What is Biopsy of Nail Unit: Overview, Benefits, and Expected Results

Definition and Overview

A biopsy of nail unit is performed to help diagnose nail disorders or to examine a suspected cyst, wart, or tumour. It involves taking a small piece of tissue from any of the many different components of the nail, such as the nail plate, nail bed, hyponychium, proximal nail fold, or the lateral nail fold. The results of the biopsy are used to determine the most appropriate treatment plan for the condition.

Who Should Undergo and Expected Results

The procedure is for patients who are suspected of having a nail disorder due to the presence of some symptoms, such as:

• Recurrent fungal nail infections
• Nail plate deformity
• Pain
• Longitudinal pigmented streaks on the nail surface

A biopsy can help diagnose the following problems:

• Malignant periungual and subungual tumours
• Benign tumours
• Psoriatic nail
• Mycotic nail
• Onycholysis
• Lichen planus

Although it is not considered as the primary diagnostic tool for nail disorders, the procedure is sometimes necessary when the results of routine diagnostic procedures are inconclusive.

How is the Procedure Performed?

There are many types of nail biopsy depending on which part of the nail is involved. Determining the most effective and most appropriate biopsy method to use is important to ensure that the procedure is both safe and beneficial for the patient. Local anaesthesia is typically used especially if the procedure is expected to be invasive. The anaesthetics are applied through an injection or a digital block, in which the anaesthesia is injected through the web spaces along the side of the toe or finger.

The different types of biopsies performed on the various components of the nail include:

• Nail plate biopsy – This procedure is typically performed to diagnose mycotic nail dystrophies. It involves taking a piece of the distal plate and a portion of the hyponychium underneath it using scissors or a scalpel. If the disease is suspected to have spread beyond the distal nail plate, a trephine punch may be used to gain access to the periosteum. The punch, which is usually 3 to 4 mm in size, is then withdrawn along with the tissue sample.

• Nail bed biopsy – This is commonly performed to confirm a suspected tumour or lesion in the nail bed. It is carried out through a standard punch biopsy, which leaves only a small wound that does not require sutures. In some cases, a nail bed sample is taken along with a nail plate sample in a procedure called a 2-punch technique. In most cases, patients heal well and experience minimal scarring following the procedure.

• Nail matrix biopsy – This is performed to diagnose tumours that form on the nail matrix or to determine the cause of nail malformations and dystrophies. It is also helpful in diagnosing melanonychia striata or malignancy. The procedure can be performed by removing the whole lesion using a 3mm punch biopsy or through a transverse elliptical wedge excision.

If the tissue taken is bigger than 2 mm, the wound is closed with sutures. The tissue sample is then placed in a periodic acid-Schiff or Gomori methenamine-silver stain.

Possible Risks and Complications

A biopsy of the nail unit is associated with some complications, such as:

• Bleeding
• Infection
• Scarring
• Misdiagnosis
• Incomplete tumour removal
• Splitting of the nail

To help minimise complications, only the smallest amount of tissue possible is taken during a nail biopsy to reduce the risk of affecting the surrounding healthy tissue. The larger the punch biopsy used, the greater the risk of complications. Most doctors also prefer to perform a biopsy of the nail bed to avoid affecting the nail matrix.

The above complications can be avoided or minimised by taking only longitudinal samples of the nail bed, most preferably at the lateral margin of the nail, and transverse samples of the nail matrix.

References:

• Rosendahl C. “Nail matrix biopsy.” 2013. DermNet New Zealand. http://www.dermnetnz.org/topics/nail-matrix-biopsy/

• Rich P, Jefferson JA. “Nail biopsy: Indications and techniques.” http://www.uptodate.com/contents/nail-biopsy-indications-and-techniques

• Onumah N. “Nail surgery workup.” http://emedicine.medscape.com/article/1126725-workup

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**What is Biopsy of Nail‌ Unit: Overview,⁤ Benefits, and Expected Results**



**Introduction**



A nail biopsy is a ‌medical‍ procedure that involves removing a small sample of tissue from the nail unit for examination under a microscope. It is typically performed to diagnose or rule out various conditions affecting the nails, such as infections, autoimmune disorders, ⁤and tumors.



**Overview ‌of Nail Biopsy**



* The biopsy is typically performed under local anesthesia.

* A small incision is made in the proximal or lateral nail⁤ fold, and a sample of tissue is removed using a punch biopsy tool or scalpel.

* The tissue ⁤sample is then sent to a laboratory for analysis.

* The procedure usually takes less​ than 30 minutes.

* Patients may experience some discomfort or pain during the biopsy, but it is generally well-tolerated.



**Benefits of Nail Biopsy**



* **Accurate Diagnosis:** A biopsy allows for the‌ precise identification of the cause of the nail abnormality.

* **Exclusion of Malignancy:** It can help ‍rule out or confirm​ nail tumors, which ‍is ‍crucial for timely management.

* **Assessment of Nail Matrix:** It can provide information about conditions affecting the nail matrix, which is responsible for nail growth.

* **Guidance for Treatment:** The results of the biopsy can guide appropriate treatment decisions.



**Expected Results**



The ‌results of the biopsy ‍will depend on the underlying condition. The pathologist analyzing the tissue sample will look for abnormal cells, microorganisms, or ‍other findings that may⁣ provide⁢ diagnostic ​clues. Possible outcomes include:



* **Normal Results:** The tissue‌ appears normal, and no underlying pathology is identified.

* **Infectious Nail Disease:** Fungal or bacterial infections may be detected.

* **Autoimmune Conditions:**‌ Psoriasis or lichen planus‌ can be diagnosed based on specific tissue changes.

* **Nail Tumors:** Benign or malignant nail ​tumors can be identified and classified.

* **Other Conditions:** Certain genetic disorders or metabolic ⁢abnormalities may be detected.



**Follow-Up**



After the biopsy, patients will⁣ typically have a follow-up appointment to review the results and discuss further management ⁢options. Depending on the diagnosis, they may be prescribed topical or systemic medications, undergo surgical excision, or ‍receive other appropriate treatments. Regular monitoring of the nail unit may be recommended to assess treatment response and prevent recurrences.



**Additional Information**



* Nail biopsy ‌is generally a safe procedure with minimal risks.

* It ⁢is important to inform the doctor about any allergies or medical conditions before undergoing the biopsy.

* Patients should keep the incision⁢ site clean and dry to prevent infection.

* Most patients can resume their normal activities within a few days of the biopsy.