Lewis R. Eversole

Instances of perioral and labial foreign body reactions to a variety of injectable dermal fillers were selected from the oral and maxillofacial pathology and dermatopathology archives at Pacific Pathology Laboratory of San Diego with the objective being to engender a compilation of histopathologic characteristics that allow the pathologist to identify the inciting materials. All cases of foreign body reactions located in the lips and perioral regions were reviewed by four pathologists, retaining those cases with a history of injection lip augmentation as well as those with histologic features previously documented to represent dermal filler substances. In selected cases, Alcian blue pH 2.5 with and without hyaluronidase pretreatment was performed. Immunohistochemical markers for macrophages (CD 68), adipocytes (S-100) and keratinocytes (AE1/AE2) were undertaken. All instances presented as single or multiple submucosal plaques, nodules or swellings. Natural polymers including collagen, hyaluronate, hydroxyapatite, poly-L-lactate and synthetic polymers including carboxymethyl cellulose, dimethylpolysiloxane, and polyethyl methacrylate induce histologically unique features that allow for their identification. Host histopathologic responses included nodule without foreign body reaction, nodule with chronic inflammation, granuloma with epithelioid histiocytic and multinucleated giant cell reaction. Dermal filler foreign body host reactions in conjunction with the morphology of the foreign materials themselves are unique and can be differentiated from one another microscopically.

Sixty-five cases of odontogenic fibroma (OdonF) are herein presented having been segregated into peripheral, extra bony tumors (n = 40) and tumors arising in bone or centrally (n = 25). All cases were characterized microscopically by a fibrous proliferation that varied within and between cases in cellularity and collagen fibril diameter, with intermixed odontogenic epithelial islands and cords. All central lesions presented as well demarcated radiolucencies and resorption of contiguous tooth roots was a common finding. These intraosseous lesions were of the WHO type; the so-called nonWHO type was excluded as all lesions with this diagnosis were devoid of an epithelial component and could be reclassified as other soft tissue fibrogenic tumors. Neither the central tumors nor the peripheral lesions recurred following enucleation/curettage, with a mean follow-up of 4 and 3.4 years respectively. Three distinct microscopic variations were encountered in this series: (1) two cases of OdonF with giant cell reaction, (2) two instances of OdonF with ossifying fibroma; and (3) four instances of OdonF with odontogenic ameloblast-associated protein (ODAM), an amyloid-like protein found deposited adjacent to epithelial cords plus CD1a+/S-100+ Langerhans dendritic cells entwined around the epithelial element. A single instance of the odontogenic fibroma-like hamartoma/enamel hypoplasia syndrome has been included in this series.