Morton's Neuroma (or "Morton's metatarsalgia", or "Morton's neuralgia", "plantar neuroma" or "intermetatarsal neuroma") is a benign neuroma of the interdigital plantar nerve.
This problem is characterised by numbness and pain, relieved by removing footwear.
Although it is labeled a "neuroma", many sources do not consider it a true tumor, but rather a thickening of existing tissue.
More on [ Morton's neuroma ]

Morton's Neuroma - Information on causes and treatment from the Mayo Clinic.
Meta Description: [ Morton's neuroma — Comprehensive overview covers treatment, including surgery, of this painful foot growth. ]
Morton's Neuroma: Interdigital Perineural Fibrosis - Information from Wheelers Textbook of Orthopedics.