A case of intraoral plasmablastic lymphoma spontaneously regressed after biopsy in HIV-negative patient

Plasmablastic lymphoma (PBL) is a rare and aggressive subtype of non-Hodgkin's lymphoma that predominantly occurs in the oral cavity of individuals infected with human immunodeficiency virus (HIV) and Epstein-Barr virus (EBV). However, it has been reported that it often occurs in HIV negative patients. In addition, although it is rare, there are cases where spontaneous withdrawal occurs without treatment. We describe a case of the PBL of oral mucosa type that occured in the mandibular gingival. The patient was a 69-year-old man who visited our hospital because of the growth of a gingival swelling in the right mandibular first molar buccal region. The swelling was identified as a spherical tumor with a smooth surface of about 10 mm in diameter. This was diagnosed clinically as a granulomatous epulis, and we performed resection biopsy to establish definite diagnosis. From the histopathological and immunohistological search of the biopsy specimen, the extract was diagnosed as PBL. The patient was HIV-negative; confirmed as a result of the blood test. Afterwards, the biopsy section followed a good healing process, and we are continuing regular follow-up observation, but we do not recognize recurrence.