Blue nevus-like and blue nevus-associated melanoma: a comprehensive review of the literature

Utility of next-generation sequencing in the diagnosis of metastatic melanoma: A case report

During routine dermatologic examination, a 77-year-old male was noted to have a firm blue subcutaneous nodule on his right lateral upper back. His past medical history included metastatic melanoma of unknown primary involving right and left axillary lymph nodes, treated with ipilimumab/nivolumab with complete response, and subsequent primary uveal melanoma. The subcutaneous nodule was located near his previous right axillary scar for metastatic melanoma. Excision of the nodule showed a plexiform neoplasm involving mid and deep dermis composed of spindle and epithelioid atypical cells admixed with numerous melanophages. Central necrosis was present. Immunohistochemical studies revealed the tumor cells to be diffusely positive for HMB45, with retained expression of BAP1 and p16. The tumor cells were negative for PRAME, nuclear expression of β-catenin, LEF1, and BRAF V600E. Molecular studies demonstrated BAP1 and GNA11 somatic mutations, a profile different from that exhibited by his prior melanoma. Collectively, these data were interpreted as a metastasis from uveal melanoma and not a recurrence of his metastatic likely cutaneous melanoma after complete response to immunotherapy. This case emphasizes the importance of molecular studies for definitive diagnosis in challenging clinical situations, especially when there is discordance among histopathological, immunohistochemical, and molecular studies. Integration of clinical, histopathological, and molecular features is warranted.

Oral Mucosal Lesions in Childhood

Childhood diseases are a continuous source of interest in all areas of general and dental medicine. Congenital, developmental, and hereditary diseases may either be present upon birth or appear in early childhood. Developmental anomalies, although often asymptomatic, may become grounds for different infections. Furthermore, they can indicate certain systemic disorders. Childhood age frequently brings about benign tumors and different types of traumatic lesions to the oral mucosa. Traumatic lesions can be caused by chemical, mechanical, or thermal injury. Mucocele and ranula are, by definition, traumatic injuries of the salivary glands or their ducts. Recurrent aphthous lesions are the most common type of ulcerations in childhood, and their etiology is considered multifactorial. Oral mucosal lesions in children require different treatment approaches depending on etiological factors and clinical presentation. Clinicians should have adequate knowledge of oral anatomy in order to diagnose and treat pathological conditions.

Uterine Cellular Blue Nevus Arising in Mullerian and Pelvic Dendritic Melanocytosis: Case Report of a Rare Phenomenon to Be Distinguished From Uterine Melanoma

A 37-yr-old woman presented to the gynecology clinic with abnormal uterine bleeding in the setting of known, large uterine fibroids. Preoperative endometrial biopsy identified atypical melanocytic cells concerning for uterine melanoma. Care was transferred to the gynecologic oncology service for hysterectomy. Intraoperative findings included macular, blue-black pigmentation of the peritoneum of the bladder and cervix, which was resected and sent for frozen section, confirming melanocytic neoplasia. The hysterectomy revealed multiple tan leiomyomas up to 12 cm, and a distinct 3 cm black, incompletely circumscribed mass in the endomyometrium composed of bland spindled cells with delicate melanin granules. The tumor cells were positive for Sox-10, BAP1, and Mart-1 (Melan-A) and negative for PRAME, PD-L1, and BRAFV600E by immunostains. Microscopic elements of similar melanocytes and melanophages were found in the cervix and bladder peritoneum. Molecular analysis of the uterine tumor identified a GNA11 mutation but no TERT or BAP1 mutation. The uterine melanocytic tumor has characteristic findings of a cellular blue nevus arising in association with dendritic melanocytosis of Mullerian and pelvic tissues, a rarely seen benign phenomenon that should be distinguished from malignant melanoma of the upper genital tract.

Histopathologic classification and prognostic factors of melanoma: a 2021 update

Despite the rapid recent advances in molecular analysis of tumors, which allow large-scale and high-resolution genomics, the "gold standard" for melanoma diagnosis continues to be histopathology, in conjunction with clinical characteristics and sometimes with important support of immunohistochemistry. Observations, where postulated that cutaneous melanomas may arise through two distinct pathways, discoveries such as that BRAF^V600E mutations were mostly common in melanomas on sun-exposed skin with little solar elastosis and seminal works for melanoma progression and evolution set the groundwork for the new WHO Classification of Melanoma: a classification of melanoma that not only encompasses histologic but also clinical, epidemiologic, and genetic characteristics. The melanomas were divided into those etiologically related to sun exposure and those that are not, based on their mutational signatures, anatomic site, and epidemiology. On the basis of degree of associated solar elastosis melanomas on the sun exposed skin were further divided by the histopathologic degree of cumulative solar damage (CSD) of the surrounding skin, into low and high CSD. On the low-CSD group of melanomas are included superficial spreading melanomas, while the high-CSD melanomas encompasses lentigo maligna and desmoplastic melanomas. The "non-CSD" classification includes acral melanomas, some melanomas in congenital nevi, melanomas in blue nevi, Spitz melanomas, mucosal melanomas, and uveal melanomas. Nodular and nevoid melanoma may occur in any pathway. A group of intermediate tumors termed melanocytoma is proposed for tumors that in addition to mutations that activate the MAPK pathway, harbor multiple driver mutations, and they are either low-grade or high-grade, to indicate that they may carry a higher risk of malignant transformation. In this review a summary of the most recent WHO classification of melanoma is provided. A short analysis of essential histopathologic prognostic parameters is also provided. The new classification of melanoma discriminates distinct types of melanoma based on their clinicopathologic, and genomic characteristics. Undoubtedly, melanoma research will continue to evolve as new clinical, pathological, molecular data accumulates. The challenge of the forthcoming years is to better characterize the intermediate category of melanocytic lesions.

Giant Congenital Blue Nevus Presenting as Cutis Verticis Gyrata: A Case Report and Review of the Literature

OBJECTIVES

Cerebriform intradermal nevus and giant congenital blue nevi are rarely reported melanocytic nevi with clinical and histopathologic similarities. Both are known to produce cutis verticis gyrata. We report a significantly large occipital scalp congenital blue nevus with secondary cutis verticis gyrata. The aim of this report is to increase clinical awareness of this entity, highlight histopathologic and mutational features of cerebriform intradermal nevi and giant congenital blue nevi, and stress the importance of clinicopathologic correlation for diagnosis.

METHODS

Case report and review of the literature.

RESULTS

A 20-year-old Asian male presented with a long-standing, large (20 cm × 30 cm), exophytic tumor at the occipital scalp and posterior neck. The skin overlying the lesion was arranged in thick folds resembling the surface of the brain, devoid of hair follicles, and discolored by salt-and-pepper pattern hyperpigmentation. After correlating the clinical and histopathologic findings, we diagnosed giant congenital blue nevus with secondary cutis verticis gyrata. Staged surgical excision was performed with subsequent treatment for hypertrophic scarring and occipital alopecia.

CONCLUSIONS

Cerebriform intradermal nevus and giant congenital blue nevus have overlapping histologic and clinical features. Head and neck surgeons should be aware that nomenclature of these tumors is subjective and often imprecise. Diagnosis requires correlation of clinical findings, patient history, and histopathology. Surgical excision is advised due to rare malignant transformation potential.

Atypical Cellular Blue Nevus With Necrosis Mimicking Melanoma Ex-Blue Nevus

ABSTRACT

Histologic distinction between melanoma ex-blue nevus and cellular blue nevus (CBN) can often be difficult, but features supporting melanoma include infiltrative growth pattern, frequent mitoses, cytologic atypia and pleomorphism, cell crowding, and tumor necrosis. Unfortunately, these features are not constantly dependable and frequently borderline lesions exist, so-called atypical CBN, which lack explicit malignant features. Furthermore, some CBN and atypical CBN show an assortment of features, which may lead to their misdiagnosis as melanoma, but to date necrosis is generally absent. We present an unusual case of an atypical cellular blue nevus with extensive necrosis mimicking melanoma ex-blue nevus.

Nevus-associated melanoma: facts and controversies

Nevus-associated melanoma (NAM) is defined on histopathological basis by the coexistence of melanoma and nevus components. Melanomas developing on pre-existing congenital or acquired nevi are usually of the superficial spreading subtype and harbor the BRAFV600E mutation. NAM accounts for almost one-third of melanoma cases As compared to de novo melanoma, NAM develops on younger patients, is more frequently located on the trunk, and is associated with a high nevus count, light eye color and history of frequent sunburns. NAM has been regarded as a model to investigate melanoma origin. Molecular analysis defining the mutation profile of NAM's nevus and melanoma components supported the existence of two pathways of melanoma development, the first not involving clinically visible precursors, the second involving melanocytic nevi as precursors. Concerning diagnosis, dermatoscopy may identify nevus and melanoma components when located side-by-side, but no specific criteria have been described when superimposed. In-vivo reflectance confocal microscopy significantly enhances the recognition of NAM by allowing the detection of nevus remnants when superficially located. Regarding prognosis, NAM is generally thinner and more frequently in-situ than de-novo melanoma. Furthermore, studies reporting survival analysis demonstrated a trend towards better overall, distant-metastasis-free and recurrence-free survival. Although a clinical, phenotypic and molecular profile of NAM has been defined, controversies still exist. In the current review, we widely report and discuss facts and controversies on NAM.

Intra-Scleral Blue Nevus Arising within Oculodermal Melanocytosis: Melanoma or Not?

We report a 61-year-old female who presented to our service with recent growth of a thickened, pigmented, sub-conjunctival lesion within an area of ocular melanocytosis in her left eye. Lamellar sclerectomy was performed. Histopathological assessment revealed a localized melanocytic proliferation with features of blue nevus arising within the area of ocular melanocytosis. There was a small zone of cells showing cytological atypia and expansion of the scleral stroma. We believe this case to be the first report of intrascleral blue nevus arising within an area of ocular melanocytosis. Given the cytological atypia, the blue nevus may perhaps represent an intermediate stage within a progression from ocular melanocytosis towards melanoma. Patients with oculodermal melanocytosis merit regular long-term surveillance for early detection of melanoma, not only in the uvea, but also in the orbit and potentially the ocular surface.

The 2018 World Health Organization Classification of Cutaneous, Mucosal, and Uveal Melanoma: Detailed Analysis of 9 Distinct Subtypes Defined by Their Evolutionary Pathway

CONTEXT.—

There have been major advances in the understanding of melanoma since the last revision of the World Health Organization (WHO) classification in 2006.

OBJECTIVE.—

To discuss development of the 9 distinct types of melanoma and distinguishing them by their epidemiology, clinical and histologic morphology, and genomic characteristics. Each melanoma subtype is placed at the end of an evolutionary pathway that is rooted in its respective precursor, wherever appropriate and feasible, based on currently known data. Each precursor has a variable risk of progression culminating in its fully evolved, invasive melanoma.

DATA SOURCES.—

This review is based on the "Melanocytic Tumours" section of the 4th edition of the WHO Classification of Skin Tumours, published in 2018.

CONCLUSIONS.—

Melanomas were divided into those etiologically related to sun exposure and those that are not, as determined by their mutational signatures, anatomic site, and epidemiology. Melanomas on the sun-exposed skin were further divided by the histopathologic degree of cumulative solar damage (CSD) of the surrounding skin, into low and high CSD, on the basis of degree of associated solar elastosis. Low-CSD melanomas include superficial spreading melanomas and high-CSD melanomas incorporate lentigo maligna and desmoplastic melanomas. The "nonsolar" category includes acral melanomas, some melanomas in congenital nevi, melanomas in blue nevi, Spitz melanomas, mucosal melanomas, and uveal melanomas. The general term melanocytoma is proposed to encompass "intermediate" tumors that have an increased (though still low) probability of disease progression to melanoma.

Diagnostic accuracy and safety of short-term teledermoscopic monitoring of atypical melanocytic lesions

BACKGROUND

Short-term dermoscopic monitoring (STDM) of atypical melanocytic lesions (AML) after 3.0-4.5 months can be used to detect featureless melanomas without performing countless unnecessary excisions of nevi. Recently, short-term teledermoscopic monitoring (STTM) was incorporated into the STDM clinical routine at Sahlgrenska University Hospital in Gothenburg, Sweden. Follow-up images for STTM were taken by an assistant nurse with subsequent teledermoscopic assessment by a dermatologist.

OBJECTIVES

The purpose of this study was to evaluate the diagnostic accuracy and safety of STTM.

METHODS

In this retrospective observational study, data from electronic health records of patients with teledermoscopically monitored AMLs were explored. The number of changed and excised AMLs and their histopathological diagnoses were recorded. The excised AMLs were categorized into three subgroups according to when they changed and were excised: (i) following STTM, (ii) after planned long-term follow-up or (iii) after unplanned long-term follow-up.

RESULTS

A total of 686 patients with 883 AMLs were monitored with STTM. Sixty-two AMLs (7.0%) were excised following STTM, 14 (1.6%) after planned long-term follow-up and 10 (1,1%) after unplanned long-term follow-up. Twenty-one melanomas were detected using STTM, three after planned long-term follow-up and three after unplanned long-term follow-up. All melanomas were in situ (n = 20) or thin and non-ulcerated (n = 7; median Breslow thickness 0.4 mm, range 0.3-0.8 mm). The sensitivity for the diagnosis of melanoma by means of STTM with the option of additional planned follow-up was 88.9%, and the specificity was 93.9%. The number of AMLs needed to monitor in order to detect one melanoma with the STTM routine was 32.7, and the number needed to excise was 3.2.

CONCLUSIONS

STTM of AMLs was safe and allowed for high diagnostic accuracy. All detected melanomas were in situ or thin and non-ulcerated. Furthermore, a considerable number of unnecessary excisions were spared.