As per title really.
How would you differentiate a single nodule (distal to the insertion point of a classical fasciitis) and a sinister growth?
And if painful would you consider an injection of steroid?
Fusiform thickening of the full thickness of theplantar fascia immediately at the calcaneal origin = plantar fasciitis
Fusiform thickening of the full thickness of the plantar fascia not involving the area immediately at the calcaneal origin but beginniing typically 1 – 2 cm distal to this point = focal nodular fasciitis
Non fusiform thickening of the superficial fibres of the plantar fascia with preservation of the deeper fibres not involving the area immediately at the calcaneal origin but beginning typically
3 + cm distal to this point = plantar fibromatosis
I don’t really think much of “sinister” lesions in this location, however a soft tissue sarcoma can pop up anywhere so I would likely suggest an MRI if the lesion has concerning clinical features ( e.g. rapid growth and increasing pain etc) Basically anything that does not present like a typical plantar fascia pathology it is worth investigating with MRI to be sure. The fact is most are really typical so needing MRI would be uncommon.
All of these lesions can show some Doppler flow so this is not specific.