Background and Clinical Significance: Localized amyloidoma rarely affects the tongue base, a site far less commonly involved than the larynx. When it does occur at this location, the clinical and radiological presentation can closely mimic oropharyngeal malignancy, making it a genuine diagnostic pitfall for head and neck surgeons. Establishing the diagnosis demands histological proof, and ruling out systemic amyloidosis is an essential prerequisite. Case Presentation: An 80-year-old nonsmoking woman was evaluated for progressive dysphagia and globus sensation that had worsened over several years. Endoscopy revealed a firm, lobulated mass at the tongue base, centered on the glossotonsillar sulcus. Incisional biopsy under local anesthesia showed amyloid deposits. MRI demonstrated an avidly enhancing, well-circumscribed lesion without invasion of the deep neck spaces. A comprehensive systemic evaluation—including serum and urine protein electrophoresis with immunofixation, serum free light chains (κ/λ ratio 1.05), echocardiography, and bone marrow biopsy—yielded no evidence of systemic AL amyloidosis or plasma-cell dyscrasia. The mass was excised through transoral robotic surgery (TORS). Histopathology confirmed Congo red-positive, apple-green birefringent amyloid with lambda light-chain restriction; staining for AA amyloid and transthyretin was negative. The patient was diagnosed with primary localized lingual amyloidoma of the AL lambda type and remained symptom-free, with no endoscopic evidence of recurrence, at 12-month follow-up. Discussion: Amyloidoma deserves a place in the differential diagnosis of tongue base masses, particularly when the clinical picture does not fit squamous cell carcinoma. Congo red staining under polarized light, immunohistochemical light-chain typing, and a rigorous systemic workup are the cornerstones of diagnosis. Robotic-assisted transoral excision provides excellent access to the tongue base with low morbidity. Conclusions: This case underscores the need to consider amyloidoma when evaluating tongue base lesions, the central role of Congo red staining and light-chain typing, and the utility of TORS as an effective treatment option for selected symptomatic cases.
Carazo-Casas et al. (Thu,) studied this question.