Are diagnostic errors a common medical mistake?

From the Editor…

According to an article written by Alexandra Sufferlin, a writer and producer for Time Healthland and published on April 24, 2013, diagnostic errors are the most common type of medical mistake. In fact, missed diagnoses out-ranked medication overdoses and surgical mistakes in causing the most patient harm. She writes:

When Dr. David Newman-Toker was a medical resident at a Boston hospital, he witnessed what he calls tragic cases in which otherwise healthy people suffered serious consequences from misdiagnoses that could have been prevented.

Newman-Toker, now an associate professor of neurology at the Johns Hopkins University School of Medicine, recalls an 18-year-old aspiring Olympic skater who fell on a ski slope and came to the hospital with weakness on one side of her body and a headache. She was told she had a migraine and was sent home. Six days later, she returned to the hospital after a stroke compromised the entire right side of her brain. He also remembers a hardworking janitorial immigrant in her 50s who came in with chest pain. She was seen multiple times at multiple hospitals and everyone missed that her chest pain was caused by compression from her spinal cord. By the time it was recognized, she was a paraplegic.

Not every visit to the hospital has a happy ending, and neither does every misdiagnosis lead to severe harm, but Newman-Toker’s personal experiences motivated him to improve medical misdiagnoses, which he says are not only common, but preventable in most cases. To gain more knowledge about the scope of medical diagnostic errors in the U.S., Newman-Toker and his colleagues reviewed 25 years of medical malpractice claim payouts and reported their findings in the journal BMJ Quality and Safety.

To make their estimates, the investigators studied medical malpractice payment data from the National Practitioner Data Bank, an electronic collection of all malpractice settlement payments made by practitioners in the U.S. since 1986. They found that diagnostic errors were the most common source of the payments, the most costly and the most dangerous when it came to patients’ health. Such errors, which included diagnoses that were incorrect or delayed — were most likely to result in death than other sources of malpractice suits such as surgical mistakes or medication overdoses.

The Diagnostic Iceberg

“People who study diagnostic errors have known for many years that diagnostic errors are the bottom of the iceberg. The tip of the iceberg is what we have been focusing on for the last decade, which is reducing medication errors and on-site surgeries. These are important problems, but they are not as big a problem in terms of their overall public health burden as diagnostic errors are,” says Newman-Toker.

The most common diagnostic errors were missed diagnoses, compared to those that were late or incorrect. “There are many missed diagnostic opportunities. That is, places where we know enough to get the right answer, but we don’t. Those missed opportunities, particularly the ones that result in harm, either death or disability, are the ones we are most worried about,” says Newman-Toker.

Addressing ways to improve on missed diagnoses, however, is challenging. The reason that medication mistakes and surgical errors have been confronted first is related to the fact that diagnoses are less objective, and more subjective. Determining whether a doctor’s assessment of what is making a patient sick is a combination of art and science, which makes diagnoses more uncertain than treatment, says Newman-Toker. For instance, doctors can give a patient a drug and figure out by their symptoms whether or not they are allergic, but when a patient comes in with dizziness or chest pain, the spectrum of conditions behind those symptoms can be overwhelming. “It’s a tougher task at the end of the day,” says Newman-Toker. “There is imperfect scientific knowledge, as in we just don’t always know what the diagnosis is, or we don’t have the technology to diagnose things on the first day they exist. We don’t have the technology to diagnose breast cancer when the first cancer cell appears.”

In the current era of health care reform, and in an effort to make services more efficient, doctors also walk a fine line between making a correct diagnosis without overusing diagnostic tests, which have resulted in major health care costs. A recent study showed that if doctors were shown the prices of the tests they order, they may become more cost efficient.

“We have to start measuring and tracking diagnostic error. We have to start applying research funds to improve research in this area to bolster what we are doing clinically. We have to make this more transparent than it has been and we need public reporting, we need required metrics, we need regulatory requirements and we need policy,” says Newman-Toker.

More research is also needed to provide better diagnostic tests that will improve their accuracy, especially for conditions with generalized symptoms. With so much focus on new treatments, research and innovation has shifted away from the importance of diagnosing conditions first. “Treatment starts with diagnosis. If you don’t get the diagnosis right, you can’t get the treatment right. And yet no one is working on it,” says Newman-Toker.

According to Dr. Hardeep Singh, a patient safety researcher at the Houston Veterans Affairs Health Services Research Center of Excellence and assistant professor of medicine at Baylor College of Medicine in Houston, more research on diagnosis errors that occur outside of  malpractice claims is also necessary. “We need to do more research to understand the contributory factors and we need to study and implement preventive strategies,” says Singh. He is currently working on refining electronic health records in order to improve follow-up and tracking of abnormal findings on test results.

Other health experts point to more systemic changes that also need to occur before significant progress in reducing misdiagnoses can happen. Ensuring that patients see their physicians regularly, and that they see the same doctor consistently so both parties are familiar with the patient’s medical history, could help. “The current fragmentation of our health care system makes these errors more likely,” says Dr. Richard Anderson, chairman and chief executive officer of The Doctors Company, the nation’s largest medical malpractice insurer and former chairman of the Department of Medicine at Scripps Memorial Hospital. “The commendable core of the patient safety movement is that we need to get away from the notion that a single doctor screwed up. The medical system needs to function much more reliably so that the health care system and the medical system work successfully to get patients through all the different interfaces.”

The Johns Hopkins researchers say hospitals should be required to track and report their misdiagnoses, and health care research dollars need to be invested in understanding how to avoid them. “I think that we, as a medical profession and as academic researchers, really have to provide the relevant information to policymakers to say: ‘look, this is money coming straight out of your pockets and your constituents are being harmed, and you need to take this seriously. Because we have ways to solve this problem,” says Newman-Toker.

As published in On the Road… June 2015

SG 02.04.03

 

What did we learn from the 2013 PRP Biopsy Poll?

During the summer of 2013, a total of 487 PRP patients were polled by email and given an opportunity to participate in a first-of-its-kind PRP Biopsy Poll. Remarkably, a total of 256 invitees (52.6%) shared their biopsy experiences and/or recollections.

✽    Dx with no biopsy ordered: 7.8%

✽    Dx with no contradictory biopsy: 45.3%

✽    Biopsy supported Dx: 23.4%

✽    Dx with no confirming biopsy: 23.4%

Everyone seems to agree that biopsies are a tool that reinforce the clinical observations of the dermatologist. If the dermatologist has seen PRP “in the flesh”, they consider it as a possible diagnosis sooner than a dermatologist who has absolutely no PRP experience.

I have spoken with dermatopathologists and they do look for “indicators”, but there doesn’t seem to be a “smoking gun” or a “Eureka” moment. I dug up my fifth Dermatopathology Report (Dr. Lydia Essary) and it said: “The findings were compared to the previous biopsy (CT12-204498) and the features in the current biopsy are a bit more characteristic and compatible with pityriasis rubra pilaris. Clinical correlation is recommended. Dr. Clay Cockerell has also reviewed this case and concurs with the diagnosis.”

The actual diagnosis was rendered by my second dermatologist who — earlier in his career — had been Chief Resident of Dermatology at University of Texas Southwestern in Dallas. Bottom line: it’s the clinical observation of a dermatologist who doesn’t get sucked down the rat hole of psoriasis, seborrheic dermatitis and other skin maladies that seem to mask PRP.

I wonder how many people with a psoriasis diagnosis who are NOT responding to the meds appropriate for psoriasis are, in fact, PRPers waiting to be found?

Like many PRP patients, my version of pityriasis rubra pilaris was misdiagnosed as seborrheic dermatitis and mistreated with escalating quantities of prednisone. After a week in the hospital and a fifth biopsy, the “official” PRP diagnosis was mercifully rendered.

“In retrospect,” Bill recalls, “my first dermatologist did not have PRP on her radar screen. The symptoms I presented were consistent with seborrheic dermatitis.”

A biopsy in September and two in October did not confirm PRP.  Moreover, a fourth biopsy performed at the Medical Center of Plano was also inconclusive. It was only when a new dermatologist ordered the fifth biopsy in late November and specifically included instructions for the lab to consider PRP that the results were classified as “a bit more characteristic and compatible with pityriasis rubra pilaris.”

The dermatopathology report included an important caveat: “Clinical correlation is recommended.” And that is the first answer to the question. We are told repeatedly that there is no “smoking gun” to be found in a skin biopsy. There is no “Gotcha” moment.

This reality begs another question: Are the characteristics of PRP really so elusive that they cannot be seen? Perhaps we need to interview 50 to 100 dermatopathologists as advocates of better PRP biopsies.

Unanswered questions

✽    How should a biopsy be performed to increase the likelihood of a timely PRP diagnosis.

✽    For what specific signs and.or indicators should a dermatopathologist be looking for?

Source: June 15, 2014 issue of On the Road….

 

SG 02.03.09

What are the possible results of a biopsy?

Editor’s Note: This is an unfinished article. Consider this to be a pre-DRAFT.

02.03.08  Biopsies— What are the possible results of a biopsy?

Completing the request form

The clinician should ensure the pathology request form includes basic patient information (including age and identification details), the site and type of biopsy, and time and date. Left and right are best written out in full to avoid mistakes

In addition to this, it is crucial for the pathologist to be provided with clinical information and a range of possible diagnoses. For best clinicopathological correlation clinical information should include a description of the duration, symptoms and a dermatologic description.

The sample pot should be labelled with patient identification details, the body site of the biopsy, time and date, and checked against the request form for consistency. When multiple biopsies are taken roman numbers are best used to match the request forms with their corresponding sample pots. DermNetNZ

1995-2013 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.

A skin biopsy is a procedure in which a sample of skin tissue is removed, processed, and examined under a microscope.

Results from a skin biopsy usually are available in 3 to 10 days.

Skin biopsy

Normal: The skin sample consists of normal skin tissue.

Abnormal: Noncancerous (benign) growths are seen. Benign growths do not contain cancer cells. Benign skin changes include moles, skin tags, warts, seborrheic keratoses, keloids, cherry angiomas, and benign skin tumors, such as neurofibromas or dermatofibromas.

Cancer cells such as basal cell cancer, squamous cell cancer, or melanoma are present.

Other diseases such as lupus, psoriasis, or vasculitis are present.

A bacterial or fungal infection is present.

Your doctor will talk with you about any abnormal results that may be related to your symptoms and past health. eMedicine

Results

A skin biopsy is a procedure in which a sample of skin tissue is removed, processed, and examined under a microscope.

Results from a skin biopsy usually are available in 3 to 10 days. WebMD.cancer

Skin biopsy

Normal: The skin sample consists of normal skin tissue.

Abnormal: Noncancerous (benign) growths are seen. Benign growths do not contain cancer cells. Benign skin changes include moles, skin tags, warts, seborrheic keratoses, keloids, cherry angiomas, and benign skin tumors, such as neurofibromas or dermatofibromas.

Cancercells such as basal cell cancer, squamous cell cancer, or melanoma are present.

Other diseases such as lupus, psoriasis, or vasculitis are present.

A bacterial or fungal infection is present.

Your doctor will talk with you about any abnormal results that may be related to your symptoms and past health. WebMD.cancer

What Affects the Test

© 1995-2013 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.

Taking medicines, such as anti-inflammatory medicines, those used for fungal infections (antifungal medicines), and corticosteroid skin creams, can interfere with your test or the accuracy of the results. eMedicine

Clinicopathological correlation

Skin diseases and conditions can at times be very difficult to diagnose accurately. In those cases the clinical and histopathological findings combined form a more complete picture to make a correct diagnosis. This is called the clinicopathological correlation. Many organisations hold regular multidisciplinary meetings (MDMs) at which clinical information, clinical photographs, and pathology slides are reviewed by a team of experts to determine the best diagnosis and treatment for the patient. DermNetNZ

What Affects the Test

Taking medicines, such as anti-inflammatory medicines, those used for fungal infections (antifungal medicines), and corticosteroid skin creams, can interfere with your test or the accuracy of the results. WebMD.cancer

What To Think About

• If the biopsy contains cancer cells, more surgery will be needed to remove the cancer completely.

• If the biopsy is done on your face, you may want to have it done by a doctor who specializes in surgical techniques that can minimize scarring, such as a plastic surgeon or dermatologist.

• Further testing may be needed if:

◦ A small biopsy does not contain enough cells to make an accurate diagnosis.

◦ Cells from the abnormal area weren’t included in the sample.

◦ The growth or skin rash changes after the first biopsy.  WebMD.cancer

SOURCES

http://www.dermnetnz.org/topics/skin-biopsy/

http://www.webmd.com/cancer/skin-biopsy#1

http://www.mayoclinic.org/tests-procedures/skin-biopsy/home/ovc-20196287

http://www.webmd.com/cancer/what-is-a-biopsy#1

• http://www.medicinenet.com/skin_biopsy/article.htm

What happens to the biopsy sample?

 

Editor’s Note: After four years of asking questions about PRP, the efforts of dermatopathologists remains an enigma. I have asked questions but the words I hear are like those spoken by adults in a Charlie Brown cartoon. All I hear is “Wah wah wah wah wah wah.” That’s when I feel like Snoopy.

The following post is just a first attempt at understanding what really goes on when a dermatopathologist looks at a slide through a microscope.

I will keep asking questions until Ginny Maxwell’s boys (Nathan and Joey) can make a PowerPoint presentation to their class in Lexington, South Carolina.

 Biopsies— What happens to the biopsy sample?

Most skin biopsies are placed in formalin in a small pot and are sent to the lab for paraffin fixation, processing and histopathological examination.
✽    If considering deep fungal infection or mycobacteria, the sample may be divided so that one part of the sample is sent in formalin for histopathology and the other is placed on a saline-soaked gauze swab for microbiology.
✽    Samples for direct immune fluorescence are placed in transport media, snap frozen in liquid nitrogen, or sent “fresh” (eg placed on a moistened gauze swab in a sterile empty pot).

Editor’s Note: Why am I thinking about Winnie the Pooh and his honey pot. The fact is, I don’t have a clue what a biopsy pot looks like.

What affects the test

✽    Taking medicines, such as anti-inflammatory medicines, those used for fungal infections (antifungal medicines), and corticosteroid skin creams, can interfere with your test or the accuracy of the results.

Obtaining the results of the biopsy

✽    It usually takes about one or two weeks to obtain the result from the pathology laboratory, but can sometimes take longer if special stains or second opinions are required.
✽    The pathologist describes what is observed under light microscopy in several sections of the biopsy sample, and either makes a diagnosis or assists in differentiating between the suggested range of clinical diagnoses.

Editor’s Note: Here is where many PRP patients (active and in remission) and their caregivers start bouncing around like Tigger. Remember — we have an über-rare skin malady. Biopsies generally exclude the more common skin disorders.

Based on the first biopsy we know it is NOT psoriasis. The second biopsy excludes eczema. And the third biopsy eliminates seborrheic dermatitises a contender. By now the patient is “in full bloom, head to toe with islands of sparring. The dermatologist remembers a grand rounds in medical school and thinks “pityriasis rubra something”.

The plot thickens. The dermatologist writes the order for the dermatopathologist with SPECIFIC instructions to consider pityriasis rubra pilaris. The dermatopathologist finds whatever SIGN there is that only dermatopathologists can see and writes a finding. It is NEVER a statement like “You can take a diagnosis of pityriasis rubra pilaris to the bank!” Rather, the wording will be reflective, “The biopsy supports the clinical observations of the dermatologist.”

At least now the dermatologist can confirm the diagnosis to the PRP patient and caregiver and a proper treatment plan may be initiated.

SOURCES

✽    http://www.dermnetnz.org/topics/skin-biopsy/
✽    http://www.webmd.com/cancer/skin-biopsy#1
✽    http://www.mayoclinic.org/tests-procedures/skin-biopsy/home/ovc-20196287
✽    http://www.webmd.com/cancer/what-is-a-biopsy#1
✽    http://www.medicinenet.com/skin_biopsy/article.htm

SG 02.03.07

How is a biopsy performed?

Editor’s Note: A skin biopsy is routinely performed in the dermatologist’s office.

Preparation

✽    Tell your doctor if you have any allergies to medications, and especially if you have had any reactions to local anesthetics, such as lidocaine or novocaine, or to iodine cleaning solutions, such as Betadine.44.

✽    Inform your doctor if you are taking any medications, including over-the-counter drugs, street drugs, or herbal or nutritional supplements.

✽    Tell your doctor if you have any bleeding problems or if you are pregnant.

✽    You may be asked to change into a gown or remove an article of clothing so that the area of suspect skin can be more easily seen and removed.

How biopsy is performed

✽    It is crucial that the site of a biopsy is chosen carefully, or the pathological diagnosis could be incorrect or misleading.

✽    The site of the skin biopsy may be cleaned with an iodine-type solution, with alcohol, or with a sterile soap solution.

✽    A marker may be used to outline the edges of the skin sample.

✽    For some biopsies, a surgical drape is used to cover the area around the biopsy and the doctor will wear a mask, gown, and gloves.

✽    Several different methods may be used to obtain a skin sample, depending on the size and location of the skin lesion.

✽    The skin sample is placed in a solution, such as formaldehyde, or in a sterile container if infection is suspected. In each of these procedures, the tissue is then examined under a microscope.

✽    After the skin has been cleaned, sterile towels are placed around the area.

✽    Do not touch this area once it has been cleaned and prepared.

✽    A local anesthetic, usually lidocaine, is injected into the skin to make it numb. You will feel a brief prick and stinging sensation as the medicine is injected. After the skin is numb, your doctor performs the biopsy.

After the Skin Biopsy Procedure

✽    Your doctor will put a bandage over your biopsy site. Keep this bandage dry. You may be advised to wash the wound, apply antibacterial ointment or petrolatum (Vaseline) and change the bandage daily.

✽    If you have stitches, you need to keep the area clean and dry. Follow instructions regarding when and how to wash the wound. Stitches on the face are removed in 5-8 days. Stitches placed elsewhere on the body are removed in 7-14 days. Adhesive strips are left in place for 10-21 days.

✽    If you have pain at the biopsy site, talk with your doctor about medication to relieve it. In most cases, discomfort is minimal and requires nothing more than an over-the-counter pain medication. 

✽    Your doctor will give you specific instructions on how to care for your biopsy site. Keep the biopsy site clean and dry until it heals completely.

✽    Your stitches will be taken out 3 to 14 days after the biopsy, depending on the biopsy site. Adhesive bandages should remain in place until they fall off. This usually takes from 7 to 14 days.

✽    The biopsy site may be sore or bleed slightly for several days. Ask your doctor how much bleeding or other drainage is expected. Call your doctor immediately if you have: (1) excessive bleeding or drainage through the bandage, (2) increased tenderness, pain, redness, or swelling at the biopsy site or (3) a  fever.

Next Steps after Skin Biopsy

✽    Your doctor needs to see you again to remove the stitches and to give you the results of the pathology report. If no stitches are placed, he may ask you to get in touch by phone so he or she can discuss the results for you.

Sending the sample to a dermatopathologist

✽    The clinician should ensure that the pathology request form includes basic patient information (including age and identification details), the site and type of biopsy, and time and date. “Left” and “right” are best written out in full to avoid mistakes

✽    It is crucial for the pathologist to be provided with clinical information and a range of possible diagnoses. Clinical information should include a description of the duration, symptoms and a dermatologic description.

Editor’s Note: This is where it is important for a dermatologist who suspects pityriasis rubra pilaris to share that information with the dermatopathologist.

✽    The sample pot should be labelled with patient identification details, the body site of the biopsy, time and date, and checked against the request form for consistency. When multiple biopsies are taken roman numbers are best used to match the request forms with their corresponding sample pots.

✽    The tissue that is removed is sent to the laboratory for analysis by a dermatopathologist.

Sources used to prepare this article

✽    http://www.dermnetnz.org/topics/skin-biopsy/
✽    http://www.webmd.com/cancer/skin-biopsy#1
✽    http://www.mayoclinic.org/tests-procedures/skin-biopsy/home/ovc-20196287
✽    http://www.webmd.com/cancer/what-is-a-biopsy#1
✽    http://www.medicinenet.com/skin_biopsy/article.htm

02.03.06

What are the risks associated with a skin biopsy?

An accurate diagnosis of pityriasis rubra pilaris requires a proper skin biopsy.

✽   A skin biopsy is the most common and also the most essential procedure performed by a dermatologist in day-to-day practice. It is safe and easy, with not only diagnostic purpose, but also has significant therapeutic value. It is performed as an office procedure both on an outpatient and inpatient basis. Though it is one of the simplest procedures to perform, occasionally we come across complications related to skin biopsy.”

✽  A skin biopsy is the most important diagnostic procedure for a dermatologist. However, awareness about the possible complications that can arise due to this small procedure helps in better outcome for the patients and less hassles for the dermatologist.

✽  A skin biopsy is usually straightforward and complications are uncommon. As a general rule, the larger the skin sample removed, the higher the chance of complications.

✽  You should discuss with your doctor the following potential risks and complications of the biopsy procedure. You may need to sign a consent form before the procedure is performed.

✽  In order to prevent or reduce complications it is necessary for your dermatologist to conduct a physical examination and take a complete history before performing a skin biopsy. The detailed history should specifically  identify medications that can cause prolonged bleeding, increase risk of infection or delay healing.

Possible risks include the following:

PAIN

✽  Mild pain is usually experienced during skin biopsy. Severity of pain may vary according to the site where biopsy is being performed.

✽  You will feel brief stinging pain when the local anesthetic is injected. You should not feel any pain when the skin sample is removed.

✽  Occasionally pain can be more severe if there is:

✽  Inadequate local anesthetic injection.

✽  Short time gap between injecting the anesthesia and performing the procedure.

✽  Wrong site of application of anesthesia.

✽  Inadequate depth of applying anesthesia.

BLEEDING

✽  Although unlikely, there is a slight risk of  of persistent bleeding.

✽  Bleeding can occur in anyone, but can be particularly troublesome in those with a bleeding tendency, or taking blood-thinning medications such as warfarin or aspirin.

SCARRING

✽  If you usually form scars after skin injuries or surgery, you could develop a scar at the biopsy site.

✽  Smoking and some chronic medical conditions such as diabetes affect the healing ability of the skin.

✽  It is usual for a biopsy site to form a significant permanent scar. Some body sites such as the centre of the chest are prone to develop excessive scars. This is also more common in Afro-Caribbean skin types.

INFECTION

✽  There is a slight risk of Infection.

✽  Bacterial wound infection affects about 1–5% of excisional biopsies. It is however extremely uncommon in small punch, shave or incisional biopsies.

✽  Ulcerated or crusted skin lesions, site of biopsy, patient characteristics such as diabetes, older age, or use of immunosuppressive medicines may contribute to increased risk of infection.

NERVE INJURY

✽  The blade may cut a superficial sensory nerve causing pain or numbness. This is most likely to occur where the skin is thin, for example on the face or back of hand. Risk of motor nerve impairment is extremely rare, but can occur during skin cancer surgery in facial danger zones.

ANESTHETIC PROBLEMS

✽  Allergies to local anesthetics are a possibility but are also extremely rare.

Sources used in preparing this post

✽  Kumar Abhishek and Niti Khunger; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4728909/

✽  http://www.dermnetnz.org/topics/skin-biopsy/

✽  http://www.webmd.com/cancer/what-is-a-biopsy#1

✽  http://www.medicinenet.com/skin_biopsy/article.htm

Have you experienced any complications related to skin biopsies?

02.03.05

What should the patient know about biopsies?

No special preparation is needed before having a skin biopsy.

Before a skin biopsy, Talk to your doctor about any concerns you have regarding the need for the test, its risk, how it will be done, or what the results will mean.

Tell your doctor if you:

✽  Are taking any medicines, particularly anti-inflammatory medicines such as prednisone. Anti-inflammatory medicines may change the way your biopsy looks under the microscope.

✽  Are allergic to any medicines.

✽  Have had any bleeding problems or are taking blood-thinning medicines, such as aspirin or warfarin (Coumadin).

✽  Are or might be pregnant.

You may be asked to sign a consent form that says you understand the risks of the test and agree to have it done.

How It Is Done

✽  Usually the place where the biopsy will be taken is cleaned with an alcohol wipe.

✽  A marker may be used to outline the edges of the skin sample.

✽  For some biopsies, a surgical drape is used to cover the area around the biopsy and the doctor will wear a mask, gown, and gloves.

✽  Several different methods may be used to obtain a skin sample, depending on the size and location of the skin lesion.

✽  The skin sample is placed in a solution, such as formaldehyde, or in a sterile container if infection is suspected. In each of these procedures, the tissue is then examined under a microscope.

Choosing the type of and site for a biopsy

✽  It is crucial that the site of a biopsy is chosen carefully, or the pathological diagnosis could be incorrect or misleading. Here are a few guidelines to help find the best site, some general advice and pitfalls to avoid, depending on the type of skin lesion.

Obtaining the results of the biopsy

✽  It usually takes about one or two weeks to obtain the result from the pathology laboratory, but can sometimes take longer if special stains or second opinions are required.

✽  The pathologist describes what is observed under light microscopy in several sections of the biopsy sample, and either makes a diagnosis or assists in differentiating between the suggested range of clinical diagnoses.

SOURCES

✽  http://www.dermnetnz.org/topics/skin-biopsy/
✽  http://www.webmd.com/cancer/skin-biopsy#1
✽  http://www.mayoclinic.org/tests-procedures/skin-biopsy/home/ovc-20196287
✽  http://www.webmd.com/cancer/what-is-a-biopsy#1
✽  http://www.medicinenet.com/skin_biopsy/article.htm
✽  http://www.mayoclinic.org/tests-procedures/skin-biopsy/details/risks/cmc-20196351

SG 02.03.04

What are the types of skin biopsies

There are three main types of skin biopsies: shave, punch and excision. According to PRP patients and caregivers, shave biopsies and punch biopsies are the types used as a PRP diagnostic tool .

Shave biopsy

✽    A doctor uses a tool similar to a razor to remove a small section of the top layers of skin (epidermis and a portion of the dermis).

✽    No stitches are required. The wound forms a scab that should heal in 1–3 weeks.

✽    As a shave biopsy does not include the full thickness of the skin, the drawback of such a biopsy is that it may be difficult for a pathologist to rule out or identify invasive disease.

✽    After a local anesthetic is injected, a surgical knife (scalpel) is used to shave off the growth . Stitches are not needed.

✽    Any bleeding can usually be controlled with a chemical that stops bleeding and by applying pressure.

✽    The biopsy site is then covered with a bandage or sterile dressing.

Punch biopsy

✽    The punch biopsy is generally the most useful type of biopsy. It is quick to perform, convenient, and only produces a small wound. It creates a full thickness sample of skin that allows the pathologist to get a good overview of the epidermis, dermis, and most of the time, the subcutis also.

✽    In a punch biopsy,  a cookie cutter-like, circular tool to remove a small section of skin including deeper layers

✽    A disposable skin biopsy punch is used, which has a round stainless steel blade ranging from 2–6 mm in diameter. The 3 and 4 mm punches are the most common sizes used.

✽    The clinician holds the instrument perpendicular to the anaesthetized skin and rotates it to pierce the skin. Using a forceps and scissors the skin sample is subsequently removed.

✽    After a local anesthetic is injected, a small, sharp tool that looks like a cookie cutter (punch) is placed over the lesion, pushed down, and slowly rotated to remove a circular piece of skin .

✽    The skin sample is lifted up with a tool called a forceps or a needle and is cut from the tissue below.

✽    A suture may be used to close a punch biopsy wound or help control bleeding if necessary.  However, if the wound is small, it may heal adequately without it. Stitches may not be needed for a small skin sample. If a large skin sample is taken, one or two stitches may be needed. Pressure is applied to the site until the bleeding stops.

✽    The wound is then covered with a bandage or sterile dressing.

Excision biopsy

✽    Excision biopsy refers to complete removal of a skin lesion, such as a skin cancer in which a margin of surrounding skin is taken to improve chances of complete removal. Smaller lesions are most often removed using a scalpel blade as an ellipse, with primary closure using sutures. Larger excisions may be repaired using a skin flap (moving adjacent skin to cover the wound) or graft (skin taken from another site to patch the wound).

✽   This type of biopsy may be useful to provide a better overview for the pathologist, which can improve diagnostic accuracy. It can also be useful when deeper layers or tissue are believed to be involved in the disease process (eg, subcutaneous fat or medium-sized blood vessels).

✽    A doctor uses a small knife (scalpel) to remove an entire lump or an area of abnormal skin, including a portion of normal skin down to or through the fatty layer of skin

✽    After a local anesthetic is injected, the entire lesion is removed with a scalpel. Stitches are used to close the wound. Pressure is applied to the site until the bleeding stops. The wound is then covered with a bandage or sterile dressing. If the excision is large, a skin graft may be needed.

SOURCES

✽    http://www.dermnetnz.org/topics/skin-biopsy/
✽    http://www.webmd.com/cancer/skin-biopsy#1
✽    http://www.mayoclinic.org/tests-procedures/skin-biopsy/home/ovc-20196287
✽    http://www.webmd.com/cancer/what-is-a-biopsy#1
✽    http://www.medicinenet.com/skin_biopsy/article.htm

02.03.03