Nevus comedonicus. Close-up of papules (blisters) at the bottom of the neck of a feminine patient with defect comedonicus.
Image source: SPL
defect comedonicus may be a form of growth - a benign (non-cancerous) malformation that resembles a growth (tumour). However, it grows at a similar rate because the close tissues, not like malignant (cancerous) tumours.