Clinical characteristics of intradermal nevus in the external auditory canal.

Melanocytic nevus occurring in the external auditory canal (EAC) is uncommon. Therefore, in the absence of sufficient clinical experience, this disease may be challenging to be suspected even with a physical examination. Herein, clinical and demographic features of intradermal nevus in the EAC were investigated. Patients with an intradermal nevus on histopathological examination (n = 15; 2 men and 13 women; P = .005) were included from a pool of patients who underwent surgical resection for EAC tumors between November 2011 and March 2022. Data were retrospectively collected on their sex, appearance of the lesions, surgical method, and outcomes. Nine patients had a dome shape and 6 patients had a papillomatous shape. Ten patients had dark colors and 5 patients had pale colors. All pale colors appeared only in the dome-shaped nevus, and only dark colored papillomatous nevi were observed. A significant difference was noted in terms of the frequency of occurrence by colors (dark or pale) according to shape (dome or papillomatous) (P = .044). No patient showed recurrence or EAC stenosis after circumferential excision. In women, a dome-shaped or papillomatous mass with dark color in the EAC may likely be predicted as the nevus. However, it can also occur in men, and even if it is a pale color, in the case of a dome shape, taking the nevus into account is important. Moreover, successful treatment outcomes were achieved through circumferential excision.

Melanoma Developing from an Intradermal Nevus: Report on Two Patients.

Dear Editor, Approximately 25-33% of cutaneous melanomas arise from nevi (1). Shitara et al. suggested that junctional and compound nevi are more likely give rise to melanoma than intradermal nevi, but this has not been definitively confirmed (2). Based on these results and our own clinical observation on rare malignant transformation in intradermal nevi, we present two patients with melanoma developing from an intradermal nevus. The first patient, a 63-year-old woman, presented with a suspicious lesion in 2017 on the upper back in the form of a dark brown macula juxtapositioned next to the dermal nevus (Figure 1, a). Dermoscopy of a flat part showed a dark-brown reticular, slightly structureless pattern (Figure 1, b). The patient was therefore referred to surgical excision. Histopathology of the elevated part showed aggregates of intradermal nevus cells of normal morphological characteristics. Atypical and irregularly sized melanocytes were observed in the flat part, infiltrating the entire depth of the epidermis and the upper parts of the papillary dermis. The diagnosis of malignant melanoma developing from a dermal nevus was established (Breslow 0.4 mm, pT1A) (Figure 1, c). The second patient, a 71-year-old man, presented in 2018 with a pendular non pigmented intradermal nevus on middle part of the back. The left-hand lateral side of the intradermal nevus showed a brown to dark-brown spot which measured 12 mm (Figure 2, a). A central blue white veil, atypical pigment network, and dots and globules of various sizes and shapes were observed on dermoscopy (Figure 2, b). The base of the nevus showed an asymmetric pigmentation. Because the lesion was highly suspicious of melanoma, an urgent excision was indicated. The histopathology of the elevated part (dermal nevus) showed a regular maturation of the nest of nevus cells in the dermis. The histopathology of the dark-brown macule showed proliferation of atypical melanocytes with well-marked nucleoli throughout the epidermis with the infiltration of the suprabasal epidermal layers and papillary dermis. The lesion was classified as melanoma with a partial regression (Breslow 1.3 mm, pT2A), arising in association with an acquired intradermal nevus (Figure 2, c). Case reports with melanoma developed from a small congenital or acquired dermal nevus are extremely rare in the literature. In all published cases, histopathology revealed a melanoma component situated below or laterally, next to the merging dermal nevus (3) and in one case next to and above the dermal component (4), which is very similar to our cases. In both of our cases, melanoma presented an epidermal component with atypical, large melanocytes next to or above the typical and small intradermal melanocytes of the Unna nevus. Despite the fact that the reported statistical occurrence of malignant transformation of every individual nevus is very low in the elderly population (>60 years of age), 1 in 33,000 (5), we believe our two presented cases show a striking similarity in the melanoma manifesting in the vicinity of a previously existing lesion, indicating nevus-associated melanoma (NAM). This letter presents an interesting finding of two cases, with a form of melanoma (NAM) that is statistically very rare in older patients but occurred twice within the span of a year within the same town and was diagnosed in the same hospital. Intradermal nevi are most commonly considered to be benign skin lesions. However, previous research and our two cases shows that intradermal nevi are not immune to malignant alteration. Based on these results, we suggest a detailed clinical and dermoscopic evaluation of each skin lesion, including intradermal nevi. Flat melanocytic parts in the vicinity of intradermal nevi should always raise suspicion and warrant excision with histopathological evaluation of the lesion so as to allow timely response to any malignant alteration.

Clinicopathologic and genetic characterization of invasive melanoma with BRAF V600K mutation: A study of 16 cases.

BACKGROUND: The clinicopathologic and genetic features of cutaneous melanoma with a BRAF V600K mutation are not well-known. We aimed to evaluate these characteristics in comparison with those associated with BRAF V600E. METHODS: Real-time polymerase chain reaction (PCR) and/or the MassARRAY® system were used to detect BRAF V600K in 16 invasive melanomas and confirm BRAF V600E in another 60 cases. Immunohistochemistry and panel next-generation sequencing were used to evaluate protein expression and tumor mutation burden, respectively. RESULTS: The median age of melanoma patients harboring the BRAF V600K mutation (72.5 years) was higher than those with the BRAF V600E (58.5 years). The two groups also differed in sex (13/16 [81.3%] male in the V600K group vs. 23/60 [38.3%] in V600E) and in the frequency of scalp involvement (8/16 [50.0%] in V600K vs. 1/60 [1.6%] in V600E). The clinical appearance was similar to a superficial spreading melanoma. Histopathologically, non-nested lentiginous intraepidermal spread and subtle solar elastosis were observed. One patient (1/13, 7.7%) had a pre-existing intradermal nevus. Diffuse PRAME immunoexpression was seen in only one (14.3%) of seven tested cases. Loss of p16 expression was observed in all 12 cases (100%) analyzed. The tumor mutation burden was 8 and 6 mutations/Mb in the two tested cases. CONCLUSIONS: Melanoma carrying the BRAF V600K mutation showed the predominance on the scalp of elderly men, lentiginous intraepidermal growth, subtle solar elastosis, possible existence of intradermal nevus component, frequent loss of p16 immunoexpression, limited immunoreactivity for PRAME, and intermediate tumor mutation burden.

Concordance of reflectance confocal microscopy and gene expression profiling for melanocytic lesions with uncertain malignant potential: A case series.

For a small yet significant proportion of melanocytic lesions, histopathologic analysis may be unable to definitively evaluate malignant potential. These cases may signify a specific need for newer ancillary diagnostic technologies, including in vivo reflectance confocal microscopy (RCM) and gene expression profiling (GEP), both of which are highly sensitive in the diagnosis of melanoma. We report four cases of clinically suspicious melanocytic lesions that lacked definitive malignant features on histopathology and that were aided by use of RCM and GEP. Three of the four cases showed concordance between RCM and GEP in the diagnosis of melanoma. In one case, RCM was suggestive of melanoma; on the other hand, GEP and histopathology supported a final diagnosis of compound Spitz nevus. These cases support the role of RCM as a novel, non-invasive diagnostic tool to aid in the diagnosis of clinically suspicious melanocytic lesions with uncertain malignant potential, although RCM may have relatively lower accuracy for some atypical spitzoid lesions.

A rare cutis verticis gyrata secondary to cerebriform intradermal nevus: case report and literature review.

BACKGROUND: Cutis verticis gyrate (CVG) is a rare morphologic syndrome that presents with hypertrophy and folding of the scalp. CVG can be classified into three forms: primary essential, primary non-essential, and secondary. Cerebriform intradermal nevus (CIN) is a rare cause of secondary CVG. We are here to report a rare case of CVG with an underlying CIN and discuss the clinical course, treatment options, and critical screening guidelines for these patients. CASE PRESENTATION: A 25 year-old male patient presented with a chief complaint of generalized hair loss in the scalp parietaloccipital region for a duration of 1 year and the hair loss area was occasionally accompanied by mild itching. The hair loss started gradually and worsened over time. In addition, he had scalp skin folds resembling the ridge and furrow of the cerebral cortex in the parietaloccipital region since birth. Physical examination revealed hypertrophy and formation of folds in the parietal-occipital area, forming 5 to 6 furrows and ridges. The size of the cerebriform mass was about 12.0 cm × 8.5 cm, without other skin lesions. Diffuse non-scarring hair loss was distributed on the posterior-parietal scalp, mid-parietal scalp and superior-occipital scalp. The diseased tissue of the patient's parietaloccipital area was excised under general anesthesia. The postoperative pathological examination of the tissue excised showed that there were dense intradermal melanocytic nevus, so the patient was diagnosed with secondary CVG caused by CIN. At the 2 year follow-up, there were no obvious changes in the lesions. CONCLUSIONS: CIN must be differentiated from other conditions that manifest as CVG, including primary essential or non-essential CVG and secondary CVG caused by other reasons. Each CIN patient requires a specific decision of whether to excise the lesion surgically or follow a wait-and-see policy, depending on the patient's will and specific condition. Surgical treatment may be performed when there is an aesthetic demand. However, clinical observation and close follow-up is also a good treatment choice for patients with stable disease or mild symptoms.

Shave Excision Versus Elliptical Excision of Nonpigmented Intradermal Melanocytic Nevi: Comparative Assessment of Recurrence and Cosmetic Outcomes.

BACKGROUND: Nonpigmented intradermal melanocytic nevi (IMN) are benign lesions often removed for cosmetic reasons. There is no consensus as to the best technique for IMN excision. OBJECTIVE: To compare cosmetic outcomes and risk of recurrence after shave excision versus elliptical excision of IMN. MATERIALS AND METHODS: In this randomized clinical trial, patients underwent shave excision or elliptical excision with sutured closure of IMN of the face or back. Recurrence, patient satisfaction, cosmetic outcome, postoperative discomfort, scar size, discoloration, and presence of hypertrophic or keloid scars were evaluated at 3, 6, and 9 months. RESULTS: Overall, 145 nevi were removed from 45 patients (86.7% women, mean age 52.1 ± 12.5 years). The recurrence rate was 11.7%, occurring only after shave excision; 94.1% of recurrences were observed at 3-month follow-up. Shave excision was associated with less discomfort 48 hours after intervention but a greater likelihood of involved lateral and deep margins (p < .001). Scars were larger after elliptical excision and suture than after shave excision (p < .01). The mean patient satisfaction was higher in the shave excision group (p < .004). CONCLUSION: Shave excision of IMN is associated with higher rates of involved surgical margins and recurrence than elliptical excision but provides superior cosmesis and patient satisfaction.

Scalp expansion for giant cutis verticis gyrata secondary to cerebriform intradermal nevus.

Cutis verticis gyrata (CVG) is characterized by extensive formation of scalp skin that mirrors the folds of the cerebral gyri. Giant CVG secondary to cerebriform intradermal nevus (CIN) has been rarely reported, and its management mainly involves surgical excision. In certain cases of giant CVG, however, surgical excision is dilemmatic. This case report describes a giant CVG secondary to CIN that was successfully managed with scalp expansion and surgical excision. Previously published studies are also reviewed.

Dermoscopic patterns of intradermal naevi.

BACKGROUND: Intradermal naevi represent a benign histopathological variant of common melanocytic naevi. Studies describing dermoscopic criteria of dermal naevi are very limited. OBJECTIVES: To identify dermoscopic features of dermal naevi in order to facilitate differential diagnosis from malignant lesions. METHODS: A 15-year retrospective study was performed to evaluate the dermoscopic characteristics of 202 dermal naevi, histopathologically diagnosed through the analysis of digital dermoscopic images performed with polarised light dermoscopy. For each lesion, vascular pattern, pigment pattern and other dermoscopic clues were evaluated. RESULTS: 147 Unna naevi and 55 Miescher naevi were included in the study. Brown pigment (37.1%) was the pigment pattern most frequently observed in both Unna and Miescher naevi, followed by cobblestone pattern (30.6%) in Unna naevi and white areas (23.6%) and dotted/globule pattern (20%) in Miescher naevi. As regards the vascular patterns, the polymorphic one was the most frequently observed (34.6%). The combination between comma-shaped and arborising vessels was the most common among all naevi. CONCLUSIONS: Our study describes the dermoscopic features of dermal naevi that may help to differentiate them from malignant lesions such as basal cell carcinoma, amelanotic melanoma and Spitz naevi.

Osteonevus of Nanta: a case report in a combined melanocytic nevus

Abstract Secondary osteoma cutis is a phenomenon that may occur in several conditions. When it occurs in a melanocytic nevus it is named osteonevus of Nanta, an event considered uncommon and characterized by the presence of bone formation adjacent or interposed with melanocytic cells. There are reports of its occurrence in various melanocytic lesions, being more frequently associated with intradermal nevus. We report a case of osteonevus of Nanta in combined nevus, possibly the first description of this association.

Osteonevus of Nanta: a case report in a combined melanocytic nevus.

Secondary osteoma cutis is a phenomenon that may occur in several conditions. When it occurs in a melanocytic nevus it is named osteonevus of Nanta, an event considered uncommon and characterized by the presence of bone formation adjacent or interposed with melanocytic cells. There are reports of its occurrence in various melanocytic lesions, being more frequently associated with intradermal nevus. We report a case of osteonevus of Nanta in combined nevus, possibly the first description of this association.

Adult-onset porokeratotic eccrine ostial and dermal duct nevus:dermatoscopic findings and treatment with tazarotene.

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare dermatosis initially described as 'comedo nevus' and renamed 'PEODDN'; it has also been referred to as linear eccrine nevus with comedones, porokeratotic eccrine ostial and hair follicle nevus, and porokeratotic adnexal ostial nevus. PEODDN is usually present at birth or develops early in life. Rarely, PEODDN can develop in adults. The treatment of this puzzling condition is not standardized. We report herein a new case of adultonset PEODDN with dermatoscopic images. Our patient responded favorably to topical tazarotene.