SKIN (Natal cleft) - Pilonidal sinus

The specimen is a block of skin and subcutaneous fat from the natal cleft. Just to one side of the midline there is a slightly raised area on the surface of the skin leading down into a track surrounded by tan-coloured tissue. On the reverse of the specimen a smaller track can be seen surrounded by pale scar tissue.
This presented as a painless lump in the sacral area of a man aged 33. On several occasions pus was discharged from the sinus. The lesion was excised but recurred later and further excision was needed.