Craniofacial extramedullary plasmacytoma with hard palate and bilateral cervical lymph node involvement: a diagnostic challenge and literature review

Extramedullary plasmacytoma (EMP) is a rare plasma cell tumor primarily affecting extramedullary sites without involving the bone marrow. While 80–90% of cases occur in the head and neck regions, craniofacial EMP involving the hard palate and spreading to bilateral cervical lymph nodes is exceptionally rare. A 59-year-old female presented with a one-year history of a nasal mass on the right anterior side. Her medical history showed basal cell carcinoma and oropharyngeal tumors. Physical examination revealed a mulberry-like mass in the right nasal vestibule. Computed tomography (CT) of the paranasal sinus revealed a space-occupying lesion in the nasal cavity. The patient underwent surgical resection, with histopathological and immunohistochemical analysis confirming plasmacytoma. Bone marrow aspiration and biopsy showed no significant abnormalities. Subsequent positron emission tomography-computed tomography (PET-CT) identified involvement of bilateral cervical lymph nodes and the hard palate. This was confirmed by CT-guided fine-needle aspiration biopsy, with pathological results consistent with those of the nasal lesion. The final diagnosis was EMP involving the hard palate and bilateral cervical lymph nodes. The patient underwent four cycles of chemotherapy using the VCD regimen (bortezomib, cyclophosphamide, dexamethasone), followed by localized radiotherapy (36 Gy in 18 fractions). Currently, she shows no evidence of systemic involvement and is recovering well. We report a rare case of primary sinonasal EMP with involvement of the hard palate and bilateral cervical lymph nodes. Due to its non-specific clinical features, sinonasal EMP is often misdiagnosed as other head and neck malignancies. Pathological biopsy is crucial for definitive diagnosis. Treatment should be individualized based on disease extent, including surgery, radiotherapy, and systemic therapies as appropriate.