Tangential Biopsy Thickness versus Lesion Depth in Longitudinal Melanonychia: A Pilot Study

Role of tangential biopsy in the diagnosis of nail psoriasis

BACKGROUND

Histopathology can be crucial for diagnosis of inflammatory nail diseases. Longitudinal excision and punch biopsies are the most used techniques to obtain the tissue sample. However, there is a low clinical-histopathological correlation, besides the risk of nail dystrophy. Tangential excision biopsy (TB) is a well-established technique for the investigation of longitudinal melanonychia. TB could also be used to evaluate diseases in which histopathological changes are superficial, as in psoriasis.

OBJECTIVE

To study the value of TB in the histopathological diagnosis of nail psoriasis.

METHODS

This is a prospective and descriptive study of the clinical-histopathological findings of samples from the nail bed or matrix and nail plate of 13 patients with clinical suspicion of nail psoriasis. Biopsies were obtained through partial nail avulsion and TB.

RESULTS

In nine patients, the hypothesis of psoriasis was confirmed by histopathology; in one, the criteria for diagnosing nail lichen planus were fulfilled. The tissue sample of only one patient did not reach the dermal papillae, and, in four of 13 patients, the adventitial dermis was not sampled. No patient developed onychodystrophy after the procedure.

STUDY LIMITATIONS

In three patients, the clinical and, consequently, histopathological nail changes were subtle. Also, in one patient's TB didn't sample the dermal papillae.

CONCLUSIONS

TB is a good option to assist in the histopathological diagnosis of nail psoriasis, especially when appropriate clinical elements are combined. Using this technique, larger and thinner samples, short postoperative recovery time, and low risk of onychodystrophy are obtained.

Mimical reconstruction and aesthetic repair of the nail after resection of subungual melanocytic nevus

Background

This study aimed to report the outcomes of mimical reconstruction and aesthetic repair of the nail.

Methods

When the pigmented bands were more than 1/2 the width of the whole nail, mimical reconstruction of the nail was performed, with a lateral toe pulp island flap covering the wound via the subcutaneous channel. If the pigmented bands were 1/4 to 2/5 the width of the entire nail, aesthetic repair of the nail was carried out by split-thickness excision under a microscope.

Results

The average age of patients at the time of surgery was 14.5 years. Five patients had lesions on their toes, while three had lesions on their fingers. There were no post-operative complications. All toenails of the five patients who had undergone mimical reconstruction exhibited a well-settled flap. The nails of the three patients who underwent aesthetic repair displayed no nail malnutrition or deformity, and all nails had an aesthetic appearance.

Conclusions

Both mimical reconstruction and aesthetic repair of the nail following resection of subungual melanocytic nevus are reliable and feasible. The “like tissue” repairs of complex nail defects appear to be satisfactory. All patients had excellent aesthetic outcomes.

Level of evidence

V

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01423-9.

Nail Surgery: Six Essential Techniques

Successful nail surgery requires an understanding of specific disease processes, the anatomy of the nail unit, and fluency with only a few key techniques. This article focuses on 6 high-yield procedures, facility with which will allow the clinician to approach most of the clinical scenarios requiring surgical intervention. These encompass surgical approaches to inflammatory nail diseases, melanonychia, erythronychia, and nail melanoma in situ.

Diagnosis of Melanonychia

Melanonychia has many causes and can involve one or several fingernails or toenails, and may occur at any age. Dermoscopy is used routinely in the evaluation of a pigmented nail. If pigmentation is caused by melanin produced by nail matrix, identify whether the pigmentation is caused by an activation or proliferation of nail melanocytes. When melanocytic proliferation is suspected, biopsy with histopathologic examination is the gold standard for diagnosis and is recommended when a longitudinal melanonychia occurs in an adult and is localized in a single digit, in the absence of local or systemic causes that may explain its onset.

Early Detection of Subungual Melanoma In Situ: Proposal of ABCD Strategy in Clinical Practice Based on Case Series

Background

Prevalence of subungual melanoma (SUM) in Asian population is relatively high and early clinical detection improves both quality of life and survival.

Objective

We sought to establish screening strategy for SUM in situ.

Methods

We retrospectively reviewed medical records of 8 patients pathologically diagnosed as SUM in situ between January 2015 and September 2016.

Results

All patients in our study were adults and had solitary lesion. In all cases, longitudinal melanonychia as well as background pigmentation in entire nail plate was observed. Seven (87.5%) cases had periungual pigmentation. Clinical features of SUM in situ can be summarized according to new criteria categorized under initial letters of alphabet, namely nail ABCD of SUM in situ; “A” stands for adult age (age >18 years); “B” for brown bands in brown background; “C” for color in periungual skin; “D” for one digit. Our strategy was to suspect SUM in situ if solitary longitudinal melanonychia in adult was satisfying either “B” or “C” in ABCD. All cases were suspected as SUM in situ under nail ABCD rule, and histological examination confirmed diagnosis. Sensitivity and specificity of nail ABCD was 100% and 96.6%, respectively, regarding our previously published 18 SUM in situ and unpublished 28 nail matrix nevi cases as well as 8 SUM in situ presented here.

Conclusion

ABCD rule is simple and sensitive clinical strategy for early detection of SUM in situ.

"Dots and lines": A melanonychia striata in regression: Report of a case

A 2-year-old Caucasian boy with melanonychia striata with multiple striking pits on the nail plate of one fingernail is described. Nail disorders often pose diagnostic and therapeutic challenges for clinicians, especially melanonychia striata, because of the fear of a subungual melanoma. Only a few childhood cases of melanonychia striata have been described, and the multiple pits are even less common. Dots distributed along melanotic lines is a finding referred to as "dots and lines" and can be a sign of regression of melanonychia in childeren.

Dermatologic Manifestations of the Lower Extremity: Nail Surgery

Nail surgery is a fundamental component of podiatric surgery. Nail disorders are common and may cause significant morbidity and occasionally mortality. Diagnosis of inflammatory and infectious conditions, and of benign or malignant tumors, often requires a biopsy of the nail unit. Excisional surgery may also be curative for certain tumors. This article reviews key elements of nail anatomy, surgical preparation, local anesthesia, and methods to achieve and maintain a bloodless field. A familiarity with these concepts should allow clinicians to develop a surgical plan and approach when patients present with a nail disorder requiring biopsy or surgical treatment.

Guidelines of the Brazilian Dermatology Society for diagnosis, treatment and follow up of primary cutaneous melanoma--Part I

The last Brazilian guidelines on melanoma were published in 2002. Development in diagnosis and treatment made updating necessary. The coordinators elaborated ten clinical questions, based on PICO system. A Medline search, according to specific MeSH terms for each of the 10 questions was performed and articles selected were classified from A to D according to level of scientific evidence. Based on the results, recommendations were defined and classified according to scientific strength. The present Guidelines were divided in two parts for editorial and publication reasons. In the first part, the following clinical questions were answered: 1) The use of dermoscopy for diagnosis of primary cutaneous melanoma brings benefits for patients when compared with clinical examination? 2) Does dermoscopy favor diagnosis of nail apparatus melanoma? 3) Is there a prognostic difference when incisional or excisional biopsies are used? 4) Does revision by a pathologist trained in melanoma contribute to diagnosis and treatment of primary cutaneous melanoma? What margins should be used to treat lentigo maligna melanoma and melanoma in situ?

Tangential excision of pigmented nail matrix lesions responsible for longitudinal melanonychia: evaluation of the technique on a series of 30 patients

OBJECTIVES

We sought to assess the shave biopsy technique, which is a new surgical procedure for complete removal of longitudinal melanonychia. We evaluated the quality of the specimen submitted for pathological examination, assessed the postoperative outcome, and ascertained its indication between the other types of matrix biopsies.

DESIGN

This was a retrospective study performed at the dermatologic departments of the Universities of Liège and Brussels, Belgium, of 30 patients with longitudinal or total melanonychia.

RESULTS

Pathological diagnosis was made in all cases; 23 patients were followed up during a period of 6 to 40 months. Seventeen patients had no postoperative nail plate dystrophy (74%) but 16 patients had recurrence of pigmentation (70%).

LIMITATIONS

This was a retrospective study.

CONCLUSIONS

Shave biopsy is an effective technique for dealing with nail matrix lesions that cause longitudinal melanonychia over 4 mm wide. Recurrence of pigmentation is the main drawback of the procedure.