Rapid perinatal growth mimicking malignant transformation in a giant congenital melanocytic nevus

[Early-onset melanoma (congenital, neonatal, infantile): A systematic review of literature cases]

INTRODUCTION

Neonatal and infantile malignant melanoma is rare. It may be difficult to diagnose and often carries a poor prognosis.

MATERIAL AND METHODS

We decided to review the data on congenital, neonatal and infantile malignant melanomas in order to understand their presentation (clinical, histological, molecular), diagnosis, management and outcomes. We performed a literature search of all cases of early-onset melanoma published in PubMed from its inception to March 2019 using the following keywords: "malignant melanoma" OR "melanoma" OR "pigmented nevus" OR "malignant pigmented" AND "infantile" OR "congenital" OR "children" OR "childhood" OR "infancy" OR "neonatal". Congenital melanoma associated with maternal-foetal transmission was not included in the study.

RESULTS

Sixty-five articles were selected and 85 cases were included in the study. Most patients were male (sex ratio: 1.6). The average age at diagnosis was 5.5 months (minimum-maximum: 0-24 months). The main site reported for congenital melanoma was the head-and-neck area and for neonatal and infantile melanoma the trunk. Half of all patients had a metastatic disease at the time of diagnosis. In metastatic cases, the prognosis was poor with the exception of patients undergoing complete excision of the tumour and metastases. The main treatment for cutaneous melanomas and operable metastasis was surgery, and secondarily, chemotherapy/immunotherapy.

CONCLUSION

Neonatal and infantile malignant melanoma are rarely reported and not well-documented. It is necessary to collect additional cases to improve our knowledge of this rare disease.

Mass Spectrometry Imaging Can Distinguish on a Proteomic Level Between Proliferative Nodules Within a Benign Congenital Nevus and Malignant Melanoma

Histopathological interpretation of proliferative nodules occurring in association with congenital melanocytic nevi can be very challenging due to their similarities with congenital malignant melanoma and malignant melanoma arising in association with congenital nevi. We hereby report a diagnostically challenging case of congenital melanocytic nevus with proliferative nodules and ulcerations, which was originally misdiagnosed as congenital malignant melanoma. Subsequent histopathological examination in consultation by one of the authors (R.L.) and mass spectrometry imaging analysis rendered a diagnosis of congenital melanocytic nevus with proliferative nodules. In this case, mass spectrometry imaging, a novel method capable of distinguishing benign from malignant melanocytic lesions on a proteomic level, was instrumental in making the diagnosis of a benign nevus. We emphasize the importance of this method as an ancillary tool in the diagnosis of difficult melanocytic lesions.

Late-onset bulky naevocytoma of the perineum masquerading as a malignant melanoma

Bulky naevocytoma of the perineum is a very rare variant of giant congenital melanocytic naevus (GCMN). It presents as a bulky naevocytic tumour in the perineal region with characteristic histological findings, such as extensive areas with a neural appearance called 'lames foliacees', formation of a pseudofollicular structure and extension of naevus cells between collagen bundles in a row called 'Indian-file' pattern. We report a case of late-onset bulky naevocytoma of the perineum in a 13-year-old girl. The patient presented with two bulky, pedunculated, heavily pigmented masses in the vulvar area that developed in a pre-existing GCMN lesion, which began around puberty and caused severe gait disturbance. Given the possibility of malignant transformation, we conducted staged reduction surgery of the tumour masses, which were found to be intradermal naevi without evidence of malignancy. The patient's gait disturbance improved markedly after surgery.

Giant congenital melanocytic naevus with proliferative nodules mimicking congenital malignant melanoma: a case report and review of the literature of congenital melanoma

Congenital malignant melanoma (CMM) is a rare condition that is defined as malignant melanoma recognized at birth. CMM may develop in utero in one of three ways: (1) transmission by metastasis through the placenta from a mother with melanoma; (2) primary melanoma arising within a giant congenital melanocytic naevus (GCMN); (3) primary de novo cutaneous CMM arising in utero. CMM can be confused clinically and histologically with benign proliferative melanocytic lesions such as giant congenital nevi. We describe the case of a patient presenting a GCMN with proliferative nodules, clinically and dermoscopically resembling a CMM, demonstrating the importance of caution in making a diagnosis of MM and highlighting the possibility that benign lesions as GCMN can mimic a malignant melanoma in this age group.

Congenital melanocytic nevi: where are we now? Part I. Clinical presentation, epidemiology, pathogenesis, histology, malignant transformation, and neurocutaneous melanosis

Congenital melanocytic nevi (CMN) are present at birth or arise during the first few weeks of life. They are quite common, may have a heritable component, and can present with marked differences in size, shape, color, and location. Histologic and dermatoscopic findings may help suggest the diagnosis, but they are not entirely specific. CMN are categorized based on size, and larger lesions can have a significant psychosocial impact and other complications. They are associated with a variety of dermatologic lesions, ranging from benign to malignant. The risk of malignant transformation varies, with larger CMN carrying a significantly higher risk of malignant melanoma (MM), although with an absolute risk that is lower than is commonly believed. They may also be associated with neuromelanosis, which may be of greater concern than cutaneous MM. The information presented herein aims to help dermatologists determine when it is prudent to obtain a biopsy specimen or excise these lesions, to obtain radiographic imaging, and to involve other specialists (eg, psychiatrists and neurologists) in the patient's care.

Proliferative nodules in a giant congenital melanocytic nevus-case report and review of the literature

Malignant transformation of giant congenital nevi (GCN) is very rare, but may already occur in childhood. Benign proliferative nodules in GCN may clinically and histologically mimic a malignant melanoma. We report a newborn infant with large proliferative nodules and multiple satellite nevi in a GCN of the bathing suit type. The diagnosis in our patient was based on the smooth transition of the pre-existing lesion and the nodule, the absence of strong atypical nuclei, the atypical mitotic figures, the ascension of melanocytes in the epidermis and the absence of necrosis. A review of the literature showed that the clinical and the histological features of benign (proliferative) nodules are variable. The awareness and the identification of this entity by clinicians and pathologist are imperative to prevent diagnostic errors.

Melanocytic nevi simulant of melanoma with medicolegal relevance

A group of melanocytic benign nevi are prone to be misdiagnosed as nodular or superficial spreading melanoma. This review illustrates the most frequent forms of these nevi in direct comparison with their malignant morphologic counterparts. The nevi are: hyper-cellular form of common nevus to be distinguished from nevoid melanoma, Spitz nevus (vs spitzoid melanoma), Reed nevus (vs melanoma with features of Reed nevus), cellular atypical blue nevus (vs melanoma on blue nevus), acral nevus (vs acral melanoma), Clark dysplastic nevus (vs superficial spreading melanoma), desmoplastic nevi (vs desmoplastic melanoma), benign proliferative nodules in congenital nevi (vs melanoma on congenital nevi), epithelioid blue nevus (vs animal type melanoma) and regressed nevus (vs regressed melanoma). For each single 'pair' of morphological look-alikes, a specific set of morphological, immunohistochemical and genetic criteria is provided.

Cutaneous ganglioneuroma within a giant congenital nevus

Cutaneous ganglioneuroma has only occasionally been reported in the literature. Cutaneous ganglioneuroma is seen even more rarely in association with a giant congenital nevus. Differential diagnosis includes malignancies, especially melanoma and metastatic neuroblastoma. It is essential to rule out malignancy in a solid lesion within a congenital nevus. The present report is possibly the first relating ganglioneuroma and a congenital nevus to a cervical mass detected during routine prenatal ultrasound.

Two case reports of rare fetal tumors: an indication for surface rendering?

Fetal tumors are rare and can be difficult to diagnose in utero. This report describes one case of an extrarenal rhabdoid tumor and one case of a giant congenital melanocytic nevus. Both presented with moderate polyhydramnios and were prenatally detected at 31 weeks of gestation with two-dimensional ultrasound. The application of the surface mode of three-dimensional ultrasound improved the visualization of these tumors especially for the parents and the multidisciplinary team. Three-dimensional sonography proved to be a valuable addition to the prenatal armamentarium for the evaluation of these fetal tumors although it is not mandatory for their assessment and clinical management.

A newborn with nodular ulcerated lesion on a giant congenital nevus

The proliferative nodule is a lesion that develops within a congenital nevus. It is usually small (less than 5 mm), sometimes multiple, with a slow growth rate, and has a black or dark brown, smooth, shiny surface. It usually involutes spontaneously. We report a newborn infant who, at birth, had a giant congenital nevus with a nodular, ulcerative, hemorrhagic lesion within it. Physical and neurologic examinations were normal. Radiologic studies at birth and subsequently were normal. A fragment of the lesion was biopsied and histologic findings were compatible with a diagnosis of proliferative nodule in a giant congenital nevus. The rest of the nodule regressed spontaneously after 4 months.

Benign melanocytic proliferative nodule within a congenital naevus

A neonate presented with a deeply pigmented papule within a medium-sized congenital naevus. Histologically, this proved to be a benign proliferative nodule in a congenital naevus. This case is presented to highlight the occurrence of this lesion, the main differential of which is the rare entity of true congenital melanoma.

Adnexal-centered giant congenital melanocyte nevus with extensive ganglioneuromatous component and trisomy 7

Adequate interpretation of clinical and histopathologic features of giant congenital melanocytic nevus (GCMN) in newborns is a continued challenge. A GCMN with three large nodules and three polypoid exophytic tumors presented in the dorsum of a female full-term newborn, the borders exhibiting a spotted grouped pattern. Microscopic examination revealed a peculiar adnexal-centered (eccrine sweat gland ducts, acrosiringia, and hair infundibula) compound nevus expressing pagetoid intraepidermal spreading of epithelioid melanocytes. The nodules represented an extensive ganglioneuromatous component. The neurons and their neuropil were positive for neuron-specific enolase, S-100, synaptophysin, tyrosine hydroxilase, and PGP 9.5. In addition to these components, a poorly differentiated, fusiform, low-mitotic rate population of cells undergoing epithelioid differentiation (and probably neuronal differentiation) with nodular arrangement was also present in the polypoid tumors and deeper parts of the nevus, in part intermixed with the neurons. These cells were vimentin positive but S-100 negative. FISH studies revealed these cells to express three signals for the centromeric probe for chromosome 7 whereas the neuronal component showed just two. Adnexal-centered arrangement of melanocytes has not been emphasized in GCMN. Ganglioneuromatous differentiation has been rarely reported in this condition. Trisomy 7 in GCMN has been reported only once previously.

Nevus cells and special nevomelanocytic lesions in children

Nevomelanocytic lesions in children represent a wide spectrum of proliferative neurocristopathies, ranging from the common small and benign congenital nevi to the garment-type congenital lesions. Included in this spectrum are some rare entities like neurocutaneous melanocytosis, malignant melanoma simulants, and special variants of congenital pigmented nevi. Here, we analyze some tissue culture characteristics of nevomelanocytic cells from giant and small congenital nevi, neurocutaneous melanocytosis, and a rare variant of nevus named "bulky nevocytoma." Correlations with their histological, immunohistochemical, and ultrastructural features are addressed.

Blue nevus: classical types and new related entities. A differential diagnostic review

Blue nevus is an uncommon pigmented lesion of dermal melanocytes. By convention, two well defined histologic variants, designated as "common" and "cellular", have been recognised. In the last few years, these lesions have attracted much attention due to the recognition of news entities and to its confusion with malignant melanoma. In the present review, we point out the more striking features of new related entities (combined nevus, deep penetrating nevus, compound blue nevus) and establish the differential diagnosis with conflictive lesions such as atypical blue nevus, locally aggressive blue nevus, congenital giant melanocytic nevus with nodular growth and melanocytic dermal tumor of unpredictable outcome. We also review the concept of malignant blue nevus and the significance of lymph node metastases. The blue nevus is an uncommon pigmented lesion consisting of dermal melanocytes that can appear in diverse forms: dendritic, spindle-shaped, oval-shaped, or polyhedral. Although it usually occurs in skin, it has been reported in other locations, such as oral mucosa, sclera, uterine cervix, vagina, prostate, spermatic cord, pulmonary hilus, orbit, conjunctiva, maxillary sinus, breast, and lymph nodes 3,8,42,49. Generally, it occurs in adults as a single, acquired, intensely pigmented lesion, although familial and multiple nevi have been reported 7,39. By convention, there are two well-defined histologic variants, designated as "common" and "cellular", but lesions often manifest intermediate features. In the last few years, blue nevus has attracted much attention due to the recognition of new (clinical and histologic) entities and to its confusion with malignant melanoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Nevomelanocytic proliferations in the central nervous system of children

BACKGROUND

Melanocytic proliferations affecting the central nervous system (CNS) of children may be classified as meningeal melanocytosis, primary melanoma, or metastatic melanoma. Meningeal melanocytosis often is associated with giant congenital pigmented nevi (preferentially involving the midline, the head and neck) representing the lethal condition neurocutaneous melanocytosis. Primary or metastatic melanomas, although extremely rare in children, can occur in the brain and its coverings and are associated with a poor prognosis.

METHODS

A retrospective study of five patients with nevomelanocytic proliferations of the CNS was performed.

RESULTS

There was characteristic enhancement in the magnetic resonance imaging (MRI) with gadolinium contrast, abnormal cerebral spinal fluid (CSF) cytology with neoplastic cells showing cytoplasmic prolongations, and nevomelanocytic proliferation in the meninges expressing HMB45 positivity and exhibiting ultrastructural features of melanocytes.

CONCLUSIONS

Because of the rarity of these lesions, awareness of their existence is crucial for their recognition. Clinical, radiologic, and cytologic, correlation may allow an opportune diagnosis, which would allow avoidance of brain biopsy. Melanin production is not restricted to melanocytic neoplasms, and other CNS tumoral lesions occasionally may feature melanin as part of their histologic findings.

Giant congenital nevi: a conceptualization of patterns

Patterns in giant congenital nevi are classified as to extent of cellular involvement of the reticular dermis and by the quality of the fibrous matrix. In addition, classifications are influenced by degrees of cellular atypia. Two general categories are defined. In one, the phenomena are relatively independent of those operative at the dermal-epidermal interface. The lesions are characterized as dermal congenital tumorous dysplasias-blastomas. They are subdivided into major, intermediate, and minor categories and into mature and immature variants. In these variants, disparate populations in the patterns of nodules and plaques (lumpy-bumpy variants) qualify as dermal variants of minimal deviation melanoma as seen in the setting of giant congenital nevi. The respective melanomas in this category are small-cell malignant neoplasms (melanoblastomas of infancy and childhood). In a second category in the clinical setting of giant congenital nevus, rare childhood and some adult melanomas of a more common histologic type evolve from lentiginous and junctional components in patterns that recapitulate those of the dysplastic nevus syndrome. The suspicious areas in all categories are evaluated by the same clinical criteria. In the dysplasia-blastoma category, enlarging nodules must be biopsied. The criteria for the evaluation of lesions in the dysplastic nevus syndrome and in the category of minimal deviation melanoma have application to the unstable regions in giant congenital nevi.

Malignant melanoma in childhood: a clinicopathologic study of 13 cases and comparison with Spitz nevi

The clinical and histological features of 13 malignant melanomas in children less than 13 years of age in New South Wales, Australia, were compared with those in a control group of children with 15 Spitz nevi, 4 of which were considered atypical, and 2 unusual compound nevocellular nevi. Six of the controls had been previously diagnosed histologically as malignant melanoma. The objective observations made by one or more histopathologists experienced in reporting melanocytic lesions, and the clinical details, mainly from the Sydney Melanoma Unit files, were entered on a detailed protocol. Evaluation was assisted by the use of SPSS-X software on a mainframe VAX computer. Six of the 13 children with malignant melanoma died with their disease. The most frequent clinical features found in the malignant melanomas were bleeding, ulceration, itching, and black or variegated color. Recent enlargement and darkening were noted in the majority of both the malignant melanomas and the Spitz nevi. Histological features favoring malignancy in this series were mitoses within 0.25 mm of the dermal margin of the melanoma, a dermal mitotic rate exceeding 2/mm2, ulceration, surface exudate, large pigment granules, and clear-cell differentiation. The median thickness of the malignant melanomas was 1.3 mm but in the 4 children who died with melanoma the median thickness was 2.9 mm. Absence of mitoses, predominance of spindle cells, and diffuse maturation favored Spitz nevus. The median thickness of the Spitz nevi was 0.7 mm.

Bulky naevocytoma of the perineum: a singular variant of congenital giant pigmented naevus

We describe two instances of a previously unrecognized variant of congenital giant pigmented naevus (GPN), presenting as a bulky naevocytic tumour in the perineal region. In both cases the lesion was present at birth and attained massive dimensions. In addition to the characteristic histological patterns found in GPN, which included extensive areas with a neural appearance, these tumours presented an uncommon tendency to form pseudo-follicular structures lined by naevus cells. No features suggestive of malignant transformation were found. Because GPN may associate with an underlying malignancy, accurate diagnosis of this lesion is important in clinical practice.