Abstract
BACKGROUND: Paraneoplastic pemphigus (PNP) is a rare, life-threatening autoimmune bullous disease. Among the ≈500 reported cases of PNP, only 1 case has been associated with tonsillar cancer, specifically, human papillomavirus (HPV)-positive squamous carcinoma. However, the occurrence of PNP in non-HPV-related tonsillar cancer is exceptionally rare and has not been reported to date. METHODS: We present a 58-year-old male with a history of smoking, who experienced recurrent oral ulcers, right neck swelling, and hoarseness for 5 months. Diagnosis of right tonsillar squamous cell carcinoma (cT1N3bM0) was confirmed through computed tomography/magnetic resonance imaging and pathology, not associated with HPV. Histological and immunohistochemical findings indicated PNP. RESULTS: The patient underwent primary tumor resection and ipsilateral neck dissection. Topical steroids and antifungal agents were administered to manage oral lesions and prevent secondary infections. Adjuvant concurrent chemoradiotherapy with cisplatin proceeded smoothly. Postconcurrent chemoradiotherapy follow-up at 3, 6, and 9 months, utilizing computed tomography/magnetic resonance imaging and nasopharyngoscopy, revealed no signs of recurrent cancer or PNP. CONCLUSION: Early indicators, such as oral mucosal ulcers and skin blisters, prompt consideration of underlying oral cancer in PNP. Comprehensive examination is crucial for diagnosing PNP and identifying concurrent internal neoplasms. Effective management includes occult malignancy treatment, postoperative steroid therapy, and infection prevention.