Coccygeal epithelial course - anomaly of development - blindly coming to an end tubular excavation of a skin in between the cluneal cord, usually containing the lowered epithelium, Adeps and hair (a primary course). At an occlusion or disturbance of a drainage of a coccygeal course the cyst is formed, join inflammatory process, are formed purulent become numb, often opened on a skin a purulent fistula (a secondary course).

Signs, current. Mucous and purulent discharges from an ostium of a coccygeal course, a periodic exacerbation hurt in this zone with inflammatory reaction of a skin around, and sometimes with a fervescence, formation of an abscess and plural secondary purulent fistulas.