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.

Dermoscopic Features of Twin Melanomas of the Lower Leg: A Case Report.

Multiple primary malignancies, including melanoma, usually present singly over time rather than simultaneously. Hovewer, approximatelly one third of the patients develop multiple primary melanomas. We present a case of a 57-year-old woman, with two grossly suspicious, unevenly pigmented lesions on her left lower leg measuring up to 8 and 11 mm. Dermoscopy of both lesions showed similar findings with complete asimmetry of colour and structure. More than four colours including milky red and accumulation of pigment at 1 o'clock were observed in the smaller lesion. Dermoscopy of the largest lesion showed more than 3 colours, milky-red areas, and a slight blue-white veil. Histopathology of both lesions revealed melanoma. Although uncommon, multiple primary melanomas do appear. Careful dermoscopical evaluation of all lesions is mandatory in order to not miss such cases.

Peritumoral Clefting and Expression of MMP-2 and MMP-9 in Basal Cell Carcinoma of the Skin.

BACKGROUND/AIM: Peritumoral clefting is one of the main histologic features of basal cell carcinoma of the skin (BCC). The aim of the study was to analyze the expression of MMP-2 and MMP-9 both in cells of basal cell carcinoma and in the adjacent stroma and to correlate the findings of immunohistochemical analysis with the presence of peritumoral clefting. PATIENTS AND METHODS: The study was made on archival material comprising 48 cases of BCC. These were scanned for the presence of peritumoral clefts. The results of immunohistochemical staining for MMP-2 and MMP-9 were determined semiquantitatively using immunohistochemical staining index (ISI). RESULTS: Peritumoral retractions were found in 40 BCC cases. Positive immunohistochemical reaction for MMP-2 in tumor cells was found in 47 cases and in all cases in the adjacent stroma. Positive immunostaining for MMP-9 in BCC tumor cells was observed in 37 cases and in all cases in the adjacent stroma. There was no statistically significant association between peritumoral retractions and expression of MMPs. A statistically significant correlation was found in the expression of both MMP-2 and MMP-9 between the tumor and the stroma. CONCLUSION: Tumor cells elaborate MMP-2 and -9, but they also produce some other factors that may induce production of MMPs in adjacent stromal cells. The role of MMPs in the development of peritumoral clefts could not be confirmed.

Folliculotropic mycosis fungoides with follicular mucinosis--case report.

Reports on clinical and histologic follicular alterations in patients previously diagnosed with mycosis fungoides (MF) or at the time of MF diagnosis are rare. The clinical and histologic criteria to distinguish MF associated with follicular mucinosis from follicular MF are a matter of debate. A patient is described with advanced clinical and histologic alterations predominated by follicular lesions and presence of mucin. In the early stage of the disease, folliculotropism was clinically and histologically present but less pronounced than epidermotropism and classic plaque-like lesions. The patient died four years after the diagnosis. As the term 'folliculotropic' describes a particular histopathologic finding, we consider it correct to use the term "folliculotropic MF" to denote atypical lymphocyte folliculotropism in the absence or presence of mild epidermotropism, presence of mucin, or no evidence for intrafollicular mucin. Folliculotropic MF seems to represent a specific clinicopathologic entity which may have a poorer prognosis than classic MF.

Nevus comedonicus--case report and review of therapeutical approach.

Nevus comedonicus is uncommon abnormality of pilosebaceous unit, clinically characterized as confluent clusters of dilated follicular orifices plugged with pigmented keratinous material that resembles open comedones. It is suggested that nevus comedonicus is an uncommon variant of adnexal hamartoma, which clinically appears as linear group of open comedones. Since Kofmann's description of nevus comedonicus in 1895, there have been reports of this rare cutaneous disorder associated with developmental anomalies. We present a case of a 19-year-old woman with numerous 1-3 mm size darkly pigmented, keratic plugs clustered in linear unilateral patches on left abdominal part. Our treatment consisted of the avoidance of the formulations containing nickel sulfate and carba mixture, daily local application of tretinoin 0.1% gel and corticosteroid ointment (momethasone furoate). After 4 weeks of local therapy cosmetic result was evident. The slight resolution of keratin plugs could also be seen. Two months after the treatment, there were no visible skin exacerbations.