Plasma Cell Gingivitis With Cheilitis in an Adolescent: A Case Report

Plasma cell gingivitis (PCG) is an uncommon plasma-cell-rich inflammatory disorder of the gingiva that may clinically resemble plaque-associated enlargement, granulomatous disease, hematologic disease, or plasma-cell neoplasia. Its association with cheilitis is rare, and diagnosis requires clinicopathologic correlation. An 18-year-old female presented with a 1-year history of progressive gingival enlargement and upper-lip swelling. Intraoral examination showed generalized erythematous marginal and papillary gingival enlargement with loss of stippling, bleeding on probing, pseudopocketing, and firm consistency. Extraoral examination showed diffuse, soft, non-tender swelling of the upper lip measuring approximately 1 × 3 cm. The initial clinical differential diagnosis included orofacial granulomatosis and puberty-associated gingival enlargement. Hematological screening showed anemia but did not show findings suggestive of leukemia or systemic infection. Incisional biopsy showed parakeratinized stratified squamous epithelium with pseudoepitheliomatous hyperplasia and a plasma-cell-rich inflammatory infiltrate composed of cytologically mature plasma cells without cytological atypia. Immunohistochemistry for kappa and lambda light-chain expression was not performed. The patient had an inadequate response to non-surgical periodontal therapy and topical corticosteroids and was subsequently managed with gingivectomy. No disease-directed adjuvant therapy was administered after gingivectomy. At the one-month postoperative follow-up, both the gingival enlargement and upper-lip swelling had regressed. This case highlights the importance of biopsy and hematological screening in persistent gingival enlargement with associated cheilitis, particularly when clinical findings overlap with systemic or neoplastic mimics.