Common Nail Procedures

Common Nail Procedures

CHAPTER 15 Common Nail Procedures ALEXANDER DAOUD, MD  •  MARTIN ZAIAC, MD KEY FEATURES • Disorders involving the nail unit are common in both th...

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• Disorders involving the nail unit are common in both the primary care and the dermatology clinic. Providers should be aware of the range of procedures available in the diagnosis and management of various pathologies. • By virtue of the nail unit’s unique anatomy, procedural complexity can range from nail clipping to microsurgery. Accordingly, consultation with a dermatologist or hand surgeon is warranted whenever questions of technical difficulty arise. • In this chapter, we review common nail procedures within the armamentarium of the general dermatologist, including indications, techniques, and special considerations for each.

INTRODUCTION The nail unit, which comprises the nail plate, the underlying nail bed, the nail matrix, and the lateral nail folds, is a unique structure in human anatomy. Functionally, nails provide the distal digits with an affixed focus on counterpressure, thus enhancing fine touch and pressure discrimination for the palmar aspects of the fingertips. They also serve as important components of grasp, especially in fine, coordinated grasp of small objects.1,2 The nail unit also serves as a barometer of systemic health: changes in the nail bed and nail plate can clue physicians in to disease etiologies ranging from infectious to autoimmune and more. Socially, nail augmentation is one of the commonest cosmetic undertakings: nail painting is practiced worldwide, and in the United States there were over 129,000 licensed nail salons in 2015.3 Together, these factors stress the importance of nail health in daily life. When indicated, clinicians may need to perform procedures on the nail unit to diagnose or treat disease. Whenever possible, the overarching goal is to preserve or restore both function and cosmetic appearance. In this chapter, we review several of the most common procedures conducted on the nail unit. While more technical approaches will be discussed elsewhere in this text, many of the techniques described are essential components in a dermatologist’s procedural oeuvre. 

INSTRUMENTATION, ANESTHESIA, AND GENERAL CONSIDERATIONS While the surgical implements used will vary on a caseby-case basis, there are several items that will allow clinicians to conduct most basic nail procedures. These

include fine (Iris) scissors, forceps, skin hooks, nail splitters, nail elevators, and scalpels of varying blade sizes. To tourniquet bleeding in the hand, a common practice is to have the patient wear a tight-fitting disposable glove, then cut the distal tip off for the finger undergoing the procedure. By rolling the cut digit down to the base of the proximal phalanx, one can reliably occlude flow through the dorsal and volar digital arteries. An exsanguinating tourniquet may also prove helpful in promoting venous outflow before proximal tourniquet placement. When operating on the toenails, a disposable tourniquet or tied Penrose drain may prove useful.2 In nail surgery, the anesthetic mode of choice is nerve block by 1% lidocaine. Historically, combinations of lidocaine and epinephrine have been widely advocated against, given the possible risk of inducing digital necrosis, although some studies have not demonstrated a measurable increased risk when these combinations were used. In a systematic review comprising four randomized control trials, insufficient statistical significance was reached to advocate either for or against the safe use of lidocaine and epinephrine in digital nerve blocks.4 Nevertheless, as microvascular disease caused by diabetes or vascular disorders can result in patients presenting with preexisting digital vessel compromise, injection with 1% lidocaine, coupled with adequate tourniquet application, can achieve both successful anesthesia and bleeding control. The two most commonly used approaches to digital nerve block are the proximal and distal nerve blocks. In a proximal (or traditional) digital nerve block, a 25to 30-gauge needle is introduced into the dorsolateral 139


Nail Disorders

FIG. 15.1  Distal (wing) nerve block. A 30-gauge needle

is advanced distally toward the junction of the proximal and lateral nail folds, where introduction of a small bolus of local anesthetic results in near-instantaneous anesthesia. This approach also allows for improved hemostasis, as evidenced by the tissue blanching seen earlier. (Courtesy of Martin Zaiac, MD, Miami, FL; with permission.)

block, 1% lidocaine is introduced into the flexor tendon sheath, using the distal transverse palmar crease as a landmark for injection. Although a 1- to 2-cc bolus can reliably anesthetize the length of the digit, pain associated with injection of the palm may limit the use of this approach.6 A unique approach is taken in anesthesia of the great toe. Unlike the other digits, there are additional bundles of nerves that travel along the dorsum of the great toe, near the midline of the digit. The three-sided toe block addresses this nerve bundle by first using a proximal digital nerve block to anesthetize the lateral and medial sides of the toe; however, before withdrawing the needle, the operator turns the needle perpendicularly across the base of the toe and advances across the toe dorsum toward the midline of the digit, introducing an extra dose of anesthetic.7 

PROCEDURES ON THE NAIL PLATE aspect of the proximal phalanx, in close proximity to the web space. The needle is advanced toward the palmar/plantar surface until it makes contact with the phalanx, at which point it is retracted approximately 1–2 mm before a bolus of 1–2 mL of anesthetic is introduced. This procedure is then repeated on the contralateral side of the digit. Benefits of a proximal approach include reliable, complete anesthesia of the digit with relatively minimal pain; however, the time to full anesthetic effect is usually 5–12 min.2,5 This is in comparison with the wing (distal) nerve block, which achieves a near immediate anesthetic effect by injecting a small bolus of anesthesia directly into the proximal nail fold, followed by forwardly advancing injection toward the tip of the digit after entry at the base of the proximal and lateral nail folds. The approach requires use of a far smaller bolus of anesthetic (along the lines of tenths of an mL), and it helps promote hemostasis by virtue of the anesthetic load compressing distal capillaries. However, as there are more nerve endings at the tips of the fingers, patients report that this approach is generally more painful than the traditional approach. Furthermore, wing blocks are strictly contraindicated whenever there is question of a bacterial infection, such as paronychia or felon, affecting the distal digit2,5 (Fig. 15.1). In the hand, one may choose to use a transthecal block. This approach uses the channel created by the digit’s flexor tendon sheath to evenly distribute anesthetic. Benefits of this approach include “one injection” anesthesia, as only one needle puncture is required to anesthetize the entirety of the digit. In a transthecal

The hard, keratinized nail plate may undergo changes in color, texture, or growth secondary to a number of disease processes. Three of the most common procedures conducted on the nail plate are discussed below.

Evaluation of Onychomycosis Onychomycosis is the most common infection of the nail, with estimates that fungal infections account for nearly 50% of all nail diseases and with prevalence in some populations ranging from 10% to 20% of all adults.8 Evaluation for the presence of hyphae via microscopy remains the gold standard in diagnosis owing to procedural simplicity with minimal items required. Nail clippers are used to remove the distal portion of the nail plate, exposing accumulated subungual debris. A curette or sterile 15-blade scalpel is then used to collect the debris onto a glass microscope slide, at which point 10%–20% of KOH solution (with or without dimethylsulfoxide) is applied to the collected specimen. Appearance of hyphae on microscopy is diagnostic for onychomycosis, although some studies report a false-negative rate of nearly 30%. 

Trephination for Subungual Hematoma Subungual hematomas, which typically not only result after acute crush injury but can also be seen in cases of repetitive trauma (e.g., long distance runners), are caused by rupture of vessels within the nail bed. Encasement of the bleed by the nail plate results in visible collection of a hematoma that is associated with mild to

CHAPTER 15  Common Nail Procedures severe throbbing pain. Trephination, or introduction of a surgically created hole, through the nail plate can provide immediate pain relief, as well as reduce the resultant nail discoloration. Despite the frequency with which subungual hematomas occur, there still exists controversy regarding when trephination versus exploration of the nail bed for lacerations is indicated. Historically, hematomas greater than 50% of the total nail surface were guided to undergo repair via suturing of a nail bed laceration; this recommendation was derived from a study of 47 patients that identified repairable lacerations (>3 mm) in 60% of individuals with a hematoma spanning more than 50% of the nail plate.9 However, multiple subsequent studies have contested this conclusion by demonstrating appropriate rates of resolution when trephination of large hematomas was chosen over laceration repair. These authors also demonstrated increased rates of infection and resultant nail deformity in patients undergoing nail avulsion with laceration repair.10 Regardless, in instances where the hematoma spans greater than 50% of the nail plate, it is prudent to obtain an X-ray of the digit to rule out any concomitant phalangeal fracture. If phalangeal fracture is present, then exposure of the nail bed may be necessary to repair a laceration. Furthermore, in instances where the nail matrix is involved in a region of fracture, nail avulsion with repair of the laceration is indicated to prevent delay of fracture union or formation of an intraosseous inclusion cyst.11 If the hematoma is less than 24 h old and comprises less than 25%–50% of the surface of the nail plate, then trephination with electrocautery or nail boring may be safely used. In resource-limited areas, a common approach has involved heating of a paper clip; however, as contemporary paper clips comprise aluminum alloys that may not reach a temperature adequate for penetrating the nail plate, this approach is advised against. The clinician applies gentle pressure with the device of choice to the center of the hematoma, advancing until blood is liberated from the nail. Gentle pressure against the nail plate will then liberate the majority of the collected blood, resulting in near-immediate pain relief for the patient. If boring with a physical device is selected, use of an 18-gauge needle should produce a hole wide enough to prevent clotting over, which could result in reaccumulation of the blood. To prevent damage to the nail matrix, which could result in permanent nail splitting, trephination over the lunula is never indicated. Following the procedure, patients should be advised that oozing of blood from the trephination site is common for up to 24–48 h (Fig. 15.2). 


FIG. 15.2  Trephination of a subungual hemorrhage, left

great toe. Using an 18-gauge needle, a provider bores through the nail plate to liberate a subungual hemorrhage. Upon reaching the potential space between the nail plate and nail bed, blood fills the hollow needle, often leading to immediate relief of discomfort. (Courtesy of Martin Zaiac, MD, Miami, FL; with permission.)

Nail Avulsion Partial or complete avulsion of the nail may be required to treat or diagnose a number of different nail unit pathologies; these include repair of nail bed lacerations; biopsy of nail bed or nail matrix lesions; excision of tumors; and treatment of recurrent onychocryptosis, onychomycosis refractory to antifungal regimens, or pincer nails. Furthermore, nail avulsion may precede total matricectomy, an approach that may be useful in the management of congenital nail deformities, onychogryphosis, or severe recurrent nail infections.12 Regardless of approach, avulsion results in separation of the nail plate from its two primary points of attachment: the nail bed and the proximal nail fold. In the distal approach to complete nail avulsion, the practitioner introduces a nail elevator at the hyponychium, in-between the nail plate and nail bed. The elevator is advanced toward the proximal nail fold until the proximal nail groove is reached; this is indicated by a sudden decrease in the force required to advance the septum elevator. The same longitudinal approach is taken until the bulk of the nail plate is free from the nail bed; then, the plate is released from the lateral nail folds and a hemostat is used to pull the plate free.


Nail Disorders

The proximal approach to nail avulsion requires a practitioner to first free the proximal nail fold, then reflect this tissue proximally to reveal the origin of the nail plate. This approach is technically more difficult, although some report that it may offer clinical benefit in cases where severe nail dystrophy hinders a distal approach, as well as in cases of severe paronychia refractory to antibiotics.2,12 When a lesion is limited in its extent of nail unit involvement, clinicians may elect to perform partial nail avulsion. This approach offers the dual benefit of maintaining the functional capacities of the nail plate, such as counterpressure for the digital pulp, while also protecting a majority of unaffected nail bed. Similar to the distal avulsion technique, a Freer septum elevator is introduced at the hyponychium, dissecting toward the proximal nail groove. However, once the portion of plate covering the area of interest is liberated from the nail bed, the clinician then dissects the closest lateral nail fold and uses either a nail splitter or a rongeur to clip the affected portion of the nail plate. Such lateral plate avulsion may prove beneficial in the management of ingrown or pincer nails.13 In cases where plate avulsion was conducted to repair a laceration or conduct a biopsy, clinicians may replace the native plate to protect the exposed nail bed. After a soak in Betadine solution, the nail plate is returned to the digit and affixed using nonabsorbent monofilament thread. The nail is fixed at three points: the distal nail margin to the fingertip and the proximalmost portions of the lateral nail folds; for this, a figureof-eight tie may be used. The nail should be examined in 5–7 days of accumulation of a hematoma or seroma, which can be prevented by trephination of the plate before implantation. Suture material can be safely removed after 14–21 days, with the native plate adhering to the nail bed for 1–3 months, as it is displaced by new nail growth.13,14 If fixation of the plate is not an option, then petroleum jelly should be applied to the exposed area of the nail bed and then covered with nonadherent dressing. If circumferential bandaging is used, the entire digit should be loosely wrapped with rolled gauze. 

PROCEDURES ON THE NAIL BED After release of the nail plate, a number of procedures may be performed on the nail bed. Most commonly, these include repair of lacerations, excision of tumors or growths, and punch biopsy of suspicious lesions.

Repair of Nail Bed Lacerations As mentioned previously, repair of lacerations to the nail bed remains a somewhat controversial mode of treatment, with several small studies demonstrating equal rates of resolution and lower rates of postoperative complication when providers performed nail plate trephination. Nevertheless, laceration repair remains an appropriate mode of therapy when hematoma comprises more than 50% of the nail plate, as well as when the hematoma is accompanied by phalangeal fracture (as repairable lacerations may be seen in up to 95% of patients in this latter group).11,14 After removal of the nail plate, the nail bed is irrigated with sterile saline and the laceration is closed with 6-0 absorbable suture thread. To decrease the risk of permanent nail growth deformities, splinting of the eponychial fold with the native nail or a small piece of nonadherent gauze is recommended. By placing a barrier underneath the eponychial fold, there is a lower risk of damage to the nail germinal matrix, which is associated with complications such as split nail deformity. Lacerations may also be effectively closed with polymerized tissue adhesives. A 2008 randomized control trial comparing the efficacy of 2-octocyanylacrylate (Dermabond) with that of standard suture repair demonstrated no statistical differences in physicianor patient-perceived cosmesis, postoperative pain, or functional ability between patients whose nail bed lacerations were repaired with Dermabond over suturing. Furthermore, use of the liquid tissue adhesive was associated with an average procedural time of 9.5 min, whereas suturing required an average procedural time of 27.8 min .15 Complex lacerations, such as those involving the nail matrix, will be discussed elsewhere in this text. 

Biopsy and Excision of Local Tumors Nail biopsies may serve both diagnostic and therapeutic benefits, as tissue sampling may confirm the presence of pathology while also eradicating disease and resolving symptomatology (pain, decreased cosmesis, etc.). When the lesion is contained within the nail bed (no longitudinal extension to proximal nail fold or nail matrix), then the nail is partially avulsed and an appropriately sized punch is extended through the nail bed until it contacts the underlying distal phalanx. After hemostasis is obtained, the avulsed portion of nail is sutured in place. Another technique that may prove useful is the “submarine hatch,” an approach that allows access to a lesion by use of two punch biopsies of differing sizes. First, a 6-mm punch is driven through the nail plate to create a window through which the

CHAPTER 15  Common Nail Procedures

FIG. 15.3  Submarine hatch technique. Using a large-

diameter punch, providers may create a window through the nail plate, thus sparing a patient from avulsion or trap door reflection of the entire nail plate. A nail elevator may then reflect the liberated piece of nail plate proximally, revealing the underlying nail bed for intervention. (Courtesy of Martin Zaiac, MD, Miami, FL; with permission.)

lesion is observed. Then, a smaller diameter punch is used to biopsy the lesion. After hemostasis, the portion of nail plate removed is returned and glued into place16 (Fig. 15.3). 

PROCEDURES ON THE PROXIMAL NAIL FOLD AND NAIL MATRIX Procedures conducted on the proximal nail fold may aid in both the diagnosis and treatment of various conditions, including the evaluation of connective tissue disorders and the treatment of acute paronychia. Similarly, tissue samples from the nail matrix may be necessary in the evaluation of longitudinal nail pathology.

Surgical Management of Paronychia Paronychia, or inflammation of the eponychium and/or lateral nail folds, is most commonly caused by trauma to the nail, resulting in inoculation with bacteria. There are varied types of trauma: patients may report recent manicuring, manipulation of the cuticle, or self-induced behaviors such as picking at the proximal nail unit. Regardless of cause, the most common pathogen is Staphylococcus aureus, followed by Streptococcus pyogenes; nevertheless, gram-negative species have been isolated after significant exposure (e.g., bite wounds, thumb sucking). In cases where abscess is not suspected, surgical management should be avoided; topical antibiotic preparations, with or without a topical corticosteroid, are often successful in resolving infection. If recurrent, a course of oral antibiotic therapy with an agent


with appropriate staphylococcal coverage, such as amoxicillin/clavulanic acid, clindamycin, or trimethoprim-sulfamethoxazole, may be warranted.17 If abscess is suspected, then simple incision and drainage is often successful in obtaining source control while simultaneously relieving pain. A culture should be submitted for laboratory analysis to confirm speciation and antibiotic sensitivity. Should infection persist, then deeper exploration may be required, with or without avulsion of the overlying nail. Surgical intervention should be avoided if acute herpetic infection of the digit is suspected.17 In cases of chronic paronychia that are refractory to medical management, physicians may elect to pursue en bloc excision of the proximal nail fold, with or without nail avulsion, for near definitive cure. In elucidating the cause of chronic paronychia, workup should include submission of a sample for fungal cultures/ stains, as well as consideration of an allergic etiology through patch testing. 

Nail Matrix Biopsy Isolated biopsy of the nail matrix may be pursed in the definitive diagnosis of inflammatory disorders, the evaluation of solitary melanonychia, and the diagnosis and/or removal of benign tumors. A trap door reflection of the nail plate proves useful to access the nail matrix. In this approach, the provider makes a 30-degree incision at the junction of the proximal and lateral nail folds. The nail plate is then released using the proximal nail avulsion approach; however, once dissected to the level of the lunula, the nail is then reflected backward, revealing a “trap door” through which the germinal nail matrix may be examined13 (Fig. 15.4). After reflection of the nail plate, providers should perform dermoscopy to determine the origin site of a lesion, as well as select the most appropriate site for biopsy. Such intraoperative dermoscopy may prove especially beneficial in the evaluation of melanonychia, where dermatoscopic patterns, such as regularity of pigment deposition, and presence of pigment globules may raise suspicion of benign versus malignant etiologies.18 After reflection, several biopsy techniques may be selected: matrix punch, matrix shave (tangential), midline (or paramidline) excision, and lateral longitudinal excision (in which all nail tissues distal to the origin site of the matrix lesion are removed en bloc). Regardless of the method of biopsy selected, providers must be aware that removal of >3 mm of tissue from the nail matrix will likely result in scarring and permanent nail deformity, such as split nail.19 


Nail Disorders off-white or gray. In cases of complete matricectomy, patients can be advised that over the course of the next 3 months, the nail bed will keratinize and become firm, restoring to some degree the counterpressure function of the dorsal digit. 

MANAGEMENT OF COMMON NAIL TUMORS Although the techniques discussed earlier will help in the diagnosis and treatment of many nail pathologies, clinicians should be comfortable performing targeted procedures for the treatment of several common nail disorders.

Verruca Vulgaris

FIG. 15.4  Subungual verruca vulgaris, right hand. When

subungual masses compress upon the matrix, they may cause resultant distortions in the nail plate such as leukonychia and contour deformities (left image). In this case, liberation of the nail plate with reflection of the proximal nail fold revealed 0.4-cm subtle hyperkeratotic papule of the nail matrix that was confirmed on histology as verruca (right image). (Images courtesy of Jordan Slutsky, MD.)

Matricectomy Matricectomy, or destruction of the nail matrix, prohibits future growth of the nail. Its use is generally limited to severe nail dystrophies, severe pincer nail, chronic infections refractory to maximal medical treatment, or other conditions for which all medical and surgical options have been exhausted. In the past, surgical excision of the matrix was the modality of choice; however, chemical matricectomy with either 88% phenol solution or 10% sodium hydroxide solution has emerged as the preferred treatment modality. Although some studies demonstrate more definitive cure when a surgical approach is taken, chemical matricectomy is often preferred because of to its lower rates of bleeding, decreased postoperative pain, and lower rates of infection.20–22 Depending on the region of nail affected, partial or complete matricectomy may be performed. After avulsion of the nail, the region of the nail matrix is briskly rubbed with a cotton swab saturated with 88% phenol solution. Two passes are generally sufficient in inducing tissue denaturation, which can be indicated by the color change of tissue to either

Verrucae, the result of infection with various strains of human papillomavirus, are common benign lesions that present as corrugated, hyperkeratotic nodules that vary in size from 5 to 20 mm. They are commonly seen in children, who may present at multiple times throughout childhood with new lesions. Depending on the region of the nail affected, treatment options include cryoablation with liquid nitrogen, chemical ablation with salicylic acid solutions, intralesional injection with bleomycin, and curettage or CO2 laser ablation.23 When exophytic, paring down of more hyperkeratotic lesions before treatment may result in increased procedural success. Patients should be advised that multiple treatment sessions might be required. Furthermore, recurrences at other sites are common. 

Digital Myxoid Pseudocysts Digital myxoid pseudocysts (named as they do not possess the true capsule of a cyst) are common lesions that mostly affect the proximal nail fold. Although their exact mode of pathogenesis is unclear, they are believed to result due to outpouching of either the distal digit tendon sheaths or the distal interphalangeal joints, as well as possible mucin overproduction by digital fibroblasts. Regardless of etiology, these lesions classically appear as shiny, pearloid to near-translucent masses that may be irritated or inflamed. When of significant size, they may cause compression of the nail matrix, thus resulting in contiguous longitudinal depression of the nail plate. Multiple treatment options may be pursued with variable success rates: serial aspiration of pseudocyst fluid, cryosurgery, CO2 laser ablation, and surgical excision. With regard to the latter, the highest success rates have been associated with surgical

CHAPTER 15  Common Nail Procedures excision in which the infundibular connection to the joint space is ligated. In the appropriate setting, intraarticular injections of sterile dyes may help elucidate if the lesion is contiguous with the distal interphalangeal joint space.23,24 

Periungual and Subungual Fibromas Ungual fibromas are papular, flesh- to pink-colored lesions that may affect many regions of the nail unit. Historically, they have been associated with tuberous sclerosis (TSC) complex (seen in upward of 50% of patients with TSC), although they may also arise following trauma in the general population. When numerous, they may serve as an isolated sign of TSC; in this setting, they are often referred to as Koenen tumors. Regardless of etiology, management requires dissection of the lesion down to the phalanx, with en bloc excision of the liberated tissue. When isolated, recurrence after surgical excisions is uncommon; however, recurrences are seen in patients with TSC.23,25 

POSTPROCEDURAL WOUND CARE Following any of the procedures described earlier, any exposed areas of tissue should be gently irrigated with sterile saline and covered with petroleum jelly or an antibiotic ointment such as mupirocin. The nail should be covered with a nonadherent gauze pad and then gently wrapped with soft rolled gauze dressing; bulky, yet nonconstrictive, dressing is advocated to protect against further trauma. If the hand was the site of operation, patients should be advised to keep the hand elevated to the level of the heart for 24–48 h; the foot should be elevated to above 30 degrees, and an open-toed shoe should be worn whenever necessary. Bandages should be removed and replaced every other day or daily if the procedure was conducted to treat an infection. In such cases, oral antibiotics may be indicated. When applicable, nonabsorbable stitches may be removed after 7–14 days depending on the site of operation.2 

SUMMARY AND RECOMMENDATIONS By virtue of its unique structures, procedural interventions on the nail unit may seem daunting for many clinicians. Cognizance of the nail’s unique anatomy, as well as adherence to sterile technique and appropriate postoperative follow-up, will greatly increase the likelihood of successful intervention and preservation of cosmesis, all while minimizing the chance for negative postoperative outcomes.


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19. Jellinek N. Nail matrix biopsy of longitudinal melanonychia: diagnostic algorithm including the matrix shave biopsy. J Am Acad Dermatol. 2007;56(5):803–810. 20. Baran R, Haneke E. Matricectomy and nail ablation. Hand Clin. 2002;18(4):693–696. viii; Discussion 697. Review. 21. Ozdemir E, Bostanci S, Ekmekci P, Gurgey E. Chemical matricectomy with 10% sodium hydroxide for the treatment of ingrowing toenails. Dermatol Surg. 2004;30(1):26–31. 22. Bostanci S, Ekmekçi P, Gürgey E. Chemical matricectomy with phenol for the treatment of ingrowing toenail: a review of the literature and follow-up of 172 treated patients. Acta Derm Venereol. 2001;81(3):181–183.

3. Haneke E. Nail surgery. Clin Dermatol. 2013;31(5):516–525. 2 24. Kim EJ, Huh JW, Park H-J. Digital mucous cyst: a clinicalsurgical study. Ann Dermatol. 2017;29(1):69–73. 25. Liebman JJ, Nigro LC, Matthews MS. Koenen tumors in tuberous sclerosis: a review and clinical considerations for treatment. Ann Plast Surg. 2014;73(6):721–722.