REPORT OF A CASE
A previously healthy 63-year-old white man presented to his local physician in December 1992 with an acute influenzalike illness. Within 1 week of beginning cephalexin therapy, he developed a pruritic rash on his back and painful oral mucosal erosions. A computed tomographic scan was ordered when he abruptly became jaundiced. Severe intrahepatic and extrahepatic biliary obstruction was noted, along with an abdominal mass, splenomegaly, and significant retroperitoneal and inguinal adenopathy.The patient was subsequently referred to the lymphoma service at the University of Texas M. D. Anderson Cancer Center, Houston, and presented January 4, 1993, with complaints of weakness, early satiety, weight loss, and a progressive blistering eruption.On physical examination, he was noted to be an ill-appearing, jaundiced man with extensive oral erosions and crusting of the lips. Numerous flaccid vesicles were observed on his trunk and thighs. Large, well-defined confluent erosions were present