Natural course of diffuse large B cell lymphoma—a manifestation in buccal mucosa

BACKGROUND: Transformation and progression of lymphoma after treatment is well known; however, since the advent of chemotherapy and radiotherapy, progression in untreated lymphoma is seldom seen. We present a case which was misdiagnosed and treated as abdominal tuberculosis later presented with progression and involvement of oral cavity. CASE PRESENTATION: A 41-year-old male who presented with urinary symptoms and abdominal pain was diagnosed as abdominal tuberculosis and treated. Two years later, he presented with B symptoms and oral cavity lesion that was diagnosed as diffuse large B cell lymphoma. The patient was treated with R-CHOP chemotherapy with complete regression of the lesion. CONCLUSION: Involvement of extranodal sites in predominantly nodal disease does occur; however, involvement of oral cavity is rare. Though primary extranodal lymphoma is reported to occur in oral cavity and oropharynx, natural progression in untreated disease is seldom documented.