Complex sentence: He was formally diagnosed as having KS by dermatologist Marcus Conant on October 8,1981, in what would become Conant's first diagnosis of a patient with AIDS; Campbell brought Conant a rose every year to commemorate the anniversary of his diagnosis.
Split into simpler sentences: He was formally diagnosed as having KS by dermatologist Marcus Conant on October 8,1981. This would become Conant's first diagnosis of a patient with what would become known as AIDS; Campbell brought Conant a rose every year to commemorate the anniversary of his diagnosis.