A Middle-Aged Man with Progressive Pain in the Sole of the Foot

A 52-year-old man presents to a podiatry clinic complaining of gradually worsening pain in the sole of his right foot for the past three years. He reports that the discomfort is most noticeable when walking on uneven surfaces or stepping on small objects. Recently, he has noticed a small firm nodule in the medial portion of the plantar arch, which has slowly increased in size. Occasionally, the pain wakes him up at night after prolonged standing during the day. 

He denies trauma, fever, or systemic illness. His medical and family histories are unremarkable. Vital signs are normal. On physical examination, a firm, non-mobile mass is palpated within the plantar fascia of the foot. Sensation and vascular examination of the foot are normal. MRI demonstrates a well-defined nodular lesion arising from the plantar fascia.