Be Aware of a Potential Pitfall in Oral and Dental Specimens: Alvogyl Fibers.

Alvogyl dressing is used to help control hemostasis, foster healing, and prevent complications after certain oral procedures. It is a paste composed of different antiseptic and analgesic substances, and fern-derived Penghawar djambi fibers that have styptic properties. It is claimed to be a resorbable and self-eliminating paste with little complications. However, some studies have demonstrated detrimental effects. We report 3 cases of postextraction nonhealing sockets after Alvogyl dressing. Histologically, they demonstrated residual Alvogyl fibers with foreign body giant cell stromal reaction and complications that were clinically confused with abscess, cysts, infections, and neoplastic lesions. Being unaware of their histopathologic appearances, the foreign bodies in 2 cases were initially confused with fungal hyphae, parasitic ova, vegetable material, and other surgical and nonsurgical materials. To add to our confusion, they were periodic acid-Schiff (PAS) and Grocott methenamine silver (GMS) positive, septated, spiked, and calcified. A history of Alvogyl dressing was retrospectively found. Learning from our mistakes and being aware of the histologic manifestations of Alvogyl fibers, the third case was correctly spotted. Because Alvogyl fibers are undissolvable and are not spontaneously eliminated, they may, if left for a long period, elicit tumefactive foreign body giant cell stromal and epithelial reactions that can be confused with inflammatory, infectious, and neoplastic lesions. Histologically, they can mimic infectious agents and noninfectious materials. Because history of dressing is not always provided, pathologists should be familiar with their histomorphologic features to avoid pitfalls and guide clinicians to correct diagnosis and management. In absence of history, certain histologic features are helpful hints.