Assistant Professor, Department of Radiology & Imaging, Ibrahim Medical College & BIRDEM Hospital, 122 Kazi Nazrul Islam Avenue, Shahbagh, Dhaka, Bangladesh   Most mediastinal lipoma are discovered incidentally. Although lipoma are the most common benign neoplasm, its occurrence within the thoracic cage is uncommon. In contrast to the frequently multiple subcutaneous lipoma, intrathoracic lipoma is usually a single lesion. Multiple intrathoracic lipomas have been reported rarely.1 Case Report On admission chest radiograph and CT scan were done. Chest X-ray P/A view showed a lobulated opacity in the left mid and lower zones near paracardiac location obscuring the left cardiac border and left hemidiaphragm. Ill-defined opacity was also seen in the right lower zone (Fig. 1a).       Fig 1b. Contrast enhanced CT scan of chest shows the non-enhancing fat density lesion in the anterior mediastinum. Her past history revealed that in the year 2002, the patient had a thoracotomy for anterior mediastinal mass. The patient was admitted with the same complain and a chest X-ray (Fig. 2a) and subsequent CT scan (Fig. 2b) revealed a large lesion mostly in right hemithorax and partly on the left side with evidence of compression on superior vana cava and pulmonary arteries with their posterior displacement. Significant lung compression was also present at that time. The patient underwent right sided thoracotomy on February 2002. The encapsulated mass was completely excised including the capsule. Histopathology revealed lipoma and no evidence of malignancy. Post operative recovery was uneventful with satisfactory lung expansion. The patient was alright for the last few years but again developed the same complaints of dyspnoea (2009) and was admitted in the hospital once again. As mentioned ealier, X-ray and CT scan revealed a lipomatous lesion which was subsequently cinfirmed by CT guided FNAC. The final radiological diagnosis was recurrence of mediastinal lipoma.     Fig 2b. CT scan of chest shows a large, non-enhancing hypodense mass in the anterior mediastinum.   Lipomas are well circumscribed mesenchymal tumors that originate from adipose tissue.2 They occur predominantly in the anterior mediastinum and are reported to represent 1.6-2.3% of all primary mediastinal tumours.3,4 Because of the slow growth of the lesions, the presenting symptoms are often due to mass effect (i.e., compression of primary bronchi, esophagus, phrenic nerve, or vagus nerve). Symptoms can include dysphagia, dyspnea, dry cough, jugular distension, and cardiac arrhythmias.2 Simple excision of this well-demarcated tumor can be performed if it is symptomatic. In its undifferentiated form, a liposarcoma may be identifiable from a lipoma due to the higher density and better enhancement. But this differentiation is lost in a well-differentiated and encapsulated liposarcoma.5 For this reason a complete excision is the diagnostic and therapeutic modality of choice. Where surgery is not contemplated as in small and asymptomatic lesion, a needle biopsy or a thoracoscopic incisional biopsy is necessary. When the report is a liposarcoma, an excision is essential. A biopsy picture of a lipoma in such a patient may be managed by clinical and chest CT follow up. When attempted, surgical removal of lipoma must be completed due to a tendency of recurrence. Conclusion   1.   Johansson L, Soderlund S. Intrathoracic lipoma. Acta chir Scand 1963; 126: 558-565. 3.   Baris YI, Kalyoncu AF, Aydiner A, Gulekon N, Eryilmaz M, Selcuk ZT, Sahin AA. Intrathoracic lipomas demonstrated by Computed Tomography. Respiration 1990; 57: 77-80. 5.   Tanaka F, Kitano M, Tatsumi A, Huang CL, Nagasawa M. A case of mediastinal liposarcoma. Nippon Kyobu Geka Gakkai Zasshi. J Jpn Thoracic Surg Soc 1992; 40: 1125-1130. 2026 Ibrahim Medical College. All rights reserved.