Skin Biopsies and Skin Lesions

Skin biopsy is a biopsy technique in which a skin lesion is removed and sent to the pathologist to render a microscopic diagnosis. It is usually done under local anesthetic in a physician’s office, and results are often available in 4 to 10 days. It is commonly performed by dermatologists.

Skin biopsies are also done by family physicians, internists, surgeons, and other specialties. However, performed incorrectly, and without appropriate clinical information, a pathologist’s interpretation of a skin biopsy can be severely limited. There are four main types of skin biopsies: shave biopsy, punch biopsy, excisional biopsy, and incisional biopsy. The choice of the different skin biopsies is dependent on the suspected diagnosis of the skin lesion.

Like most biopsies, patient consent and anesthesia (usually lidocaine injected into the skin) are prerequisites.

Different types of skin biopsies

Shave biopsy

This is done with either a small scalpel blade, a curved razor blade, or a broken piece of “safety” razor. The technique is very much user skill dependent, as some surgeons can remove a small fragment of skin with minimal blemish using any one of the above tools, while others have great difficulty securing the devices. Ideally, the razor will shave only a small fragment of protruding tumor and leaving the skin relatively flat after the procedure. Hemostasis is obtained using light electrocautery, Monsel solution, or aluminum chloride. This is the ideal method of diagnosis for basal cell
cancer.

It can be used to diagnose squamous cell carcinoma and melanoma-in-situ, however, the doctor’s understanding of the growth of these last two cancers should be considered before one uses the shave method. The punch or incisional method is better for the latter two cancers as a false negative is less likely to occur (i.e. calling a squamous cell cancer an actinic keratosis or keratinous debris). Hemostasis for the shave technique can be difficult if one relied on electrocautery alone. A small “shave” biopsy often ends up being a large burn defect when the surgeon tries to control the bleeding with electrocautery alone. Pressure dressing or chemical astringent can help in hemostasis in patients taking anticoagulants.

Punch biopsy

This is done with a round shaped knife ranging in size from 1mm to 8 mm. Some punch biopsies are shaped like an ellipse, although one can accomplish the same desired shape with a standard scalpel. The 1 mm and 1.5 mm punch are ideal for locations where cosmetic appearance is difficult to accomplish with the shave method. Minimal bleeding is noted with the 1 mm punch, and often the wound is left to heal without stitching for the smaller punch biopsies. Disadvantage of the 1 mm punch is that the tissue obtained is almost impossible to see at times due to small size, and the 1.5 mm biopsy is preferred in most cases. The common punch size use to diagnose most inflammatory skin condition is the 3.5 or 4 mm punch. Ideally, the punch biopsy include the full thickness skin and subcutanous fat in the diagnosis of skin disease

Incisional biopsy

When a cut is made through the entire dermis down to the subcutanous fat. A punch biopsy is essentially an incisional biopsy, except it is round rather than elliptical as in most incisional biopsies done with a scalpel. Incisional biopsies can include the whole lesion (excisional), part of a lesion, or part of the affected skin plus part of the normal skin (to show the interface between normal and abnormal skin). Incisional biopsy often yield better diagnosis for deep pannicular skin diseases and more subcutanous tissue can be obtained than a punch biopsy. Long and thin deep incisional biopsy are excellent on the lower extremities as they allow a large amount of tissue to be harvested with minimal tension on the surgical wound. Advantage of the incisional biopsy over the punch method is that hemostasis can be done more easily due to better visualization. Dog ear defects are rarely seen in incisional biopsies with length at least twice as long as the width.

Excisional biopsy

This is essentially the same as incisional biopsy, except the entire lesion or tumor is included. This is the ideal method of diagnosis of small melanomas (when performed as an excision). Ideally, an entire melanoma should be submitted for diagnosis if it can be done safely and cosmetically. This “excisional” biopsy is often done with a narrow margin to make sure the deepest thickness of the melanoma is given before prognosis is decided. However, as many melanoma-in-situs are large and on the face, a physician will often chose to do multiple small punch biopsies before committing to a large excision for diagnostic purpose alone. Many prefer the small punch method for initial diagnostic value before resorting to the excisional biopsy. An initial small punch biopsy of a melanoma might say “severe cellular atypia, recommend wider excision”. At this point, the clinician can be confident that an excisional biopsy can be performed without risking committing a “false positive” clinical diagnosis.

Curettage biopsy

This can be done on the surface of tumors or on small epidermal lesions with minimal to no topical anesthetic using a round curette blade. Diagnosis of basal cell cancer can be made with some limitation, as morphology of the tumor is often disrupted. The pathologist must be informed about the type of anesthetic used, as topical anesthetic can cause artifact in the epidermal cells. Liquid nitrogen or cryotherapy can be used as a topical anesthetic, however, freezing artifact can severely hamper the dianosis of malignant skin cancers.

Fine needle aspirate

Needle aspiration biopsy[1] is done with the rapid stabbing motion of the hand guiding a needle tipped syringe and the rapid sucking motion applied to the syringe. It is a method used to diagnose tumor deep in the skin or lymphnodes under the skin. The cellular aspirate is mounted on a glass slide and immediate diagnosis can be made with proper staining or submitted to a laboratory for final diagnosis. A fine needle aspirate can be done with simply a small bore needle and a small syringe (1 cc) that can generate rapid changes in suction pressure. Fine needle aspirate can be used to distinguish a cystic lesion from a lipoma. Both the surgeon and the pathologist must be familiar with the method of procuring, fixing, and reading of the slide. Many center have dedicated team used in the harvest of fine needle aspirate.

Saucerization biopsy

Also known as “scoop”, “scallop”, or “shave” excisional biopsy[2], or “shave” excision. A trend has occurred in dermatology over the last 10 years with the advocacy of a deep shave excision of a pigmented lesion [3] [4] [5] An author published the result of this method and advocated it as better than standard excision and less time consuming. The added economic benefit is that many surgeons bill the procedure as an excision, rather than a shave biopsy. This saves the added time for hemostasis, instruments, and suture cost. The great disadvantage, seen years later is the numerous scallop scars, and a very difficult to deal with lesions called a “recurrent melanocytic nevus”, see recurrent nevus. What has happened is that many “shave” excisions do not adequately penetrate the dermis or subcutanous fat enough to include the entire melanocytic lesion. Residual melanocytes regrow into the scar. The combination of scarring, inflammation, blood vessels, and atypical pigmented streaks seen in these recurrent nevus gives the perfect
dermatoscopic picture of a melanoma[6][7][8][9]. When a second physician re-examines the patient, he or she has no choice but to recommend the reexcision of the scar.

If one does not have access to the original pathology report, it is impossible to tell a recurring nevus from a severely dysplastic nevus or a melanoma. As the procedure is widely practiced, it is not unusual to see a patient with dozens of scallop scars, with as many as 20% of the scar showing residual pigmentation. The second issue with the shave excision is fat herniation, iatrogenic anetoderma, and hypertrophic scarring. As the deep shave excision either completely removes the full thickness of the dermis or greatly diminishes the dermal thickness, subcutanous fat can
herniate outward or pucker the skin out in an unattractive way. In areas prone to friction, this can result in pain, itching, or hypertrophic scarring.

The Pathology Report

A pathology report is highly dependent on the quality of the biopsy that is submitted. It is not unusual to miss the diagnosis of a skin tumor or a skin biopsy due to a poorly performed or inappropriately performed skin biopsy. The clinical information provided to the pathologist will also affect the final diagnosis. An example would be a rapidly growing dome shaped tumor of the sun exposed skin. Despite doing a large wedge incision, a pathologist might call the biopsy keratin debris with characteristics of actinic keratosis. But provided with an accurate clinical information, he/she might consider the diagnosis of a well differentiated squamous cell carcinoma or keratoacanthoma. It is not infrequent for two, three or more biopsies to be performed by different doctors for the same skin condition, before the correct diagnosis is made on the final biopsy.

The method, depth, and quality of clinical data will all affect the yield of a skin biopsy. For this reason, doctors specializing in skin diseases are invaluable in the diagnosis of skin cancers and difficult skin diseases. Specific stains (PAS, DIF, etc), and certain type of sectioning (vertical and horizontal) are often requested by an astute physician to
make sure that the pathologist will have all the necessary information to make a good histological diagnosis.

References

1. ^ http://www.virtualcancercentre.com/investigations.asp?sid=3
2. ^ Saucerization biopsy of pigmented lesions . Clinics in Dermatology , Volume 23 , Issue 6 , Pages 631 - 635 J . Ho , R . Brodell , S . Helms
3. ^ http://escholarship.umassmed.edu/ssp/46/
4. ^ http://www.clinmedres.org/cgi/content/full/6/2/86
5. ^ http://www.aafp.org/afp/20021101/letters.html
6. ^ http://www.springerlink.com/content/u353473367570111/
7. ^ http://www.pathology-skin-rjreed.com/html/recurrent_nevus__c20t3_.htm
8. ^ http://dermoscopic.blogspot.com/2007/11/recurrent-nevus.html
9. ^ http://www.pathology-skin-rjreed.com/congenital_nevust_c7bt2_.HTM

Using Anticoagulants During Cutaneous Surgery

Anticoagulants and Blood Thinners During Cutaneous Surgery: Always, Sometimes or Never?

C. F. Schanbacher, MD

Dana-Farber Cancer Institute, Brigham and Woman’s Hospital, Harvard Medical School, Boston, MA, USA

ABSTRACT

There is no consensus with regard to perioperative blood thinner management in patients undergoing cutaneous procedures. The rationale and problems associated with blood thinners during cutaneous surgery are examined and the preoperative screening and surgical management of patients taking anticoagulant medicines discussed. There are many studies that support continuation of blood thinners during cutaneous procedures supporting the conclusion that blood thinners should not be discontinued for cutaneous procedures.
Key Words: blood thinners, cutaneous surgery

Anticoagulant medicines are used to treat individuals at risk for primary or recurrent thromboembolism. During major procedures, such as intraabdominal, intracranial, orthopedic or cardiothoracic, blood thinning agents are usually discontinued or at least modified in an attempt to prevent undue intraoperative and postoperative bleeding. Subsequent to such procedures, blood thinners are reintroduced to treat the underlying thromboembolic disorder. This process of manipulating the level of anticoagulation can be time consuming, requires multiple blood tests and exposes patients to increased risk of thromboembolism, hemorrhage or both.

Patients at risk for thromboembolic events include those with mechanical heart valve(s), valvular heart disease, underlying coagulopathy, atrial fibrillation, history of stroke, pulmonary embolism, myocardial infarction, or deep venous thrombosis. Commonly prescribed anticoagulant medicines include antithrombin agents such as warfarin or heparin products, and antiplatelet agents such as aspirin, thienopyridines or glycoprotein IIb/IIIa inhibitors (Table 1). Patients at risk for thromboembolism typically take one or more of the aforementioned anticoagulants under the guidance of the primary care provider.

Table 1: Antithrombotic agents approved in the U.S. Modified from Alam M, Goldberg LH.¹

Historically, dermatologic surgeons have implemented general surgery practice guidelines in managing blood thinning medicines prior to and during cutaneous procedures. Based on advice given for previous surgery, some patients undergoing cutaneous surgery stop anticoagulation medicines themselves without consulting a physician. Other patients stop anticoagulant medicines on the advice of their referring physician, surgeon or both. Frequently patients on long-term anticoagulation arrive for their cutaneous procedures without the protection afforded by their vital blood thinning medicines. Thromboenbolic events have been reported in cutaneous procedure patients whose anticoagulants were stopped in order to limit ostensible perioperative bleeding.² A recent survey of 168 Mohs micrographic surgeons reported 46 patients who experienced thromboembolic events, including three deaths and 24 strokes after brief perioperative blood thinner cessation.3 Fifty-four percent of the thromboembolic events occurred after warfarin was discontinued and 39% had thromboembolism after aspirin was withheld.³ Discontinuation of newer blood thinners such as ticlopidine, clopidogrel and ardeparin has also been associated with thromboembolism.¹

A retrospective study of 653 patients undergoing cutaneous procedures was performed by Otley, et al in 1996. Some of the patients had their blood thinners (antiplatelet agent or warfarin) discontinued preoperatively. The risk of severe intraoperative and postoperative bleeding in patients taking blood thinners was found very low, not significantly reduced by preoperative blood thinner discontinuation.⁴ Several recent studies have documented that cutaneous procedure patients taking aspirin have no significant risk of postoperative hemorrhagic complications.^5-7 Others have reported no significant risk of postoperative hemorrhage in cutaneous surgery patients taking therapeutic doses of warfarin.^8,9 Furthermore, successful procedures in patients taking therapeutic levels of warfarin without undue postoperative bleeding have been documented in many surgical subspecialties, including cardiothoracic, gastrointestinal, urology, oromaxillofacial, vascular, and ophthalmology.

Cutaneous surgeons may cite anecdotal experience as grounds for blood thinner discontinuation. Some surgeons believe blood thinners cause undue intraoperative bleeding, which interferes with operative dissection. Perceiving undue intraoperative bleeding, the surgeon may inquire as to whether the patient has recently taken blood-thinning medicines. A recent study by West, et al showed that cutaneous surgeons are unable to accurately predict blood thinner status of the patient based on intraoperative oozing.¹⁰ This study helped to dispel some of the myths associated with blood thinners in the setting of cutaneous surgery.

I do not advise my patients undergoing cutaneous procedures to discontinue any blood thinner used to treat a thromboembolic disorder. The following techniques may prove helpful in screening and treating cutaneous surgery patients, many of whom take one or multiple blood thinning medicines.

Preoperative Screening

1. Ask patient about bleeding complications from past procedures (dental extraction, teeth cleaning, invasive surgery). Inquire if they have experienced spontaneous bleeding (GI bleeding, epistaxis) or a large hematoma after relatively minor trauma. Does the patient bleed for a prolonged period after minor cuts and scratches?
2. Routine preoperative INR, bleeding time, and prothrombin (PT) are not usually helpful in predicting operative and postoperative bleeding. Determine if patient has had erratic International Normalized Ratio (INR) values in the past. If values are supratherapeutic (INR>5), the risk of postoperative bleeding increases significantly.
3. Inquire about other conditions that may contribute to bleeding: alcoholism, liver disease, inheritable coagulopathies (hemophilia, Von Willebrand’s disease), acne rosacea, and the use of other anticoagulants that could potentiate bleeding such as vitamin E, Ginko biloba, and nonsteroidal anti-inflammatory drugs.
4. Some patients take empiric aspirin and have no obvious underlying risk of thromboembolism. Many of these patients take aspirin at the advice of friends, family or primary care provider. It is reasonable to temporarily stop such empiric aspirin intake.
5. If patient has a history of severe postoperative bleeding complications, consider non-surgical modalities such as radiation.

Operative Techniques

1. Meticulous homeostasis is vital in managing cutaneous surgery patients taking blood thinners. Make sure to have excellent lighting and wound retraction to assist isolating arteriole bleeding. Use a hemostat to grasp and close the vessel. Secure vessel closed with absorbable ligature. Employ electrocoagulation. If automatic implantable cardioverter defibrillator (AICD) or pacemaker is present, use bipolar forceps to stop small vessel bleeding.
2. Simplify wound reconstruction. Discuss simplifying the reconstruction with the patient. Review the risks of a more noticeable scar vis-à-vis the need for continued anticoagulation. A flap, which may mobilize large amounts of skin, is probably at greater risk for hematoma and wound necrosis. Pursestring closures may work well to minimize postoperative hemorrhage. A purse-string closure does not require undermining and serves to tamponade peripheral wound bleeding. The center of the wound remains open and acts as a drain.
3. Limit subcutaneous undermining. In severe cases, when patients have repeatedly soaked through the dressing whilst in the waiting room, I have closed wounds primarily without any undermining, limiting potential bleeding foci. Close the wound meticulously with multiple layers of absorbable suture to minimize dead space.
4. Second intention healing is also a reasonable choice for wound management. In addition, one may apply Gelfoam® to the wound and secure a pressure dressing over the Gelfoam®. In severe cases, the surgeon can also run absorbable suture such as 5-0 Monocryl®‚ continuously around the wound edges.
5. Fenestrated full thickness skin grafts with a tie-over bolster provide wound tamponade and a collagen substrate for hemostasis.
6. During wound repair, consider using local anesthesia without a vasoconstrictor, such as epinephrine. Vasoconstrictors provide helpful operative bleeding reduction, prolong anethesia duration and reduce total anethetic dose. However, reactive vasodilatation in the postoperative period may predispose to hematoma because potential bleeding points, such as arterial bleeding, are not recognized at surgery.¹¹
7. Drains: in cases where refractory bleeding may continue as a generalized slow oozing, often seen in underlying coagulopathies, I will place a Jackson-Pratt or Penrose drain into the wound prior to repair and withdraw the drain after 48 hours.
8. Prescribe analgesics. This not only keeps the postoperative period more restful but also reduces anxiety, pain and elevated blood pressure. High blood pressure increases intraoperative and postoperative bleeding.
9. Place the wound at rest. Have patient avoid stooping, bending or lifting anything heavier than a 12oz. soda for 72 hours. Have them elevate the site and keep the area dry. Avoid any strenuous activity for 1 week. Emphasize that NSAIDs and aspirin are not to be taken for pain. Give written instructions.

Conclusion

Evidence continues to mount favoring blood thinner maintenance during cutaneous surgery. The risk of life-threatening thromboembolism associated with even brief cessation of blood thinners is significant. Unfortunately, primary care providers will remain unaware of the bleeding risks associated with cutaneous procedures such as Mohs excision and wound repair. The cutaneous surgeon should be aware of the various techniques and tools to reduce the risk of intraoperative and postoperative bleeding in patients taking blood thinners. Notwithstanding, bleeding complications carry far less morbidity and mortality than that of thromboembolism.