When there are changes in the skin that require further examination, a punch biopsy may be useful.
First, a local anesthetic is injected or given in the form of a cream that’s applied to the area one hour before.
A small cylindrical piece of skin is removed by a special device that punches a small hole through the layers of skin to obtain a sample. Then the skin is sewn together again with a couple of stitches. This leaves a very small, almost invisible, scar.
Depending upon the result of the biopsy, the patient may be asked to return to have the whole skin lesion completely removed.
Bone marrow biopsy
A bone marrow biopsy may be necessary for many different diseases of the bone marrow, the blood and the lymphatic system. The biopsy will normally be taken from the upper part of the hip (a point called the iliac crest), but it can also be taken from the breastbone (sternum).
First, a local anesthetic is given. Then a strong needle is led through the skin and the outer part of the bone until it reaches the softer, central part of the bone (bone marrow). A syringe is put on the loose end of the needle and some bone marrow is sucked out. This sample is examined under a microscope.