Plasmablastic Myeloma: An Unusual Cause of Peripheral Facial Paralysis

Peripheral facial paralysis refers to the involvement of the facial nerve (VII cranial nerve) at any point along its path, which starts from its nucleus, located in the pons, and extends to its most distal branches. The etiology is heterogeneous, including viral infections, bacterial infections, trauma, and neoplasms, among others. However, in the majority of cases, the cause is idiopathic, commonly referred to as Bell's palsy. The diagnosis is therefore one of exclusion, based in particular on the physical examination. Naturally, the diagnosis is decisive in directing the therapeutic approach. However, the signs/symptoms of the various primary pathological processes can appear late in the course of the disease. This is why the Physical Medicine and Rehabilitation specialist is particularly important, since, in addition to the initial assessment, he or she monitors the patient more closely and over a longer period of time, together with the team of therapists. New clinical findings and diagnostic tests requested accordingly can dramatically change the initial diagnosis and guide new treatments. We present the clinical case of a 60-year-old man initially diagnosed with Bell's palsy, whose poor clinical evolution and new clinical findings during the rehabilitation program led to the diagnosis of plasmablastic myeloma and a radically different therapeutic approach.