Neuroma

A neuroma is a benign tumor of nerve tissue, though the term sometimes refers to a proliferation of nerve tissue without true neoplastic growth. Morton’s neuroma, the most common type, is a compression neuropathy of the interdigital nerve in the foot, typically between the third and fourth metatarsal heads. On ultrasound, Morton’s neuroma appears as a hypoechoic to isoechoic nodule in the interdigital space that may show hypoechoic swelling of the nerve proximal to the mass. Compressing the transducer can sometimes reproduce the patient’s symptoms (the Mulder click). While ultrasound can detect and characterize neuromas, their appearance is not entirely specific, and clinical correlation is important for diagnosis.