Dermatofibroma (histiocytoma)

A der­ma­t­ofi­broma is a benign, firm nodu­le in the der­mis. It usual­ly occurs on the legs and affects women of midd­le age more fre­quent­ly. The nodu­le is harm­less and grows only very slowly.

Cau­ses

It is pro­ba­b­ly an exces­si­ve scar­ri­ng reac­tion of the con­nec­ti­ve tis­sue. Many pati­ents report a pre­ce­ding minor trau­ma such as an insect bite, a shaving inju­ry or a thorn prick. The­re is no con­nec­tion with skin cancer.

Sym­ptoms

Typi­cal is a firm nodu­le a few mil­li­me­t­res in size, skin-colou­red to red-brown, that feels hard. Cha­rac­te­ristic is the dimp­le sign: when the nodu­le is pin­ched from the sides, the skin retracts inwards. Sym­ptoms are rare, though the area occa­sio­nal­ly itches or hurts under pressure.

Tre­at­ment

As a der­ma­t­ofi­broma is benign, rem­oval is not requi­red. If the dia­gno­sis is uncer­tain, if it grows or for cos­me­tic reasons, it can be remo­ved sur­gi­cal­ly and exami­ned his­to­lo­gi­cal­ly. It should be noted that this lea­ves a scar which may be lar­ger than the ori­gi­nal nodule.