Subcutaneous tissues show many foci of dense infiltration by neutrophils, lymphocytes, macrophages, plasma cells and foreign body giant cells. Some of these foci show entrapped few hair shafts amidst the inflammatory infiltrate. Inflammation appears to extend from these foci to skin surface with formation of skin sinus. No evidence of specific granulomas. No evidence of malignancy.
Chronic pilonedal sinus
Soft tissue fragment measured 5x2x1.5 cm, partialy covered by skin in an area of 1.5x1 cm, totally embedded.
Skin lesion, Excision: