Dermoscopic features of digital mucous cysts: A study of 23 cases

Examination of the nails: Main signs

Understanding the anatomy of the nail apparatus is a prerequisite for diagnosing and managing various nail disorders. The latter may be associated with systemic pathologies, or accompany infectious, inflammatory, tumoral, toxic or traumatic dermatoses. Before attempting to identify the cause, a rigorous clinical examination should be conducted to screen for elementary lesions that may affect general nail shape, nail surface, subungual attachments, periungual soft tissue or nail color. All of these guide differential diagnosis.

Diagnosis and surgical treatment of benign nail unit tumors

Little is known about benign non-melanocytic nail tumors, probably due to their low pathogenicity. They are commonly misdiagnosed as inflammatory or infective diseases. They have various features, depending on the type of tumor and its location in the nail apparatus. The typical sign of a tumor is the presence of a mass and/or secondary nail changes from damaged nail structures. In particular, if a single digit is affected by a dystrophic sign or a symptom is reported without any explanation, the presence of a tumor should always be ruled out. Dermatoscopy helps to enhance visualization of the condition and in many cases supports the diagnosis. It may also assist in identifying the right place to biopsy, but it never replaces surgery. Most common non-melanocytic nail tumors are analyzed in this paper, including glomus tumor, exostosis, myxoid pseudocyst, acquired fibrokeratoma, onychopapilloma, onychomatricoma, superficial acral fibromyxoma and subungual keratoacanthoma. The aim of our study is to review the main clinical and dermatoscopic characteristics of the most common benign non-melanocytic nail tumors, to correlate them with the histopathology and to advise practitioners of the best surgical management.

Causes of longitudinal nail splitting: a retrospective 56-case series with clinical pathological correlation

BACKGROUND

Split nail (SN) is a rare type of nail fragility syndrome, characterized by a longitudinal fissure involving the entire thickness of the nail plate. Longitudinal nail splitting may be caused by direct injury to the nail plate or matrix insult. Few articles have been published on the topic, most were related to the traumatic aetiology. Some case reports mention tumours and inflammatory disorders as other causes.

OBJECTIVES AND METHODS

The aim of this retrospective study was to analyse the clinical and histopathological features of 56 SN collected at the nail consultation of the dermatology department at Saint Pierre University Hospital in Brussels, between 1997 and 2019.

RESULTS

Fifty-six patients were included (34 women and 22 men) with median age of 44.2 years. The fingernails were 3.2 times more frequently affected than toenails, especially the thumb. The most frequent aetiologies were tumours (45.6%), inflammatory diseases (26.3%) and traumas (19.3%). Congenital (5.3%) and systemic disorders (3.5%) were rarer causes. Histopathological slide review confirmed that alteration of the nail matrix integrity causes split nail, resulting either from matrix stretching by an underlying tumour or from impairment of the keratinization process by inflammatory diseases, melanocytic tumours and Bowen's disease.

CONCLUSIONS

This study is the largest case series of longitudinal nail splitting to date. It is the first to gather nail disorders causing SN with their clinical pathological correlation. The most common causes are traumatisms, tumours and inflammatory disorders. Congenital and systemic disorders are rarer. Tumours are responsible for half of the cases from which one third are malignant, mainly melanoma. When facing a monodactylic SN, benign as well as malignant tumours should be ruled out before concluding to traumatic aetiology.

Frequency of Publication of Dermoscopic Images in Inter-observer Studies: A Systematic Review

Research interest in dermoscopy is increasing, but the complete dermoscopic image sets used in inter-observer studies of skin tumours are not often shared in research publications. The aim of this systematic review was to analyse what proportion of images depicting skin tumours are published in studies investigating inter-observer variations in the assessment of dermoscopic features and/or patterns. Embase, MEDLINE and Scopus databases were screened for eligible studies published from inception to 2 July 2020. For included studies the proportion of lesion images presented in the papers and/or supplements was extracted. A total of 61 studies (53 original studies and 8 shorter reports (i.e. research letters or concise reports)). published in the period 1997 to 2020 were included. These studies combined included 14,124 skin tumours, of which 373 (3%) images were published. This systematic review highlights that the vast majority of images included in dermoscopy research are not published. Data sharing should be a requirement for future studies, and must be enabled and standardized by the dermatology research community and editorial offices.

Digital Myxoid Cysts: Correlation of Initial and Long-Term Response to Steroid Injections

BACKGROUND

Digital mucous cysts (DMCs) are benign myxoid pseudocysts that develop on the distal interphalangeal joint's lateral or dorsal aspects. Management consists either of a surgical approach, conservative therapy, or simple follow-up.

OBJECTIVE

To correlate the initial and long-term response with clinical and ultrasound parameters in DMCs treated with intralesional steroids as first-line therapy.

METHODS

A single-center prospective open-label study recruited 15 patients affected by DMCs, who had been treated with a cycle of up to 3 steroid injections at a 6 to 9 week time interval.

RESULTS

At the first follow-up visit, 53.3% of patients were cleared of DMCs, achieving a complete response, whereas 46.7% experienced a >30% decrease in their DMC volume, and were considered partial responders. After 1 year of follow-up, the cure rate decreased to 40%, and the recrudescence rate was 27.3%. Clinical and sonographic characteristics that positively correlated with a maintained complete response at follow-up were as follows: young age, absence of osteophytes, low volume, complete clearance at T1, and short disease duration (p < .05).

CONCLUSION

Intralesional steroid therapy is an easy approach for DMC, with minimal side effects; identifying predictive hallmarks is useful to offer a straightforward surgical treatment to patients who have nonresponder characteristics.

Dermoscopy of venous lake on the lips: A comparative study with labial melanotic macule

BACKGROUND

Venous lake (VL) is a common vascular tumor occurring on the lips in the elderly. VL is sometimes difficult to distinguish from melanotic lesions such as labial melanotic macule (LMM) or oral malignant melanoma. However, the dermoscopic features of VL have not been sufficiently established in the literature.

OBJECTIVE

This study was aimed at investigating the dermoscopic features of VL on the lips, and to compare the dermoscopic features of VL with those of LMM.

METHODS

We retrospectively investigated the dermoscopic findings of histopathologically proven cases of VL and LMM.

RESULTS

The structureless pattern (78.6%) and globules/clods (42.9%) were the common patterns in VL cases. Purple was the most frequent color (78.6%), followed by red (42.9%) and blue (42.9%). The structureless pattern (p = 0.003) and the colors purple (p = 0.000), red (p = 0.003), and blue (p = 0.018) were significantly more common in VL than in LMM. In contrast, lines (p = 0.000) and dots (p = 0.044) as patterns, and brown (p = 0.000) and gray (p = 0.044) colors were significantly more frequent in LMM. White structures were more common in VL than in LMM (p = 0.001).

CONCLUSION

Structureless patterns or globules/clods with purple, red, or blue coloration can be useful findings when differentiating VLs from LMM on dermoscopy. Therefore, dermoscopic evaluation is a helpful noninvasive ancillary tool in the diagnosis of VL.