Extramedullary Plasmacytoma of the Base of Tongue: A Case Report

Abstract

Introduction: Extramedullary plasmacytoma (EMP) is a rare plasma cell neoplasm typically arising outside the bone marrow. EMP involving the base of the tongue is particularly uncommon, posing diagnostic and therapeutic challenges due to its rarity and nonspecific presentation.

Case presentation: A 65-year-old male presented with progressive dysphagia, odynophagia, and significant weight loss. Biopsy of a tongue base mass initially suggested a high-grade hematolymphoid neoplasm, subsequently confirmed as EMP on secondary pathology review. Positron emission tomography-computed tomography (PET/CT) imaging revealed localized fluorodeoxyglucose-avid involvement of the tongue base and bilateral cervical lymph nodes. Bone marrow biopsy was negative for systemic disease. The patient was treated with definitive radiation therapy, resulting in complete clinical and radiologic resolution of disease on follow-up PET/CT 3 months posttreatment. Surveillance studies showed no progression to multiple myeloma.

Conclusion: Clinicians should maintain a high index of suspicion for EMP in patients presenting with persistent oropharyngeal symptoms and atypical masses. Early recognition and definitive radiation therapy can lead to excellent outcomes and prevent progression to systemic disease.

Keywords: Base of tongue; Cervical lymphadenopathy; Dysphagia; Extramedullary plasmacytoma; Nodal involvement; Oropharyngeal neoplasm; Radiation therapy.

Fig. 1.

Visual summary of the case in sequential order.

Fig. 2.

a Pretreatment laryngoscopy of the oropharynx. Plasmacytoma can be seen located at the base of the tongue and adjacent to the epiglottis. b Posttreatment laryngoscopy of the oropharynx showing excellent response to treatment and regression.

Fig. 3.

PET/CT left and right axial cross-sections depicting bilateral cervical lymph node involvement. Across the top row is the status pre radiation therapy, while the bottom row shows 3-month status post radiation therapy.

Fig. 4.

PET/CT coronal, transverse, and sagittal cross-sections revealing an FDG-avid lesion in the region of the tongue base. Across the top row is the status pre radiation therapy, while the bottom row shows 3-month status post radiation therapy.