The papilliferous surface is considered to result from exposure to the hemodynamic stress of flowing blood.[1,4] Lambl excrescences origin was suggested, but most authors believe that PFE is a separate entity. Other theories suggest that PFEs represent neoplasms, hamartomas, and inflammatory nodules.[4,7]
The differential diagnosis of PFE includes other papilliferous lesions of the heart, such as myxomas, Lambl excrescences, bacterial vegetations, and organizing marantic (thrombotic) endocarditis.[6,8] Myxomas most frequently originate from the wall of the left or right atrium and are rarely located on the valve surface.
Not every sebaceous nevus advances to the third stage, which is characterized by the transformation of skin appendages into secondary neoplasms--namely, papilliferous syringadenomas and basal cell carcinomas.
(3, 4) Jones and Heyl studied 140 cases of sebaceous nevi and found that nearly 20% transformed into papilliferous syringadenomas.