Abstract
Inflammatory pseudotumor of the nasopharynx is a rare diagnosis that is often misinterpreted as carcinoma or lymphoma. It has been referred to as a tumefactive fibroinflammatory lesion, idiopathic pseudotumor, and fibrosing inflammatory pseudotumor. We present a rare case of a 40-year-old African American female from Kenya with inflammatory pseudotumor of the nasopharynx with perineural spread of disease along the trigeminal nerve to discuss the diagnosis and treatment of such an uncommon entity.
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Introduction
Inflammatory pseudotumor of the nasopharynx is a rare diagnosis that is often misinterpreted as carcinoma or lymphoma. It has been referred as a tumefactive fibroinflammatory lesion, idiopathic pseudotumor, and fibrosing inflammatory pseudotumor. We present a rare case of a 40-year-old African American female from Kenya with inflammatory pseudotumor of the nasopharynx with perineural spread of disease along the trigeminal nerve to discuss the diagnosis and treatment of such an uncommon entity.
A 40-year-old African American female from Kenya presents with 2 weeks of a left-sided headache accompanied by facial and ear pain, nasal congestion, and numbness in the left upper face. The patient denied any palpable lymphadenopathy, fevers, bloody nasal discharge, or difficulty swallowing. There were no significant laboratory abnormalities. An unenhanced CT of the head ordered by the general practitioner demonstrated a left-sided mastoid effusion and a partially imaged nasopharyngeal mass. A gadolinium-enhanced MRI of the neck was subsequently ordered. This showed a 2.2 (AP) × 2.0 (TV) × 4.3 (CC)-cm mass in the left posterior nasopharyngeal soft tissues with posterior extension into the superomedial aspect of the lateral pterygoid muscle and nodular enhancement extending along the third division of the trigeminal nerve, through the foramen ovale, to the inferior aspect of Meckel’s cave ( Figs. 1 and 2 ). The primary diagnostic considerations at this time were nasopharyngeal carcinoma and lymphoma.
The patient initially chose to follow up at an outside institution where a core biopsy was performed. The biopsy contained an atypical lymphoid infiltrate but was inconclusive. She was then referred to our oncology clinic for further management. A fused PET/CT scan was obtained which revealed a hypermetabolic focus corresponding to the previously identified nasopharyngeal mass. No additional metabolic foci were present. A fine needle aspiration was then performed. The results showed acute inflammation with occasional lymphoid aggregates. Flow cytometry was negative for atypical lymphoid population. Since the imaging characteristics were highly suggestive of malignancy, additional tissue sampling via surgical excisional biopsy was performed. The pathology was reviewed in conjunction with the Mayo Clinic and the results showed acute on chronic inflammation with fibrosis and polytypic plasmacytosis.
The patient was initially treated with dexamethasone resulting in symptomatic improvement of the pain and numbness. She then received 7 weeks of high-dose (60 mg) prednisone with further but incomplete response both clinically and radiologically. Intensity-modulated radiation therapy (IMRT) was then used to administer 40 Gy to the nasopharynx delivered as 30 Gy at 2 Gy per day followed by a 10-Gy boost. The treatment was well tolerated and finished with complete symptom resolution. A 14-month post-treatment MRI demonstrated less conspicuous enlargement of the left lateral and medial pterygoid musculature and persistent enhancement of the left cavernous sinus and left foramen ovale ( Figs. 3 and 4 ).
