|
Indian Journal of Medical Sciences, Vol. 59, No. 6, June, 2005, pp. 268-271 Case Report Idiopathic mediastinal fibrosis presenting as mediastinal compression syndrome Patil Prashant L., Salkar H.R. Department of Medicine, Government Medical College, Nagpur Code Number: ms05041 ABSTRACT Mediastinal compression syndrome is a commonly seen entity. Mediastinal compression, mostly due to a space-occupying lesion, is distinct and different from mediastinitis/mediastinal fibrosis, which could also lead to superior vena cava syndrome. Idiopathic mediastinal fibrosis should also be considered as differential diagnosis of mediastinal structures with various radiological, CT and MRI and histological features if feasible. Medical therapy is disappointing while surgical cure has limitations. This interesting patient presented as mediastinal compression syndrome, which on investigation was postulated as idiopathic mediastinal fibrosis, as a diagnosis on exclusion of other causes, which is rare, hence is being reported.Keywords: Fibrosis, mediastinitis, mediastinal fibrosis INTRODUCTION Idiopathic mediastinal fibrosis is also known as Chronic Fibrosis or Fibrosing Mediastinitis or Chronic Mediastinal Fibrosis or Cryptogenic Mediastinal Fibrosis, all terms suggestive of slowly progressive envelopment of mediastinal structures in proliferating fibrous scar tissue. Osler in 1903 published the first major review on mediastinal fibrosis,[1] since then a few case series[2],[3] have been published with stray case reports.[4],[5],[6] Mediastinal structures are surrounded, constricted and sometimes invaded by the fibrous tissue, which may extend to affect other intrathoracic organs. The pattern of involvement of mediastinum is variable and so are the clinical features.[2] Venous
structures (Superior Vena Cava and Pulmonary veins), due to thin walls
and low intraluminal pressure, tend to be compressed earlier than are
the arteries and tracheobronchial tree and esophagus. For this reason
venous hypertension in the drainage area of superior vena cava is considered
the hallmark of the disease. It is a rare cause of superior vena cava
obstruction (1-2%).[4] Various hypotheses have been proposed for the fibrous lesions.[7] Case history A 30-year-old male, rickshaw-puller by occupation presented with puffiness of face and swelling over both upper limbs, more after getting up in the morning since 2 years. He also had noticed dyspnoea on exertion and dull aching diffuse chest pain since 2 years and had cough with scanty mucoid-white expectoration since 4 months. There was no history of fever, hemoptysis, edema feet, urinary complaints, dysphagia, nausea or vomiting, change in voice, palpitation. Past history was not contributory. There was no history of drug intake or exposure to radiation. Personal and family history was not contributory.This average built man had suffused conjunctiva, face and both upper limbs. The vital parameters were normal. The jugular veins were full and nonpulsatile, prominent veins were seen over arms, chest and anterior aspect of neck with flow away from mediastinum. No edema feet. Respiratory system examination revealed bilateral ronchi and crepitations. Examination of other systems was normal. On investigation his hemogram, urine analysis, renal and liver function tests, ECG and 2-D-ECHO were normal. Sputum for acid-fast bacilli, malignant cells, and fungus culture was negative. The X-ray chest showed mild superior mediastinal widening. Computerized tomography of chest showed multiple abnormal vessels in superior mediastinum. Abnormally dilated azygous vein and small vascular structure in the region of SVC. There was no evidence of mediastinal mass or lymphadenopathy. Venography of upper extremity revealed bilateral collaterals. Superior Vena Cava was not visualized. Mediastinoscopy, mediastinotomy or histopathological confirmation could not be done due to refusal for consent to undergo invasive interventions/procedure. DISCUSSION The first description of idiopathic mediastinal fibrosis is ascribed to John Hunter in 1757 while others prefer the description written by Hallet of Edinburgh in 1948. The pathogenesis as reflected by the term ′Idiopathic′ is unknown. The various hypotheses postulated for the fibrous lesions are as follows:
There is no gender predilection and it affects all ages, usual age of onset is fourth decade. In a typical case initially puffiness of face is noticed especially after getting up in the morning. The lower parts of body and legs are normal. Followed by effects of superior vena cava obstruction in the form of dusky color of face, neck, and arms, suffusion of conjunctiva and telangiectasia, dyspnoea, giddiness, tinnitus, headache, epistaxis, or hemoptysis - aggravated by coughing, straining, stooping or exercise. After about 6-9 months and as the years pass, there may be a progressive relief of symptoms, but the patient never becomes free of disability. Investigations suggestive of idiopathic mediastinal fibrosis are mediastinal widening on X-ray chest, barium swallow and bronchoscopy may show areas of compression or distortion, which may be seen on computerized tomography of chest.[9] Venogram showing collaterals and mediastinal veins are diagnostic. Mediastinoscopy, mediastinotomy may be difficult and histopathology may be confirmative and requires large sample of tissue if obtained surgically though rarely CT guided automated needle biopsy may be possible.[10] Our patient presented with features of superior vena cava obstruction for which no clinical or radiological cause could be demonstrated, hence a possibility of idiopathic mediastinal fibrosis was entertained as a diagnosis on exclusion of common causes, which was supported by a positive venogram study of the upper extremity. Medical therapy with diuretics, Anticoagulants, Steroids and penicillamine has been disappointing. Palliative surgery for SVC obstruction in form of autogenous Saphenous vein graft, woven silicon rubber prosthesis and bovine pericardial conduits for venous reconstruction are recommended along with dilatation of bronchial and esophageal strictures.[7] Stenting of vessels, bronchi and esophagus can be of some help.[5] The immediate and ultimate risk to life is small. But the inconvenience is considerable and sustained. As the time passes the development of venous collateral circulation mollifies some of the distress, but the clinical state never returns to normal unless the mechanical obstruction can be overcome. REFERENCES
Copyright 2005 - Indian Journal of Medical Sciences |
|