[Shouldn't the Achilles' heel be on the foot - regarding a clinical case].

Clinical suspicion is the bedrock of a thorough clinical work-up, and a review of the clinical files with no definitive diagnosis is a must. Such a review can uncover rare diagnoses, such as Waldenstrom's macroglobulinaemia, a proliferative B-cell disease characterised by medular infiltration and monoclonocal IgM production. 1% of these are biclonal. We present a case of a 74 year old patient diagnosed in October 2004 with acute cholecystitis. Surgical evaluation revealed bilateral pleural effusion with an inconclusive aetiology. Patient underwent a right pleurodesis in May 2005 and the aetiology remained inconclusive. The third evaluation, in July 2005, led to a final diagnosis of Waldenstrom's macroglobulinaemia.