Radiologist wrote- lucency in distal fibula doubtful signifance (left leg). what does that mean?

A benign lesion.: Bone lesions can be 'soft' or 'hard' (lucent or sclerotic) on xrays depending on how much calcium/phosphorus content. Both types can be benign or cancerous. Radiologists evaluate a bone lesion's borders, size, location, any associated findings, number, and few other variables to determine whether it falls in the benign or malignant category. Sometimes its a normal anatomic finding as well.