Penile biopsy is a procedure where tissue is removed surgically to study for histopathological diagnosis. Penile biopsy is used to diagnose cancers of the penis and other benign lesions as well.
The technique used may vary with the size and location of the lesion [ for example punch biopsy or incisional/excisional biopsy.]
[Read more on types of biopsies]
Indications for Penile Biopsy
- The diagnosis of suspected penile cancer
- Histological confirmation
- Extent of invasion
- Ascertain the diagnosis in benign lesions
Penile biopsy should not be performed in a patient on anticoagulation or other blood thinners. The patient needs to stop the drugs in advance.
The type of biopsy varies with the size and location of the lesion and the suspicion of malignant disease. For lesions suspicious for cancer,
For suspicion of malignancy, various biopsy techniques are
For carcinoma in situ
- wet preparation cytology
- punch biopsy
Lesions on the shaft of the penis
- Incisional biopsy
Lesions of Prepuce
- Excisional biopsy
Apparently benign lesion
- Local excision and thorough histologic evaluation
High suspicion of malignancy
- Intraoperative frozen section followed by partial or total penectomy if malignant.
Relevant Anatomy
The penile shaft is composed of 3 erectile columns which are 2 corpora cavernosa and one corpus spongiosum.
There are additional columns of enveloping fascial layers, nerves, lymphatics, and blood vessels. All these columns are covered by skin.
Two supensory ligaments composed of primarily elastic fibers, support the penis at its base.
Procedure of Penile Biopsy
The type of biopsy performed should be predetermined to ensure that the appropriate equipment is available. The consent need to be chosen according to the procedure with the detailed explanation of risks involved. Some of the risks involved are of bleeding, infection, pain, residual tumor, and insufficient specimen.
If the intraoperative decision about the extent of surgery is to be considered, frozen section facility should be available.
The procedure is generally performed under a penile block. However, if a partial/total penectomy is to be performed [if the frozen section is positive], other relevant modes of anesthesia need be considered.
The patient is positioned in a supine position, parts are cleaned and draped with sterile drapes.
Technique of Punch biopsy
There are different sizes of punch instruments available for taking the tissue. A typical punch is 3-4 mm.
The skin around the lesion is stretched [ This is done perpendicular to the lines of least tension].
The punch is then made over the lesion and rotated wwith with a downward force.
Twisting the blade back and forth around the center axis will help to penetrate the skin.
After the skin is penetrated, there is a give away sensation.
The specimen is then removed.
Sutures may be needed for larger defects.
Incisional/excisional biopsy
An ellipse is marked around the lesion with long axis of the ellipse parallel to lines of least tension. For a good closure, the length: breadth aspect of the incision should be 3:1.
The length of the incision should be approximately 3 times the width of the incision, to provide satisfactory closure.
Marked ares is incised. Using forceps a corner is held and elevated, and ellipse excised with a scalpel or scissors.
For excisional biopsies, the care should be taken for complete removal of the ilesion.
The edges are closed and specimen preserved for histopathological studies.
References
- Soh CR, Ng SB, Lim SL. Dorsal penile nerve block. Paediatr Anaesth. 2003 May. 13(4):329-33.
- Mayeaux EJ. Essential Guide To Primary Care Procedures. Lippincott, Williams and Wilkins; 2009.