Dermatomyositis as the First Manifestation of Nasopharyngeal Carcinoma-A Rare Case Report

Nasopharyngeal carcinoma (NPC) with paraneoplastic dermatomyositis (DM) is an exceptionally rare clinical phenomenon, particularly among European populations. This case report details a 46-year-old woman initially diagnosed with DM, later confirmed to have NPC. Such an association is more frequently documented in Asian populations, highlighting its unique presentation in this case. The patient first developed symptoms in December 2016, which progressed significantly by spring 2017, manifesting as progressive proximal muscle weakness, characteristic skin changes, and elevated muscle enzyme levels. Diagnostic workup, including electromyography and biopsy, confirmed DM. Persistent symptoms and secondary DM suspicion prompted further malignancy screening, which identified undifferentiated NPC with strong Epstein-Barr virus RNA positivity. Multimodal treatment comprising corticosteroids, hydroxychloroquine, chemotherapy, and radiotherapy led to temporary symptomatic improvement. Despite initial success, the patient's condition deteriorated, and she passed away by the end of 2018. This case underscores the importance of comprehensive malignancy screening in DM patients, considering rarer cancers like NPC even in non-endemic regions. It emphasizes the role of multidisciplinary care and adherence to international guidelines for managing such complex cases. Recognizing NPC-associated DM remains critical for early intervention and tailored therapeutic approaches to improve clinical outcomes and survival.