The management of pigmented lesions of the nail bed

Pigmented Nail Lesions: When to Observe, When to Biopsy, When to Widely Excise, and When to Amputate?

Pigmented nail lesions are challenging problems. The differential diagnosis is broad and ranges from common self-limiting conditions, such as subungual hematoma and infection, to potentially fatal conditions, such as subungual melanoma. Clinical assessment and adjuncts, such as dermoscopy and imaging, are usually insufficient to establish a diagnosis, and a nail bed biopsy is often required. However, this is not an innocuous procedure and may result in permanent nail deformity. In addition, subjecting every patient with nail pigmentation to a biopsy will result in an unacceptably high rate of negative test results. Furthermore, histopathologic diagnosis of subungual melanoma remains challenging for several reasons. Once the diagnosis of subungual melanoma is established, the definitive treatment is controversial because the existing guidelines have largely been adapted from those for cutaneous melanoma. This review presents an approach to the diagnosis and management of pigmented subungual lesions and subungual melanoma, in particular, on the basis of the latest available evidence.

Functional Surgery for Subungual Melanoma: Surgical Tips Based on Histological Analysis of 21 Cadavers

BACKGROUND

Amputation has been the standard treatment for subungual melanoma. Although there is growing attention toward a more conservative functional surgery, specific operative techniques are not yet available.

OBJECTIVE

We aimed to provide objective measurements for use in functional surgery by analyzing the anatomy of the nail apparatus obtained from 21 cadavers.

MATERIALS AND METHODS

Nailbed thickness was histologically measured in each subunit, and skin surface anatomy was evaluated to determine the proximal resection margin. Immunohistochemical staining was performed to analyze microvessel distribution according to the nail subunit.

RESULTS

The nailbed thickness was the thinnest at the most proximal point of the nail matrix (thumbs, 1.10 ± 0.42 mm; big toes, 1.15 ± 0.37 mm) and the thickest at the hyponychium (thumbs, 2.86 ± 0.82 mm; big toes, 2.72 ± 0.84 mm). The distance from the eponychium to the skin surface closest to the bony cortex of extensor tendon insertion was 6.92 ± 5.13 mm in thumbs and 5.14 ± 1.59 mm in big toes. The median microvessel density was the highest at the hyponychium (25.74 vessels/mm2) and lowest at the germinal matrix (16.26 vessels/mm2) (p < .05).

CONCLUSION

This histological study offers practical tips, including those to help decide the proximal and deep resection margins, in functional surgery.

Subungual Melanoma

Subungual melanoma is a rare form of melanoma that presents a unique set of challenges largely based on the complex anatomy of the nail unit. Subungual melanoma often first appears with longitudinal melanonychia. Thus, practitioners must have a high clinical suspicion in any patient with longitudinal melanonychia and a low threshold for a biopsy. The "ABCDEF" guide can be a useful tool to aid in screening any lesion of the nail bed. The authors recommend that biopsies of the nail unit be performed by a surgeon with an in-depth understanding of the pathoanatomy of subungual melanoma.

Treatment of Digital Melanonychia with Atypia

BACKGROUND

Melanonychia of the digit is uncommon in the Caucasian population and is concerning because of potential malignant transformation. Several histologic changes occur before malignant transformation, including melanocytic atypia. The authors evaluated patients with melanonychia with melanocytic hyperplasia to determine the risk factors for malignant transformation.

METHODS

The authors retrospectively reviewed records for patients older than 18 years that underwent biopsy for melanonychia. They identified 22 patients with melanocytic hyperplasia with a median age of 61 years (interquartile range, 44 to 71 years). A bivariate analysis was performed to evaluate whether the degree of atypia was associated with malignant transformation and whether treatment choices by surgeons were based on melanocytic atypia.

RESULTS

Following biopsy, patients were followed for a median of 41.0 months (interquartile range, 4.8 to 100.6 months). Melanocytic atypia was present in nine patients and transformed into a malignancy in three: in two patients it became a melanoma in situ, and in one it became an acral lentiginous melanoma. Moderate-severe and severe melanocytic atypia was associated with malignant transformation. After initial biopsy, 14 patients were monitored (11 without atypia and three with atypia). One patient with slight atypia, two patients with moderate-severe atypia, and two patients with severe atypia underwent additional treatment. Patients with melanocytic hyperplasia without atypia were monitored more often (78.6 percent versus 21.4 percent).

CONCLUSIONS

Melanonychia presents a challenge to the hand surgeon, as some patients may be monitored and some should undergo additional resection. Patients with moderate-severe melanocytic atypia following biopsy should undergo resection, and those with mild to slight atypia can most often be monitored clinically.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Current Topics in Nail Surgery

Background:

Nail surgery can be performed in an office-based dermatology practice with a limited amount of specialized equipment and training. Several excellent reviews have been published in recent years that detail the techniques of nail surgery for both the novice and the experienced practitioner.

Objective:

In this article recent developments in nail surgery are discussed. Topics that are treated include the general principles of nail surgery, including epidemiologic issues, studies of nail anatomy, instrumentation, and anesthesia. The reconstruction of injuries and congenital defects involving the nail is explained, and the role of the hand surgeon clarified. Appropriate removal of tumours and cysts is considered, with special attention to the management of malignant lesions. The controversy regarding more or less conservative management of melanonychia striata is addressed, and the need for early diagnosis of subungual melanoma is emphasized. Other topics are surgical management of ingrown nails and onychomycosis. Newer areas of nail surgery, such as laser surgery of the nail, psycho-dermatology of the nail, and the role of primary care physicians in simple nail surgery are also examined.

Surgical options for malignant skin tumors of the hand

Background

Primary malignant tumors of the hand, although unusual, may present varied and often complex clinical problems. The main treatment modality of skin cancer of the hand has changed.

Methods

We retrospectively reviewed the medical records of 43 patients who underwent surgery for malignant skin tumors of the hand during an 18-year period, from September 1994 to February 2012. The characteristics of the tumor, methods of reconstruction, and long-term results were reviewed.

Results

We had 43 patients with 27 melanomas, 14 squamous cell carcinomas, and 2 sarcomas. Their ages ranged from 19 to 74 years (mean, 53.4±14.5 years), from 46 to 79 years (mean, 59.7±9.6 years), and from 15 to 43 years (mean, 29±19.8 years), respectively. Thirty-four cases occurred on the fingertip (16 of those cases on the thumb), 5 cases occurred on the palm, and 4 cases on the dorsum of the hand. Amputation was most frequently used in early cases, but recently, tissue-sparing excision has been performed frequently. The incidence of local recurrence was 3 cases and distant metastasis was 1 case, and the 5-year survival rate was 100%, except in 4 cases due to follow-up loss.

Conclusions

The principles of treatment-to be curative and to preserve function and appearance-are important points. "Preservative surgery" preserves function and cosmesis of the involved finger or hand dorsum or palm. Preservative surgery not only emphasizes less resection and surgery of a smaller scale, but also optimal reconstruction of the soft tissue defect of the digit.

Surgical treatment of malignant melanoma: practical guidelines

Melanoma is currently the fifth and sixth most common solid malignancy diagnosed in men and women, respectively. Although accounting for only 4% of cases of all cutaneous malignancies, melanoma accounts for more than 75% of all deaths from skin cancer. This article discusses epidemiology and risk factors, proper biopsy technique, advanced histologic evaluation of biopsy material, assessment of tumor thickness and staging, preoperative metastatic evaluation, excision margin, treatment of regional lymph nodes, treatment of recurrence, and some special clinical situations.

Melanonychia striata in Chinese children and adults

BACKGROUND

There is considerable racial variation in the occurrence of melanonychia striata. The prevalence of melanonychia striata in the Chinese population is not known. The purpose of this study was to investigate the prevalence and characteristics of melanonychia striata in a Chinese population of patients.

METHODS

Two thousand, four hundred and fifty-seven Chinese patients attending an Asian medical clinic were examined for the presence of melanonychia striata in a cross-sectional prevalence survey. The examinations were carried out as part of the routine medical care provided to these patients. Patients of mixed racial background were excluded. The fingernails and toenails of each patient were examined, and the presence or absence of melanonychia striata, the anatomic distribution of the lesion, and the age and sex of the patient were recorded.

RESULTS

Melanonychia striata was not detected in patients aged less than 20 years. The condition was present in 0.6% of patients aged between 20 and 29 years. Thereafter, the prevalence increased gradually to 1.7% in patients aged 50 years and over. There was a significant relationship between age and the presence of melanonychia striata (chi(2) = 141, P < 0.01). There was no significant sex-related difference in the age-specific prevalence (P > 0.05). The thumbs were most frequently affected, followed by the index fingers (P < 0.001). The condition was bilateral in 40% of cases. None of the patients had involvement of more than two digits.

CONCLUSION

Melanonychia striata is uncommon in Chinese individuals, especially in those aged under 20 years. The male to female ratio is approximately equal. The thumbs are most frequently affected and the condition is often bilateral.

Subungual Melanoma

Melanoma management requires consideration of both oncologic and reconstructive principles to optimize both the likelihood of cure and quality of life. The plastic surgeon is encountering melanoma management that requires not only oncologic but also reconstructive surgery while considering both esthetic and functional results. Management of acrolentiginous melanoma typically involves the partial amputation of the thumb or the toe, with removal of the distal phalanx and the adjacent interphalangeal joint. The simple partial amputation of the second phalanx, preserving the pulp and the interphalangeal function (joints and tendinous insertions), and a made-to-measure ungual transfer provide excellent functional and esthetic results while maintaining similar oncologic outcomes. This report attempts to clarify the management of melanoma of the thumb.

Diagnosis and management of nail pigmentations

Longitudinal pigmentation of the nail is very common. The differential diagnosis varies from subungual hematoma, to a fungal infection, to a melanocytic lesion (lentigo, nevus melanoma, etc.) to others. Often, dermatologists do not feel at ease with these pathologies and management is often not clear. In many cases, a biopsy is not helpful because an inadequate technique was chosen. The use of noninvasive techniques such as dermoscopy has been described to be useful for the preoperative evaluation and the management decision. Using these technique, one will be able to reduce the number of unnecessary surgeries and to choose the most adequate biopsy technique. In this article, we will review the management, including diagnosis as well as differential diagnosis of nail pigmentations and propose a new algorithm for the non invasive diagnosis of nail pigmentation.

Pigmented nail disorders

Nail pigmentation is defined by the presence of melanin in the nail plate. It most frequently has the appearance of a longitudinal pigmented band, called longitudinal mel-anonychia (LM). LM is an important aspect of ungual pathology because it can be the first sign of nail apparatus melanoma. The aim of this article is to help distinguish those types of melanonychia that are worrisome and should lead to biopsy from those that are reasonably reassuring and need only be followed clinically. Histology, differential diagnosis, and biopsy techniques also are considered.

Concomitant traumas influence prognosis in melanomas of the nail apparatus*

BACKGROUND

In nail apparatus melanomas (NAM), the role of standard melanoma prognostic factors is under discussion. The prognostic influence of traumas to the clinically apparent tumour has not been sufficiently examined.

OBJECTIVES

To estimate the influence of traumas against the background of standard prognostic factors on the course of NAM.

METHODS

In 33 patients (20 women, 13 men, median age 65.0 years) with NAM (median tumour thickness 3.5 mm), we retrospectively examined a detailed history of trauma to the affected extremity at first presentation. Histological or other standard prognostic factors and follow-up were studied prospectively using a standardized protocol.

RESULTS

Of 33 patients, 21 had suffered injury to the clinically apparent melanoma primary between 4 and 72 months prior to definitive surgical treatment (diagnostic biopsy up to 3 months ahead of excision of the melanoma was not considered). Eight of these patients had undergone inadequate therapy procedures. In Kaplan-Meier analysis, trauma to the clinically apparent tumour and tumour thickness were found to be significant prognostic factors for recurrence-free survival, and trauma to the clinically apparent tumour, Clark level and tumour thickness were significant prognosis predictors for overall survival. In Cox's proportional hazards model, trauma to the clinically apparent tumour was found to be a significant and independent risk factor with regard to overall survival (hazard ratio 5.39; P = 0.029). An influence of trauma on the primary pathogenesis of NAM could not be confirmed. Only three patients reported trauma prior to the onset of tumour.

CONCLUSIONS

From our data, trauma to the clinically apparent tumour might be a considerable risk factor in NAM. The diagnosis of NAM should be considered in lesions of the nail apparatus and further deterioration of the prognosis due to inadequate therapeutic attempts or injury to the NAM should be avoided.

[Plastic surgery in the treatment of primary cutaneous melanoma]

Surgery is still the most effective treatment modality of skin melanoma. The margins of excision are determined by the thickness of primary tumor. From January 1999 to December 2001, 99 patients (57 male and 42 female, of the average age 55), were surgically treated at the Clinic for Plastic Surgery and Burns of the Military Medical Academy. The most usual localization of the primary tumor was the back (23.23%), followed by the forearm, and the lower leg. Regarding the clinical type of the melanoma, nodular melanoma dominated (62.62%). Microscopic staging of the melanoma (classification according to Clark and Breslow), showed that the majority of patients already suffered from the advanced primary disease, which called for radical excision and the choice of reconstructive methods in the closure of post-excision defects. The reconstructive plastic surgical methods enabled the closure of post-excision tissue defects, regardless of their size, structure, and localization. During the closure of post-excision defects, direct wound closure or split skin draft was performed in 76.76% of patients. Flaps were applied in 19.19% of patients with the primary melanoma of the head, face, foot, and hand. The sufficiency of the available reconstructive procedures makes plastic surgery irreplaceable in the surgical treatment of the primary melanoma of the skin.

Tumors of the perionychium

Tumors of the perionychium are often subtle and difficult to diagnose. Because they are somewhat uncommon, the early symptoms of these tumors, which may include vague pain, local swelling, nail discoloration, nail deformity, or drainage, may be mistaken for signs of infection and/or trauma and therefore treated with topical or oral antibiotics for some time. Functionally important in enhancing fingertip sensation, protection, and manipulating fine objects, the perionychium is continuously subject to day-to-day trauma and injury that can alter the natural contours and growth patterns of the nail plate. Bacterial, viral, or fungal infections can incite swelling, pain, and distortion of the perionychium as well. Both infection and trauma, then, can mask underlying tumors or growths that would delay their diagnosis. A delay in treatment can be devastating if the growth of the perionychium happens to be malignant. Therefore, a general understanding of the signs and symptoms of the perionychium tumors is needed by all physicians and surgeons treating nail problems.

Surgical approaches to malignant melanoma. Practical guidelines

Practical guidelines for the surgical approach to malignant melanoma are discussed in detail. Topics include diagnosis and proper biopsy technique; the appropriate preoperative metastatic workup; width of excision margins; treatment of the regional lymph nodes including cutaneous lymphoscintigraphy, intraoperative lymphatic mapping, and sentinel lymphadenectomy; postoperative follow-up schedules; management of local recurrence including surgical resection, isolated limb perfusion, intralesional therapy, adjuvant immunotherapy; management of special clinical situations including subungal melanoma, plantar melanoma, melanoma on the face, melanoma in pregnancy, and the treatment of lesions of uncertain diagnosis.

[Wedge excision: a new reconstructive technique after longitudinal nail biopsy]

A biopsy is needed when a solitary melanonychia striata in a white patient remains unexplained after careful clinical examination in order to rule out the development of a malignant melanoma. The ideal biopsy has to excise entirely the lesion and to provide enough tissue for pathological examination. The authors describe a new method of excisional biopsy based on primarily closure using a longitudinal closing wedge osteotomy of the distal phalanx. The longitudinal elliptical resection extended from the distal interphalangeal joint to the hyponychium with en bloc resection of the entire thickness of the nail complex, including the periosteum. A longitudinal closing wedge osteotomy was then performed in the distal phalanx allowing primarily closure with precise alignment of the nailbed edges. After suture of the nailbed, a tension band nail synthesis was performed. Four consecutive melanonychia striata of 2 to 3 mm were consecutively operated on using this technique. Postoperative cares were uneventful in all the cases. The pathological examination confirmed the diagnosis of melanoma in one case, Bowen's disease in one and junctional nevus in two. Cosmetic and functional assessment at a mean follow-up of 12 months evidenced light nail dystrophy in all the cases. Our method offers to the pathologist enough tissue with preserved architecture for precise pathological examination. The technically simple closing wedge osteotomy never complicated the postoperative course. These preliminary results are encouraging and allow us to recommend this technique for the diagnosis of all suspect melanonychia striata between 2 and 3 mm wide.

Nail apparatus melanoma

Nail apparatus melanoma is a relatively rare variant of melanoma with a disproportionately high mortality when compared with melanoma elsewhere. The aetiology and natural history remain poorly understood. There is no clear epidemiological association with race, skin type or sun exposure. Universally accepted clinical and histological criteria for the diagnosis of early nail apparatus melanoma have not been defined. The two cardinal clinical signs are melanonychia striata and Hutchinson's sign. These are useful but not pathognomonic of melanoma. Diagnostic delay is frequent and patients commonly have advanced disease at the time of diagnosis. Surgical excision is advocated for treatment of stage I disease; however, the most appropriate re-excision margins, including the level of amputation where required, have not been determined. Early diagnosis and excision of the tumour is the only treatment known to increase survival. Adjuvant systemic chemotherapy, isolated limb perfusion, and routine elective lymph node dissection have been used, but no survival benefit has been demonstrated.

Lymphatic mapping and sentinel lymph node biopsy

Malignant melanoma--cancer of the pigment cells--has the highest mortality rate of all skin cancers. With early detection and treatment, however, malignant melanoma is highly curable. Recently, diagnostic modalities for nodal involvement have been perfected, reducing the morbidity of elective lymph node dissections and rendering them unnecessary in many cases. Total lymphadenectomy procedures are being replaced by intraoperative lymphatic mapping and sentinel lymph node biopsy using gamma detector probes. This article reviews lymphatic drainage from the primary site to possible lymph node basins and selective lymph node dissection using lymphoscintigraphy and intraoperative mapping as guides. This article also includes a case study, beginning with a diagnosis of malignant melanoma and following a successful postoperative course.