Unveiling the Uncommon: A Rare Case of Oral Focal Mucinosis

Abstract

Background: Oral focal mucinosis is a benign and infrequently encountered oral lesion in which focal myxoid change develops within the connective tissue. Because its clinical appearance resembles several reactive and neoplastic gingival lesions, histopathological examination is important for establishing the diagnosis. Aims: This report presents an uncommon occurrence of oral focal mucinosis involving the posterior maxillary gingiva. Presentation of Case: A 20-year-old woman was evaluated for a painless swelling in the upper left posterior tooth region that had persisted for about one and a half years. Intra-oral examination identified a pink, firm, sessile, non-tender gingival overgrowth of approximately 15 × 10 mm on the palatal aspect of teeth 26–28. Periapical and occlusal radiographs demonstrated no significant underlying osseous alteration. After initial periodontal therapy, the overgrowth was excised surgically; peripheral ossifying fibroma was the provisional clinical diagnosis. Histopathology demonstrated parakeratinised stratified squamous epithelium over collagenous connective tissue containing chronic inflammatory cells, with a deeper myxoid stroma composed of delicate fibres and spindle- and stellate-shaped cells. Reticulin staining was negative. Discussion: The clinical appearance of oral focal mucinosis is nonspecific and may resemble common reactive gingival lesions, making microscopic evaluation important for differential diagnosis. Conclusion: A diagnosis of oral focal mucinosis was supported by the combined clinical, radiographic and histopathological findings. During the documented short-term follow-up, recurrence was not detected.