Mediastinal lipomatosis: as a rare complication of systemic steroids in an adolescent with lupus nephritis

Abstract

To the Editor Mediastinal lipomatosis ML is a rare condition caused by excessive fat accumulation in the mediastinum 1 It is frequently related to endogeneous or iatrogenic Cushing syndrome or obesity 2 3 Patients with mediastinal lipomatosis may be asymptomatic or may present with clinical findings which are caused by excessive fat accumulation and may lead to severe compression findings The most common radiologic finding is bilateral enlargement in the mediastinum on postero anterior chest graphy and can be confused with mediastinal masses 1 The definite diagnosis is made by computarized tomography CT or magnetic resonance imaging MR 4 5 Steroid related ML generally has a good prognosis and improves when the dose of steroid is decreased or steroid treatment is discontinued However patients with severe compression findings who need surgical intervention have been reported in the literature 5 6 We wanted to draw attantion to a rare complication of systemic steroid use with this case A 17 year old female patient who was diagnosed as systemic lupus erytemathosus SLE and whose renal biopsy was compatible with stage IV diffuse membranoproliferative glomerulonephritis had received multiple intravenous high dose methylprednisolone intravenous cyclophosphamide and oral prednisolone and azathioprine mycophenalate mofetil MMF treatments because of active disease When she presented for follow up visit she was using 40 mg prednisolone and 1000 mg MMF On physical examination she appeared fallen and pale Moon face bufallo hump and pretibial edema were present Her blood pressure was found to be 150 100 mmHg her pulse rate was found to be 86 min and her respiratory rate was found to be 20 min She had no peripheral lympadenopathy or organomegaly A 2 6 systolic murmur was heard at the mesocardiac area Other system examinations were found to be normal Laboratory tests revealed a deep anemia hemoglobin: 6 5 g dL haptoglobin: lt;28 5 mg dL hyoalbuminemia serum albumin: 2 6 g dL proteinuria urinary protein: 2 1 g day and renal dysfunction serum creatinine: 2 2 mg dL On antero posterior chest graphy bilateral mediastinal enlargement was observed Figure 1 Echocardiography revealed pericardial effusion 6 mm and hypertension secondary to left ventricular hypertrophy findings Thoracic CT without contrast was performed with a suspicion of mediastinal mass and widespread fat accumulation was found Figure 2 No mediastinal adenomegaly or mass was observed Sterioid related ML was considered in the patient who had a history of long term use of high dose steroid and the dose of steroid was reduced up to 10 mg but steroid treatment could not be discontinued since the disease had an active course On the follow up graphy taken 4 weeks later enlargment in the mediastinum was observed to be regressed Mediastinal lipomatosis is a rare complication of systemic steroids and was described by Koerner and Sun 1 in 1966 for the first time As far as we know steroid ndash;related ML has been reported only in one pediatric subject until the present time 7 While some patients have no clinical findings some others may have severe compression findings related to airways vena cava superior heart and other organs 6 8 9 10 Our patient had no clinical finding suggesting compression of ML However ehcocardiography of our patient revealed pericaridal effusion When the cases in the literature were evaluated it was found that Hsu et al 11 reported a case of pericardial effusion related to ML However we think pericardial effusion can not be explained with ML alone in our patient who was being followed up with a diagnosis of SLE and who had hypoalbuminemia The diagnosis of mediastinal lipomatosis is generally made by observation of mediastinal enlargement on chest graphy and demonstration of intensity changes related to fat on CT or MR imaging In our patient mediastinal enlargement was observed initially and CT was performed considering secondary malignancy because of a history of long term and intensive immunosupressive treatment A diagnosis of ML was made by demonstrating widespread fat mass on CT ML was thought to be related to steroid in our patient who was known to have used long term steroid and who had clinical findings related to steroid use moon face and bufallo hump Regression of mediastinal enlargement with reduction of steroid dose supported the diagnosis Conclusively ML is a rare complication which should be considered in the differential dignosis in patients who hava a history of systemic steroid usage and mediastinal enlargement Nur Canpolat1 Sebuh Kuruğoğlu2 Lale Sever1 Salim Çalışkan1 Meltem Kıvılcım3 Özgür Kasapçopur4 Nil Arısoy4 1İstanbul University Cerrahpaşa Medical Faculty Division of Pediatric Nephrology İstanbul Turkey 2İstanbul University Cerrahpaşa Medical Faculty Department of Radiology İstanbul Turkey 3İstanbul University Cerrahpaşa Medical Faculty Department of Pediatrics İstanbul Turkey 4İstanbul University Cerrahpaşa Medical Faculty Division of Pediatric Rheumatology İstanbul Turkey References 1 Koerner HJ Sun DI Mediastinal lipomatosis secondary to steroid therapy Am J Roentgenol Radium Ther Nucl Med 1966; 98: 461 464 2 Nguyen KQ Hoeffel C Le LH Phan HT Mediastinal lipomatosis South Med J 1998; 91: 1169 1172 3 Lee WJ Fattal G Mediastinal lipomatosis in simple obesity Chest 1976; 70: 308 309 4 Enzi G Biondetti PR Fiore D Mazzoleni F Computed tomography of deep fat masses in multiple symmetrical lipomatosis Radiology 1982; 144: 121 124 5 Nguyen KQ Hoeffel C Le LH Phan HT Mediastinal lipomatosis South Med J 1998; 91: 1169 1172 6 Taille C Fartoukh M Houel R Kobeiter H Remy P Lemaire F Spontaneous hemomediastinum complicating steroid induced mediastinal lipomatosis Chest 2001; 120: 311 313 7 Shukla LW Katz JA Wagner ML Mediastinal lipomatosis: a complication of high dose steroid therapy in children Pediatr Radiol 1988; 19: 57 58 8 Sorhage F Stover DE Mortazavi A Unusual etiology of cough in a woman with asthma Chest 1996; 110: 852 854 9 Gombar S Mitra S Thapa D Gombar KK Pathak R Anesthetic considerations in steroid induced mediastinal lipomatosis Anesth Analg 2004; 98: 862 864 10 Bulakci M Yahyayev A Ucar A Erer B Erer B Dursun M Unusual cause of right ventricular outflow tract compression: mediastinal lipomatosis J Thorac Imaging 2011; 26: W134 136 11 Hsu YM Yao NS Liu JM Steroid induced mediastinal lipomatosis with radiographic features of pericardial effusion Am J Emerg Med 2000; 18: 346 348

Keywords

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Lupus nefritli bir olguda sistemik steroidlerin ender bir komplikasyonu: mediyastinal lipomatoz olgusu

Öz

Mediyastinal lipomatoz (ML), mediyastende aşırı yağ birikimine bağlı ortaya çıkan ve ender görülen bir durumdur (1). Sıklıkla endojenik ya da iyatrojenik Cushing Sendromu ya da şişmanlık ile ilişkilidir (2,3). Mediyastinal lipomatoz olguları, hiçbir klinik bulgu vermeyeceği gibi, aşırı yağ birikimine bağlı ortaya çıkan ve ciddi bası bulgularına neden olan klinik bulgularla da karşımıza çıkabilir. Ön-arka göğüs grafisinde görülen mediyastende iki taraflı genişleme en sık radyolojik bulgudur ve mediyastene ait kitleler ile karıştırılabilir (1). Kesin tanı, bilgisayarlı tomografi (BT) veya manyetik rezonans (MR) görüntüleme ile konur (4,5). Steroide bağlı ML genellikle iyi seyirlidir ve steroid dozunun azaltılması ya da kesilmesi ile geriler. Buna karşılık ciddi bası bulgularına yol açan ve cerrahi girişim gerektiren olgular literatürde bildirilmiştir (5,6). Biz de bu olgu nedeni ile sistemik steroid kullanımının ender görülen bu komplikasyonuna dikkat çekmek istedik.

Anahtar Kelimeler

• Lupus nefritli
• steroidlerin
• mediyastinal lipomatoz