We report a patient with necrotizing sarcoid granulomatosis (NSG) and point out that while the latter may have certain histological and radiological features distinct from sarcoidosis, sophisticated immunological tests show that the two disorders have essentially similar underlying immune mechanisms. We also stress that although the clinical course of NSG has been repeatedly described as benign and responsive to steroid therapy, the young patient may initially be critically ill with symptoms suggestive of an infective process rather than a granulomatous cause.