Nail Unit Blue Nevi: A 11-Case Series and Review of the Literature

Background

Blue nevus of the nail apparatus is a rare entity and only isolated cases are reported in the literature.

Objective

The aim of this study was to better characterize blue nevus at the nail unit.

Methods

Retrospective analysis of all nail unit blue nevi from the Nail Group of the French Society of Dermatology was compared to the literature.

Results

Eleven cases were retrieved from 2002 to 2019 with an average age of 45 years. The majority were women (9/11) and acquired (10/11). Hands were more frequently involved (9/11) with a predilection for the thumb and 2 cases were located on the hallux. Nail unit blue nevus mostly presented as a well-delimited blue spot of the lunula (9/11) and histologically was of the common type (10/11). There was no malignancy.

Conclusion

Nail unit blue nevus is a rare asymptomatic benign entity, mostly acquired on the thumb or the hallux of women. The most frequent presentation is a painless blue spot on the lunula. Congenital blue nevi seem to only affect the paronychium. Main differential diagnosis is melanoma and histopathological examination is mandatory.

Isolated nail lichen planus: An expert consensus on treatment of the classical form

Lichen planus is a benign inflammatory disorder of unknown etiology that may affect the skin, mucosae, scalp, and nails. When the nails are affected, it may lead to permanent destruction with severe functional and psychosocial consequences. Therefore, prompt diagnosis and early treatment are essential, even in mild cases. There are currently no guidelines for the management of nail lichen planus and the published literature on treatment is limited. The aim of this review is to provide practical management recommendations for the classical form of nail lichen planus, especially when restricted to the nails. Topical treatment has poor short-term efficacy and may cause long-term side effects. Instead, intralesional and intramuscular triamcinolone acetonide should be considered first-line therapies. Oral retinoids are second-line choices, and immunosuppressive agents may also be considered.

Bidet nail syndrome: report of a typical case

Worn-down nail syndrome is a nail disorder characterized by thinning of the distal nail plate induced by repetitive mechanical trauma. A French variant, entitled "bidet nail syndrome" was first described by Baran.

[Cosmetic nail products]

Cosmetic embellishment of fingernails involves the use of substance that harden either after the evaporation of solvents (varnishes) or after polymerisation (artificial acrylic nails, gel tips, glue-on artificial nails). Pathological reactions to cosmetics usually occur at a remote site for varnishes, and, most commonly, in situ with polymerising substances. Unvarnished artificial nails do not affect pulse oximetry readings, and in theory, patients are not required to remove them. However, a real problem of contamination via artificial nails exists. Increased carriage of pathological Gram-negative organisms and of Staphylococcus aureus and yeasts has been noted among nursing staff wearing artificial nails, both before and after fingernail cleaning. Fingernail fragility manifests itself through a number of different physical signs such as soft, breaking nails, with longitudinal or transverse fissures, showing distal doubling or friability. In some subjects, excessive manicuring with metal instruments or manicure sticks results in rolled onycholysis, of evocative appearance, or transverse onycholysis.

[Key messages in nail disease]

Nail diseases are varied, and their diagnosis is often difficult. Misdiagnosis can result in failure to recognize a severe disease in urgent need of treatment and in the prescription of treatments that are inappropriate, long, ineffective, and expensive. Acute paronychia must be managed rapidly, treated with antiseptics several times a day, and closely monitored. Nail lichen must be recognized early and treated rapidly and appropriately to prevent permanent scarring. All chronic pain (to shocks or cold) of the tip of a finger or toe should suggest a glomus tumor. Any unexplained persistent single-finger onychopathy should in principle cause the physician to suspect a tumor, carcinoma, or melanoma and to order a histologic examination. An onychopathy must not be treated as an onychomycosis without diagnostic certainty. Repeated microtraumas of the toenails cause injuries that absolutely must be differentiated from onychomycosis. In growth of the big toenail can often be avoided by appropriate cutting of the nails, leaving in place the lateral parts of the nail plate.

Recurrent glomus tumors of fingertips: MR imaging evaluation

PURPOSE

To determine the magnetic resonance (MR) imaging findings in recurrent glomus tumors of the fingertips.

MATERIALS AND METHODS

Twenty-four consecutive patients with recurrent pain after previous excision of a glomus tumor of the fingertip underwent MR imaging studies and surgery. T1-weighted spin-echo MR images were obtained in each patient before and after intravenous injection of contrast material; T2-weighted spin-echo and three-dimensional gradient-recalled echo images were also obtained. MR angiography was performed in four patients. Postsurgical histopathologic analysis revealed recurrent glomus tumors in 22 patients. Signal intensity, enhancement, and margins of the scar tissue and the recurrent tumors at MR were assessed.

RESULTS

The postsurgical scars were depicted in 21 (88%) of 24 patients with all sequences but were best demonstrated on gradient-recalled echo MR images. Seven patients had undergone multiple surgical procedures and had extensive scar tissue and, in one case, a neuroma. In all patients, MR imaging revealed a nodule compatible with the diagnosis of a recurrent glomus tumor. In 13 (54%) of 24 patients, the nodule had typical features of a glomus tumor. In eight (33%) of 24 patients, the tumors had low signal intensity or isointensity compared with the nail bed on T2-weighted images. In six (25%) of 24 patients, the tumors had faint enhancement after intravenous gadolinium chelate administration. The margins of the tumors were blurred by scar tissue in nine of 24 cases.

CONCLUSION

MR imaging can aid in the evaluation of recurrent glomus tumors.

Hemangiomas of the fingers: MR imaging evaluation

PURPOSE

To report the magnetic resonance (MR) imaging features of finger hemangiomas.

MATERIALS AND METHODS

Sixteen patients clinically suspected of having hemangioma of the finger underwent 1.5-T MR imaging with a customized local gradient coil. The location, size, margins, signal intensity, and enhancement patterns of the lesions were noted. In accordance with the literature on MR imaging of deep hemangiomas, the authors' findings could be divided into those with typical features-that is, high signal intensity at T1- and T2-weighted imaging, lobulated appearance, strong enhancement, and heterogeneous pattern with flow void artifacts-and those with atypical features. The reference standard was surgery (n = 12) or clinical outcome (n = 4).

RESULTS

One posttraumatic hematoma was excluded. Most lesions were in the fingertip (n = 10), with involvement of the nail bed and/or the pulp (n = 5). Hemangiomas were classified as typical in ten cases and atypical in five. The mean size of typical lesions was larger than that of atypical lesions. The unique imaging features of atypical hemangiomas included a masslike appearance, which was either homogeneous with diffuse enhancement-suggestive of hypervascularity (n = 2)-or heterogeneous with poor enhancement (n = 3).

CONCLUSION

MR imaging characteristics of finger hemangiomas can be classified as typical or atypical. Knowledge of both patterns can be helpful in the distinction of soft-tissue abnormalities at this location.

[Nail pathology in children]

In children the nail has physiologic characteristics that imply specific abnormalities. The most common dermatological localisation in psoriasis in the child; it is seen as trachyonychia, pitting, and occasionally pachyonychia. Ingrowth of the large toenail is a common problem, whether due to congenital hypertrophy of the lateral nail folds of the hallux in the newborn, to congenital malalignment of the nail of the big toe, or to a juvenile ingrown nail. Many other nail disorders are observed in the child: parakeratosis pustulosa, nail lichen, lichen striatus, melanonychia, dermatophyte onychomycosis, candida infection, herpes.... Aside from warts, tumours are rare.

[Pigmented lesions of the nail apparatus]

Linear pigmentation of the nail apparatus most reflects longitudinal melanonychia. It results either from simple activation of matrical melanocytes induced by various factors or from benign (lentigo or naevus) or malignant (melanoma) melanocyte hyperplasia. Hematomas and some fungal infections can falsely resemble linear pigmentation. Non-linear pigmented lesions of the nail bed are most often subungual hematoma or infections (fungal, or pyocyanic superfection of a loosened or separated nail). Opening the nail bed directs the diagnosis. A possible tumoral cause should be kept in mind, especially melanoma, or carcinoma.

A randomized trial of amorolfine 5% solution nail lacquer combined with oral terbinafine compared with terbinafine alone in the treatment of dermatophytic toenail onychomycoses affecting the matrix region

In view of recent advances in the development of antifungal agents, this study examined the possible synergy of two new antifungal agents, terbinafine and amorolfine. The study compared two different courses of terbinafine treatment combined with amorolfine 5% solution nail lacquer. Terbinafine was given orally for 6 (AT6 group) or 12 weeks (AT12 group) and amorolfine nail lacquer applied weekly for 15 months. A control group received terbinafine alone for 12 weeks. This was a randomized, prospective, open study of severe dermatophyte toenail onychomycosis with matrix region involvement. Nail samples were taken before the start of the study, at inclusion and at the visits at 6 weeks, 3, 9, 15 and 18 months. To assess the value of such combined therapy we chose an early parameter as the principal outcome variable, which was the result of mycological examination, including direct microscopy and culture, at 3 months (allowing a margin of 15 days). The secondary parameters of success were the mycological results at the later visits, clinical evaluation and a combined mycological-clinical response. Safety and tolerance were also assessed. Adverse events were recorded and liver function tests were performed monthly during the terbinafine treatment. Of the 147 patients included in the trial, 121 attended the 3-month visit, within a time limit of 15 days of 3 months after the beginning of treatment: 40 in the AT6 group, 40 in the AT12 group and 41 in the control group. In all, 32 of 121 patients (26. 4%) had negative mycological results on direct microscopy and culture: 14 of 40 (35.0%) in the AT6 group, 11 of 40 (27.5%) in the AT12 group and seven of 41 (17.1%) in the control group. The cure rate for the global (mycological and clinical cure) response measured at 18 months in 145 patients was 44.0% (22 patients) in the AT6 group, 72.3% (34 patients) in the AT12 group and 37.5% (18 patients) in the terbinafine group. These results suggest that the combination of amorolfine and terbinafine may be of value in the treatment of severe onychomycosis. At the same time a pilot pharmacoeconomic analysis was performed demonstrating a better cost per cure ratio for the patients receiving combination treatment.

Onychomatricoma: clinical and histopathologic findings in 12 cases

BACKGROUND

Onychomatricoma is a nail matrix tumor that has been well characterized clinically but not histologically.

OBJECTIVE

The purpose of this study was to establish histologic criteria for the diagnosis of onychomatricoma to differentiate it from other fibroepithelial tumors of the nail matrix.

METHODS

We observed 12 cases and were able to examine 4 of these excised specimens, including the attached nail plate. In 8 patients, avulsion of the nail was performed before excision of the tumor so that the nail plate was examined separately from the tumor.

RESULTS

Onychomatricoma is a fibroepithelial tumor consisting of 2 anatomic zones. The proximal zone is located beneath the proximal nail fold with a proximal border starting at the root of the nail and distal border corresponding to the cuticle. It is characterized by deep epithelial invaginations filled with a thick V-shaped keratogenous zone, a thickened nail plate without cavitation but with an undulating inferior border ending in ungual spurs, and a fibrillary stroma clearly demarcated from the undersurface. The distal zone corresponds to the lunula and is characterized by multiple "glove finger" digitations lined with matrix epithelium and oriented around antero-oblique connective tissue axes; perforation of the nail plate by multiple cavities that, generally at the distal edge of the lunula, lose their epithelial digitations and become filled with serous fluid; the connective-tissue stoma of the digitations extends deeply into the dermis and is not demarcated form healthy tissue.

CONCLUSION

On the basis of the mentioned characteristics, we have been able to define onychomatricoma histologically. In addition, we have identified an unusual clinical form of onychomatricoma that has the appearance of a cutaneous horn and is situated at the junction of the undersurface of the proximal nailfold and the lateral nailfold.

Distal digital keratoacanthoma: a report of 12 cases and a review of the literature

Twelve cases of distal digital keratoacanthoma (DKA) affecting the subungual area or the proximal nail fold are reported. The distal phalanx of the toe was affected in three cases. Spontaneous resolution occurred in one; one other recurred after surgery. We also discuss the link between DKA and incontinentia pigmenti subungual tumours; these entities are indistinguishable.

Standard and high resolution magnetic resonance imaging of glomus tumors of toes and fingertips

BACKGROUND

High-resolution magnetic resonance imaging (MRI) of subungual glomus tumors has been recently reported.

OBJECTIVE

Our purpose was to compare high-resolution MRI and standard MRI for the diagnosis of 44 glomus tumors of the toes and fingertips.

METHODS

Glomus tumors (11 cases) were first examined by MRI with a commercial surface coil (set 1). Thirty-three other glomus tumors and one tumor from set 1 were then examined with a high-resolution module designed for skin imaging (set 2).

RESULTS

All 44 glomus tumors were identified with MRI. The limits of the tumors were detected in 54% of set 1 and 100% of set 2. A capsule was present in most cases, but was incomplete or absent in eight cases. Subtypes of glomus tumors were more easily differentiated in set 2.

CONCLUSION

Standard MRI was adequate to detect glomus tumors, but high-resolution MRI assessed tumor characteristics more accurately.

MR imaging of digital mucoid cysts

PURPOSE

To assess the usefulness of magnetic resonance (MR) imaging in the diagnosis and clarification of the physiopathology of digital mucoid cysts.

MATERIALS AND METHODS

Twenty-three patients (14 women, nine men; aged 52-75 years) with mucoid cysts underwent MR imaging at 1.5 T with a local surface gradient coil. The pixel size was 117 microns in one direction. T2 relaxation times were measured. Contrast material was intravenously administered in 15 patients.

RESULTS

All mucoid cysts had high signal intensity and sharp borders on T2-weighted images. Intracystic septa were present in nine patients (39%). Most cysts were solitary (n = 13) and/or in the proximal nail fold (n = 16). Satellite cysts were present in five patients. Nineteen patients (83%) had cysts with pedicles that extended to the joint. Osteoarthritis of the distal interphalangeal joint was present in 16 patients (70%). Five patients (22%) had multiple flattened cysts that were usually independent of the joint. In seven patients (30%), MR images showed cysts beneath the nail plate.

CONCLUSION

Digital mucoid cysts may be polymorphic. MR imaging is helpful when cysts are in the nail bed.

The lunula: a magnetic resonance imagining approach to the subnail matrix area

High-resolution sagittal magnetic resonance images depict an oval area in the dermis beneath the nail matrix that gives a particular signal. This study defines the magnetic resonance imaging characteristics of this area and examines its correlation with the lunula. A high-resolution surface gradient coil specially designed for skin imagining was used on a 1.5 T magnetic resonance unit. The subnail matrix (SNM) areas of 12 subjects had a significantly longer T2 relaxation time and a higher enhancement ratio after injection of gadolinium than did the nail bed dermis. The length of the SNM area distal to the free edge of the proximal nail fold was highly correlated with the length of the lunula (R = 0.98) in 30 fingers and 10 toes. The total length of the SNM area was somewhat correlated with the nail thickness (R = 0.86) in 30 fingers. The histology and microvascularization of the subungual tissue in 21 fingers showed that this SNM area had specific features: The area was composed of loose connective tissue without bundles, and the reticular and subdermal vascular networks had large regular meshes in this oval area. The lunula is shown to be linked to a well-defined area in the underlying dermis with a specific histology and microvascularization.

Subungual glomus tumors: evaluation with MR imaging

PURPOSE

To determine the magnetic resonance (MR) imaging features of subungual glomus tumors.

MATERIALS AND METHODS

Thirty-one patients with a clinical suspicion of glomus tumor and 10 control subjects underwent MR imaging at 1.5 T. MR images of normal glomus bodies of a cadaver finger were correlated with histologic slices. With a local surface gradient coil, the pixel size reached 117 microns in one direction. Relaxation times were measured. Gadoterate meglumine was injected in 19 patients.

RESULTS

Normal glomus bodies were visualized in the reticular dermis of the nail bed. Twenty-seven of 28 pathologically confirmed glomus tumors were detected with MR imaging. A peripheral capsule was present in most tumors. The nail matrix was compressed in 13 cases. The authors were able to differentiate three subtypes of glomus tumors (vascular, solid, and myxoid) on the basis of relaxation times and enhancement characteristics. Four patients had mucoid cysts or angioma in the nail bed.

CONCLUSION

MR imaging can help accurately define the location and limits of glomus tumors before excision.

Magnetic resonance imaging: a new tool in the diagnosis of tumours of the nail apparatus

Tumours of the nail apparatus are often the subject of diagnostic dilemma. Until now, no reliable imaging methods have been available to assess these lesions correctly. We report the results of high and very high-resolution magnetic resonance imaging (MRI), which have been correlated with the anatomical findings in 14 cases of nail apparatus pathology, and discuss the possible contribution of MRI to diagnosis. With very high-resolution MRI, accurate analysis of the anatomy of the nail apparatus is possible, and lesions as small as 1 mm can be detected. An expansive process can be excluded when results are negative. Glomus tumour, mucoid pseudocyst, fibrokeratoma, and exostosis can be differentiated because of their different MRI characteristics. This is of importance when the exact nature of a subungual tumour cannot be determined by clinical findings alone. Measurement, determination of the exact localization of the tumour, and the study of its relationship to the other structures, can provide guidance for subsequent surgical procedures. MRI is reliable and accurate in the delineation of lesions, and provides a new tool for the investigation of pathology of the nail apparatus.

Nail bleeding associated with neurological diseases: all that uncommon? Report of 3 cases

We report 3 patients, without bleeding disorders, presenting with onychomadesis and focal haemorrhages at multiple proximal nail folds or in the nail tissue. In one of our patients it was possible to check the appearance of a drop of blood on each side, beneath the proximal nail fold when he pressed the pulp of the fingers of his previously fractured forearm on a hard surface. All patients had major peripheral or major peripheral and central neurological deficits, prior to the nail bleeding. Peripheral vascular dilatation produced by paralysis of the vasoconstrictors in the nail area slows the venous return in the dilated vessels, mainly in the proximal nail fold.