Surgical management of gingival plasma cell granuloma with histopathological and immunohistochemical confirmation through CD138 and kappa/lambda polyclonally: a case report

Plasma cell granuloma (PCG) is a benign inflammatory lesion of reactive origin that is rarely found in the oral cavity. Accurate recognition is essential to differentiate it from malignant lesions and avoid overtreatment or unnecessary radical resections. We present the case of a 26-year-old female with no systemic history who presented with an asymptomatic, firm, erythematous gingival mass in the right upper posterior sextant. The lesion was associated with subgingival dental calculus and a deep carious lesion involving the first premolar and first molar. Treatment included complete surgical excision, extraction of both teeth, and bone curettage. Histopathological examination confirmed PCG, while immunohistochemistry showed CD138 positivity (70%) and polyclonal Kappa/Lambda expression, excluding monoclonal neoplastic restriction. At the 2-month follow-up, healing was satisfactory without recurrence. Histopathological and immunohistochemical evaluation provides a definitive diagnosis, and conservative surgical management is curative.