Caracterização histopatológica de reações adversas a materiais de preenchimento estético em região oral e maxilofacial: estudo transversal multicêntrico

Abstract

The use of aesthetic injectable materials in the orofacial region has been increasing exponentially, which has also led to an increase in complications associated with these procedures. Adverse reactions to aesthetic materials can be confused with neoplastic processes, both from a clinical and microscopic perspective. The main objective of this study is to describe in detail the clinical, demographic, histopathological, histochemical, and immunohistochemical characteristics of adverse reactions to different aesthetic fillers in the oral and maxillofacial region. A multicenter cross-sectional study was conducted, in which samples were collected from five oral pathology laboratories in Brazil and Mexico. Hematoxylin-eosin, Alcian blue, Sirius red, and toluidine blue staining, as well as immunohistochemistry for CD68, CD3, and CD20, were performed. H&E was also evaluated under polarized light. Descriptive statistics were conducted. Twenty-three cases were included. Polymethylmethacrylate was the most common material (n=10), followed by silicone (n=4), hyaluronic acid (n=3), calcium hydroxyapatite (n=3), polyacrylamide hydrogel (n=2), and poly-L-lactic acid (n=1). The patients were predominantly women (91.3%), with an average age of 50.65 years. Most reactions affected the lips and were asymptomatic, with variable evolution times (7 days to 10 years), presenting as nodules with an average size of 58.07 mm. Polymethylmethacrylate and silicone showed negative images with a rounded shape, while hyaluronic acid and polyacrylamide hydrogel presented as amorphous "pools." Calcium hydroxyapatite showed polyhedral structures, and poly-L-lactic acid exhibited fissure-like shapes. Both were birefringent under polarized light. Giant cells were commonly found, except in silicone and hyaluronic acid. Foreign body granuloma was frequent in polymethylmethacrylate. Hyaluronic acid and polyacrylamide hydrogel showed metachromasia with toluidine blue. Alcian blue was positive in all hyaluronic acid cases. Mast cells were detected in all materials except hyaluronic acid and polyacrylamide hydrogel. Eosinophils were rarer than mast cells. Numerous CD68- positive cells were seen in all cases. All cases presented CD3-positive cells, in varying amounts. CD20 was scarce or negative in most cases. In addition to the scientific article, a histopathology e-book was produced, emphasizing the histological differential diagnosis of these lesions. We conclude that despite similarities, there are specific characteristics of each material and host response that aid in the correct histopathological diagnosis. The shape, size, and staining of the material in H&E are key features in the differential diagnosis. An intense macrophage reaction is observed in all aesthetic fillers, often associated with the formation of giant cells. Immunohistochemistry for CD68 and toluidine blue staining are the most comprehensive for assisting in the correct diagnosis, although other markers may be useful in specific cases. Neoplastic lesions should also be considered in the histopathological differential diagnosis.