ORAL WALDENSTROM MACROGLOBULINEMIA

ObjectiveWaldenstrom macroglobulinemia (WM) is a rare B-cell lymphoproliferative disorder that is characterized by bone marrow infiltration with lymphoplasmacytic cells and immunoglobulin M monoclonal gammopathy. The extramedullary infiltration of WM is uncommon but predicts a worse prognosis. To date, there has been only 1 reported case of biopsy-proven oral manifestation of WM.Case SummaryA 72-year-old man with a medical history significant for hypertension and WM, which was in good clinical and laboratory control on ibrutinib, a Bruton tyrosine kinase inhibitor, for the past 4 years, was referred by his dentist for evaluation of an asymptomatic palatal mass. The patient was known to have medication-related osteonecrosis of the jaw stage 1 of left mandible. This was secondary to Zometa prescribed to address skeletal involvement of WM. Intraoral examination demonstrated a firm, nontender, 3 × 3 cm sessile mass with surface ulcerations involving the right hard and soft palate. A panoramic radiograph did not reveal any right maxillary sinus pathology, any central lesion, or any periapical radiolucency associated with the right maxillary teeth. A biopsy of the lesion was obtained. The pathology report indicated diffuse infiltration of small to intermediate-sized lymphoplasmacytic cells within the lamina propria that were positive for B-cell markers CD19, CD20, and CD22 (on immunoperoxidase studies) with kappa light chain restriction (with in situ hybridization) confirming the diagnosis of WM. This extramedullary manifestation of WM held great importance because it indicated disease progression in the context of his current management with ibrutinib. He underwent a bone marrow biopsy that demonstrated a previously undetected Bruton tyrosine kinase mutation. He was enrolled in a Phase 1 trial of dasatinib, a tyrosine kinase inhibitor. There was almost complete resolution of the palatal mass after 6-month systemic treatment with dasatinib. However, despite noted improvement in oral WM, the patient died 7 months later.ConclusionsAlthough rare, oral health care providers should be cognizant of potential oral manifestation of WM and should communicate the findings to the oncology team because it can be of vital importance in the overall treatment plan. As in this case, the diagnosis of oral WM signified the progression of underlying malignancy.