The spectrum of spitzoid tumours: A clinical study

This study explores the relationship between different types of spitzoid tumours, spindle cell naevus of Reed and spitzoid melanomas. Clinical and histopathological data were retrospectively reviewed from our hospital database in Cambridge from January 2006 to July 2009. Clinical images, where available, were recorded. Search headings from our pathology database included ‘spitzoid tumours’, ‘Spitz naevi’, ‘atypical spitzoid tumours’, spitzoid tumours of uncertain malignant potential (‘STUMP’), ‘spindle cell naevus of Reed’ and ‘spitzoid melanomas’. The total number of spitzoid tumours was 118 comprising Spitz naevi (72), atypical spitzoid tumours (30), spitzoid melanomas (eight), and other naevi with spitzoid features (eight). In total, 60% of Spitz naevi were diagnosed clinically and 50% reported a history of change with spitzoid melanoma, compared with 32% with Spitz naevi. In all, 60% of Spitz naevi and atypical spitzoid tumours were pigmented in contrast with spitzoid melanomas (83%). Variegated pigmentation was found in 20% of Spitz naevi and atypical spitzoid tumours, however, no spitzoid melanomas had mixed pigmentation. There were 30 atypical spitzoid tumours (9 M : 21 F); 16 occurred on the lower limbs, peaking in the 20–30‐years age group. There were eight patients with spitzoid melanomas with a 7:1 F : M ratio, 50% of which were diagnosed clinically. Of the 34 spindle cell naevus of Reed (10 M : 24 F), 31 were misdiagnosed, most commonly as melanoma. Reed naevi peaked in the 30–40 year age group and on the upper limbs and lower limbs in the 20–30‐years age group. In summary, age and sex appeared helpful in distinguishing benign from malignant spitzoid tumours, however history was less discriminatory. Spitzoid melanomas, most of which were pigmented occurred more commonly in females. Atypical spitzoid tumours were more common in females and pathologists favoured malignancy in this group beyond 20 years of age.     

BRAF, NRAS and HRAS mutations in spitzoid tumours and their possible pathogenetic significance

Background The relationships between so‐called spitzoid tumours have proven difficult to understand. Objectives To address three questions: does spitzoid tumour morphological similarity reflect molecular similarity? Does Spitz naevus progress into spitzoid melanoma? Are ambiguous spitzoid tumours genuine entities? Methods BRAF, NRAS and HRAS mutations were analysed using single‐strand conformational polymorphism analysis and sequencing. Results Both Spitz naevi and spitzoid melanoma had a lower combined BRAF and NRAS mutation frequency compared with common acquired naevi (P = 0·0001) and common forms of melanoma (P = 0·0072), respectively. To look for evidence of progression from Spitz naevi to spitzoid melanoma, HRAS was analysed in 21 spitzoid melanomas, with no mutations identified. The binomial probability of this was 0·03 based on an assumption of a 15% mutation frequency in Spitz naevi with unbiased progression. Under these assumptions, HRAS mutations must be rare/absent in spitzoid melanoma. Thus, Spitz naevi seem unlikely to progress into spitzoid melanoma, implying that ambiguous spitzoid tumours cannot be intermediate degrees of progression. In addition, the data suggest that HRAS mutation is a potential marker of benign behaviour, in support of which none of three HRAS mutant spitzoid cases metastasized. Conclusions First, the morphological similarity of spitzoid tumours reflects an underlying molecular similarity, namely a relative lack of dependence on BRAF/NRAS mutations. Second, Spitz naevi do not appear to progress into spitzoid melanoma, and consequently ambiguous spitzoid tumours are likely to be unclassifiable Spitz naevi or spitzoid melanoma rather than genuine entities. Third, HRAS mutation may be a marker of Spitz naevus, raising the possibility that other molecular markers for discriminating Spitz naevi from spitzoid melanoma can be discovered.     

Genetic and epigenetic alterations in the differential diagnosis of malignant melanoma and spitzoid lesion

BACKGROUND: The histopathological differentiation of malignant melanoma and Spitz naevus often presents diagnostic problems. OBJECTIVES: We aimed to find out applicable diagnostic parameters other than routine pathology. METHODS: The cases included conventional melanomas and Spitz naevi as well as atypical spitzoid lesions that had posed diagnostic difficulties. We examined hotspots of mutation in the BRAF, NRAS and HRAS genes by polymerase chain reaction-based direct sequencing. We also analysed DNA copy number aberrations and the methylation of CpG sequences in several cancer-related genes by utilizing a novel methylation-specific multiplex ligation-dependent probe amplification method. RESULTS: Twenty three of 24 conventional melanomas showed at least one of the genetic and epigenetic alterations examined, although one acral melanoma did not show any alteration. By sharp contrast, 12 Spitz naevi with an unambiguous histopathology showed no or few chromosomal aberrations, no oncogene mutations and no methylation of CpG sequences. Of the 16 ambiguous spitzoid lesions, most of which were designated atypical Spitz tumour by one of the authors, all but one showed no mutations, no methylations and few copy number aberrations. However, three tumours showed copy number loss of the cyclin-dependent kinase inhibitor 2A gene (CDKN2A), an alteration observed frequently in melanomas but not found in conventional Spitz naevi. These results show that, although most atypical Spitz tumours do not differ from conventional Spitz naevi showing virtually no genetic and epigenetic aberrations, some cases may have chromosomal aberrations that include copy number loss of the CDKN2A gene. CONCLUSIONS: Genetic and epigenetic analyses may be useful as an additional diagnostic tool to distinguish between melanoma and Spitz naevus, and may help to define subgroups in atypical Spitz tumours.     

The limitations of dermoscopy: false‐positive and false‐negative tumours

Dermoscopy has been documented to increase the diagnostic accuracy of clinicians evaluating skin tumours, improving their ability to detect skin cancer and better recognize benign moles. However, dermoscopically ‘false‐positive’ and ‘false‐negative’ tumours do exist. False‐positive diagnosis usually leads to unnecessary excisions. False‐negative diagnosis is much more dangerous, as it might result in overlooking a cancer, with severe undesirable consequences for the patient and the physician. Therefore, management strategies should mainly focus on addressing the risk of dermoscopically false‐negative tumours. The most frequent benign tumours that might acquire dermatoscopic characteristics suggestive of malignancy are seborrhoeic keratosis (SK), including solar lentigo, melanoacanthoma, irritated, clonal and regressive SK, angioma (mainly thrombosed angioma and angiokeratoma), dermatofibroma, benign adnexal tumours and naevi (Clark, Spitz, recurrent, combined, sclerosing). The most useful clues to recognize these tumours are the following: solar lentigo – broad network; melanoacanthoma – sharp border; irritated SK – regularly distributed white perivascular halos; clonal SK – classic SK criteria; regressive SK – remnants of SK; targetoid haemosiderotic haemangioma – dark centre and reddish periphery; thrombosed angioma – sharp demarcation; angiokeratoma – dark lacunae; atypical dermatofibromas – palpation; follicular tumours – white colour; sebaceous tumours – yellow colour; Clark naevi – clinical context; Spitz/Reed naevi – age; combined naevi – blue central area; recurrent naevi – pigmentation within the scar; sclerosing naevi – age and location on the upper back; blue naevi – history. Malignant tumours that might mimic benign ones and escape detection are melanoma (in situ, nevoid, spitzoid, verrucous, regressive, amelanotic), squamous cell carcinoma (mainly well‐differentiated variants) and rarely basal cell carcinoma (non‐pigmented variants). The most useful clues to recognize the peculiar melanoma subtypes are as follows: melanoma in situ – irregular hyperpigmented areas; nevoid melanoma – history of growth; spitzoid melanoma – age; verrucous melanoma – blue‐black sign; regressive melanoma – peppering or scar‐like depigmentation; amelanotic melanoma – pink colour, linear irregular vessels, dotted vessels. In this article, we summarized the most frequent dermoscopic variations of common skin tumours that are often misinterpreted, aiming to assist clinicians to reduce the number of false diagnoses.     

Understanding spitzoid tumours: new insights from molecular pathology

Spitzoid tumours are a morphologically diverse group of lesions that share histological similarity to the Spitz naevus, a benign melanocytic skin tumour. Distinguishing classic Spitz naevi from cutaneous malignant melanoma is usually achievable on standard histology sections, but occasionally equivocal lesions are encountered that show features intermediate between these two entities and consequently generate considerable clinical and histopathological concern. The nomenclature and diagnostic criteria for spitzoid lesions are not standardized and this article begins by considering the adverse effect this has on our understanding of spitzoid tumour biology. Investigations of some of the hallmark features of cancer and neoplasia in spitzoid tumours are described, and the contribution of these studies to our understanding of spitzoid tumour biology is considered, along with their potential diagnostic utility. These studies compare spitzoid tumours with better-characterized melanocytic lesions, and from such comparisons assumptions concerning the biological nature of different spitzoid tumours can be made. In contrast, investigations of the mitogen-activated protein kinase (MAPK) pathway and DNA gains and losses have suggested that Spitz naevi may be genetically distinct from other melanocytic tumours. The studies that led to this conclusion are reviewed, as well as subsequent work examining whether the same applies to all spitzoid tumours. Possible explanations for the considerable inconsistencies within some of these data are explored. Finally, potential pathways of tumour progression within spitzoid lesions are considered, with an emphasis placed upon insights gained from investigations of MAPK genes and DNA gains and losses.     

Large speckled lentiginous naevus superimposed with Spitz naevi: sequential digital dermoscopy may lead to unnecessary excisions triggered by dynamic changes

We report a 14-year-old girl with a large speckled lentiginous naevus (SLN) on her left arm and shoulder. As the occurrence of melanoma within SLN has been described previously, long-term follow-up of atypical lesions by digital dermoscopy was started at the age of 4 years. To date, nine Spitz naevi and four dysplastic compound naevi have been excised due to dynamic changes over time. No melanoma has so far been detected. We critically discuss the possibility of an 'overtreatment' because of a high rate of physiological changes within SLN of children. In conclusion, we would like to encourage a close follow-up of large SLN whenever complete excision is not an option. In order to avoid unnecessary excisions triggered by subtle dynamic changes, a standard approach with overview images, conventional dermoscopy and early excision of lesions that are rated as suspicious for melanoma by established algorithms may be recommended.     

Atypical Spitz tumour: a 'chameleon' lesion

It is a common experience that many Spitz naevi deviate from the idealized or stereotypical representation found in the literature, often causing considerable difficulties in distinguishing them from melanoma. The diagnostic term 'atypical Spitz naevus' is used to describe lesions that deviate from the typical appearance of Spitz naevi and which have an uncertain biological significance and prognosis. The term 'Spitz tumour' has been proposed for these lesions, as the term 'naevus' indicates a lesion that is completely benign and presents no risk to the patient. We present a case of atypical Spitz tumour with peculiar atypical clinical and dermatoscopic features. The difficulty in managing this Spitz tumour was aggravated by the clinical diagnosis. In fact, the lesion appeared as a benign and nonmelanocytic lesion, a pigmented dermatofibroma. Our case underlines the difficulties present in the controversial chapter of spitzoid melanocytic lesions. The atypical Spitz tumour is a 'chameleon' lesion that can mimic not only melanocytic, but also nonmelanocytic lesions.     

Improvement of malignant/benign ratio in excised melanocytic lesions in the 'dermoscopy era': a retrospective study 1997-2001

BACKGROUND: Because of the many limitations of studies based on the diagnostic setting of excised lesions, the impact of dermoscopy (epiluminescence microscopy, dermatoscopy) in melanoma screening during practice remains to be established. OBJECTIVES: We assumed that effects of the use of dermoscopy on some indicators of diagnostic performance in melanoma screening should be traceable retrospectively; therefore, we analysed the impact of routine dermoscopy use on the malignant/benign ratio in excised melanocytic lesions. METHODS: Preoperative and histological diagnosis of 3053 melanocytic lesions [319 melanomas (10.4%)] consecutively diagnosed and excised at the Department of Dermatology, University of Florence in the period 1997-2001 inclusive were retrieved. Six dermatologists who selected the lesions to excise and who performed preoperative diagnosis were divided into two groups according to their use of dermoscopy in routine activity (n = 2 dermoscopy users and n = 4 nonusers). The study period was divided into a predermoscopy period (1997), a shift phase (1998) and a dermoscopy period (1999-2001). RESULTS: During the study period, the malignant/benign ratio improved in dermoscopy users only (from 1 : 18 to 1 : 4.3, P = 0.037). No significant difference was found for nonusers (from 1 : 11.8 to 1 : 14.4). Dermoscopy users were more likely to have a melanoma diagnosed within a series of excised lesions than nonusers, even taking into account potential confounders such as sex, age and study period by means of multivariate analysis (odds ratio 1.55, 95% confidence interval 1.17-2.01). The percentage of 'problem' naevi (naevi with architectural disorder with or without cytological atypia and Spitz or Reed naevi) over the total number of excised lesions was higher in dermoscopy users than in nonusers (year 2001, 51.6% vs. 40.9%, P = 0.014). Similar findings were obtained after exclusion from the data set of lesions excised for cosmetic reasons. CONCLUSIONS: The adoption of dermoscopy in routine melanoma screening is followed by an improvement of the malignant/benign ratio in excised lesions, suggesting a more appropriate selection of pigmented lesions referred to surgery. Because of the possible limitations of a retrospective study design, future confirmation of this finding by means of a prospective, randomized study is advisable. The introduction of dermoscopy in routine practice may have major implications in large-scale melanoma screening with cost savings and a reduction of the dermosurgery workload.     

Surveillance of patients at high risk for cutaneous malignant melanoma using digital dermoscopy

BACKGROUND: Dermoscopy has improved the sensitivity and specificity of clinical diagnosis of melanoma from 60% to over 90%. However, in order not to miss melanoma a certain percentage of suspicious but benign lesions has to be excised. OBJECTIVES: To evaluate the dermoscopic changes and the rates of excision in benign melanocytic naevi and cutaneous malignant melanoma in long-term follow-up of high-risk patients using digital dermoscopy. METHODS: Digital dermoscopic images of 2015 atypical melanocytic naevi in 196 high-risk patients were analysed retrospectively. Among others, the following data were collected for each naevus: changes in surface area, overall architecture, dermoscopic patterns and distribution of pigmentation. All tumours suspicious for melanoma or showing asymmetrical changes were excised. RESULTS: During a median follow-up time of 25 months 128 (6.4%) of all naevi showed changes in size or architecture. Eighty-six per cent of all changes in patients who attended more than one visit were observed at the first follow-up visit. Thirty-three lesions showing changes were excised and two melanomas in situ and 31 melanocytic naevi were diagnosed. CONCLUSIONS: Follow-up examinations using digital dermoscopy revealed unchanged morphology in the large majority of melanocytic naevi. Excisions were only performed in cases of asymmetrical growth, asymmetrical changes of pigmentation, or development of dermoscopic features indicative of melanoma. The ratio of 33 lesions excised in order to identify two melanomas in situ seems reasonable and may be further reduced in future.     

Dermoscopy for the Pediatric Dermatologist Part III: Dermoscopy of Melanocytic Lesions

Melanocytic nevi encompass a variety of lesions, including blue, Spitz, congenital, and acquired nevi. These nevi can occasionally manifest clinical morphologies resembling melanoma, and the presence of such nevi in children can elicit anxiety in patients, parents, and clinicians. Dermoscopy has been shown to increase the diagnostic accuracy for melanoma and to help differentiate melanoma from nevi, ultimately aiding in the decision‐making process as to whether to perform a biopsy. Dermoscopy is the perfect instrument to use during the evaluation of pigmented skin lesions in children because it is painless and provides important information for the clinician that can assist in formulating appropriate management decisions. This review highlights the most common benign dermoscopic patterns encountered in nevi and discuss the 10 most common dermoscopic structures seen in melanomas. Lesions manifesting a benign dermoscopic pattern and lacking any melanoma‐specific structures do not need to be excised and can safely be monitored. In contrast, melanomas will invariably deviate from the benign nevus patterns and will usually manifest at least 1 of the 10 melanoma‐specific structures: atypical network, negative network, streaks, crystalline structures, atypical dots and globules, irregular blotch, blue‐white veil, regression structures, peripheral brown structureless areas, and atypical vessels. It is important to be cognizant of the fact that melanomas in childhood usually do not manifest the clinical ABCD features. Instead, they are often symmetric, amelanotic, nodular lesions. Although the clinical appearance may not be alarming, with dermoscopy they will invariably manifest at least one melanoma‐specific structure, the most common being atypical vascular structures and crystalline structures.     

Spitz Nevi and Other Spitzoid Neoplasms in Children: Overview of Incidence Data and Diagnostic Criteria

Spitz nevi are benign melanocytic neoplasms characterized by epithelioid or spindle melanocytes or both. In some rare cases their presentation overlaps with the clinical and histopathologic features of malignant melanoma, so a differential diagnosis can be difficult to make. Intermediate forms between Spitz nevi and malignant melanoma, with unpredictable behavior, have been called atypical Spitz tumors. A literature search was performed to review the clinical, dermoscopic, genetic, and histopathologic aspects of spitzoid tumors. Spitz nevi mainly occur in children, with no predilection for sex, and in young women. Common sites are the head and lower arms, where Spitz nevi present as pink nodules or hyperpigmented plaques. Spitzoid lesions may have diverse dermoscopic patterns: vascular, starburst, globular, atypical, reticular, negative homogeneous, or targetoid. The management of spitzoid lesions can be invasive or conservative; surgical excision is usually reserved for those with doubtful features, whereas clinical and dermoscopic follow‐up is preferred for typical pediatric Spitz nevi. The role of sentinel lymph node biopsy in atypical Spitz tumors is debated. Immunohistochemistry and new molecular techniques such as comparative genomic hybridization, polymerase chain reaction, and fluorescence in situ hybridization offer new diagnostic perspectives, investigating genetic alterations that are specific for malignant melanoma or for Spitz nevi.     

Oncogenic BRAF and the tumor suppressor IGFBP7 in the genesis of atypical spitzoid nevomelanocytic proliferations

Rare reports indicate that the frequency of BRAFV600E mutations is high in atypical Spitz nevi. The purpose of this study was to ascertain the utility of the RAF/RAS mutational status as a diagnostic adjunct in lesions with histologic features that deviate from a typical Spitz nevus and, to examine expression of Insulin growth factor binding protein 7 (IGFBP7), a tumor suppressor acting through autocrine/paracrine pathways to inhibit BRAF‐MEK‐ERK signaling, in the same. Genomic DNA for genotyping was isolated from 6 regular Spitz nevi and 14 atypical spitzoid nevomelanocytic proliferations (including 1 melanoma with spitzoid histomorphology). NRAS1, NRAS2 and KRAS were analyzed, in addition to BRAFV600E. A mutation in BRAFV600E was noted in only one case–that of a regular Spitz nevus. IGFBP7 expression appeared to be maintained in this case, but was absent in 7/17 cases, which included 5 atypical spitzoid nevomelanocytic proliferations. Lack of expression of IGFBP7 in atypical spitzoid nevomelanocytic proliferations with histologically concerning features but BRAF‐WT indicates that the evolutionary path in atypical spitzoid nevomelanocytic proliferations is genetically distinct from that of IGFBP7‐negative BRAF‐positive melanoma. From an oncogenic BRAF perspective, our findings suggest that the majority of ‘atypical’ spitzoid nevomelanocytic proliferations are probably no different from conventional Spitz nevi. Emley A, Yang S, Wajapeyee N, Green MR, Mahalingam M. Oncogenic BRAF and the tumor suppressor IGFBP7 in the genesis of atypical spitzoid nevomelanocytic proliferations.     

Evaluation of tumour-infiltrating CD4+CD25+FOXP3+ regulatory T cells in human cutaneous benign and atypical naevi, melanomas and melanoma metastases

BACKGROUND: CD4+CD25+FOXP3+ regulatory T cells (Tregs) are thought to induce immunotolerance in melanoma. They have not yet been investigated in the entire spectrum of melanocytic cutaneous lesions within a tumour site. OBJECTIVES: To evaluate CD4+CD25+FOXP3+ Tregs among tumour-infiltrating lymphocytes in cutaneous melanocytic lesions. METHODS: We analysed 128 lesions (10 benign junctional common naevi, 10 benign compound common naevi, 10 compound Spitz naevi, 10 junctional atypical naevi, 20 compound atypical naevi, 20 radial growth phase melanomas, 30 vertical growth phase melanomas and 18 melanoma metastases). Tregs were identified by CD25-FOXP3 double immunostains. RESULTS: This study indicates that CD4+/CD25+FOXP3+ Tregs are present in all groups of lesions. Junctional atypical naevi, compound atypical naevi and radial growth phase melanomas showed the highest percentages of CD4+CD25+FOXP3+ Tregs (junctional atypical naevi vs. junctional common naevi, compound common naevi, compound Spitz naevi, melanoma metastases: P < 0.0001; junctional atypical naevi vs. vertical growth phase melanomas: P = 0.001; compound atypical naevi vs. junctional common naevi, compound common naevi: P < 0.0001; compound atypical naevi vs. compound Spitz naevi, melanoma metastases: P = 0.002; compound atypical naevi vs. vertical growth phase melanomas: P = 0.02; radial growth phase melanomas vs. junctional common naevi, compound common naevi, compound Spitz naevi, melanoma metastases: P < 0.0001; radial growth phase melanomas vs. vertical growth phase melanomas: P = 0.008). CONCLUSIONS: The strong prevalence of CD25+FOXP3+ Tregs both in junctional and compound atypical naevi and radial growth phase melanomas, suggests that they induce immunotolerance early during melanoma genesis, favouring melanoma growth. Their evaluation within a tumour site could be useful for prognostic and therapeutic purposes.     

Morphologic changes of a pigmented Spitz nevus assessed by dermoscopy

Pigmented Spitz nevus may simulate cutaneous melanoma clinically and histopathologically. In an effort to characterize Spitz nevi using dermoscopy, we documented the dermoscopic features of a single pigmented Spitz nevus over a 6-month period. A 3-year-old boy had a brownish black papule, 3 mm in diameter, on the dorsum of the first finger of his left hand, clinically diagnosed as a Reed nevus. Two follow-up examinations were performed after 3 and 6 months, when the lesion finally was excised for histopathologic examination. Dermoscopically, a globular pattern was recognized during the initial examination, whereas a starburst pattern was identified 3 months later. After 6 months, a variation of the starburst pattern was still detectable. Based on our observation, the globular and the starburst patterns might be considered different morphologic expressions corresponding to the evolutionary phases of pigmented Spitz nevi.     

Seven-point checklist of dermoscopy revisited

Background Most dermoscopic algorithms to diagnose melanoma were established more than 10 years ago and have been tested primarily on clear‐cut melanomas and excised melanocytic naevi. Objectives To assess the diagnostic performance of pattern analysis and seven‐point checklist on lesions that reflect the current clinical setting, compared with a revised seven‐point checklist with a lower threshold for excision. Methods Eight experienced dermatologists viewed dermoscopic images of 100 excised melanomas, 100 excised naevi and 100 monitored naevi. Each lesion was evaluated by pattern analysis and scored as naevus, melanoma or lesion to be excised. Images were then evaluated using the seven‐point criteria, with both standard and revised thresholds for excision. Results Pooled data using the pattern analysis algorithm showed that 82% of melanomas and 87·5% of monitored naevi were correctly scored as lesion to be excised and benign naevus, respectively. Using the standard and revised thresholds for the seven‐point checklist, excision was recommended for 77·9% and 87·8% of the lesions in the melanoma set, respectively. The standard threshold produced ‘no excision’ recommendations for 85·6% of the monitored naevi, compared with 74·5% using the revised threshold. Pattern analysis, standard seven‐point and revised seven‐point algorithms resulted in recommendations of ‘excision’ for 63·6%, 60·3% and 72·0% of the excised naevi, respectively. Conclusions The diagnostic approach to naevi and melanoma should be adapted to the current clinical setting, in which patients may present with early‐stage melanomas and multiple atypical naevi. To increase sensitivity, a revised seven‐point checklist with a lower threshold for excision should be used.     

Nevo de Spitz y otros tumores spitzoides en la infancia. Parte 1: aspectos clínicos,histológicos e inmunohistoquímicos

A Spitz nevus is a melanocytic neoplasm of epithelioid and/or spindle cells that usually appears in childhood. These lesions are by nature benign, but their features can sometimes make them difficult to distinguish from melanomas. Spitzoid melanocytic lesions have been grouped into 3 types in recent decades: Spitz nevi, atypical Spitz tumors, and spitzoid melanomas. Atypical Spitz tumors are spitzoid melanocytic proliferations that have atypical histopathologic features that are insufficient to support a diagnosis of melanoma. The malignant potential of these lesions is at present uncertain. This review examines the clinical, dermoscopic, and histopathologic features of this group of lesions.     

Spitzoid melanoma and micrometastases in two lymph node regions: a critical situation

Atypical Spitz tumors can hardly be differentiated from spitzoid melanoma. CGH might help in the differential diagnosis. An 8 year old child with an atypical Spitz tumor (with a CGH pattern compatible with melanoma) of 8.0?mm Breslow thickness and micrometastases in two lymph node regions was seen at our department. The management and prognosis of atypical Spitz tumors is controversial, and aggressive procedural steps similar to melanoma are usually not recommended. Even performing sentinel lymph node biopsy has been questioned. After extensive interdisciplinary consultations, we did not recommend resection of both lymph node regions and chose instead to follow-up with regular whole-body MRI and adjuvant treatment with pegylated interferon. Treatment decisions for atypical Spitz tumors are a major medical and ethical challenge due to the limited available data.     

Clinical features and outcomes of spitzoid proliferations in children and adolescents

Spitz naevi are a type of mole (brown skin lump). They are smooth, rounded, pink, red or brown. They contain pigment cells known as spitzoid proliferations. Some spitz naevi look quite worrying, growing rapidly and dark brown in colour, and yet turn out to be benign (harmless) when looked at under the microscope, while others contain atypical (abnormal) or even malignant cells. Even viewing them under a powerful magnifying glass (dermatoscope) does not show whether they are malignant (cancerous); genetic tests provide clues but are not easily available. Consequently it is hard to advise patients, especially children because most of the published data is from adults. So these American doctors reviewed 622 spitzoid proliferations removed at Boston Children's Hospital between 1994 and 2012. Most (82.3%) were benign, 17.2% contained cells that looked worrying (atypical) and 3 (0.5%) turned out to be malignant melanomas. On further investigation they found that patients with malignant lesions were, on average, older (17.2 years) than those with atypical or benign lesions (7.2 and 7.4 years respectively), but tumour type was not linked with skin colour or gender. The 3 melanomas occurred in white people, one on the arm, and the other two on or around the buttocks. Two of the 3 had other tumours but all 3 were alive with no recurrences of skin tumour when last reviewed 4-17 years after diagnosis. Five typical spitz naevi came back as atypical naevi after being partially removed. The authors conclude that it may not be necessary to remove benign-looking spitz naevi in children.     

Epidermolysis bullosa naevi reveal a distinctive dermoscopic pattern

BACKGROUND: Large, asymmetrical and irregularly pigmented naevi in patients with epidermolysis bullosa (EB) have been reported often to mimic cutaneous melanoma clinically. OBJECTIVES: As the biological course of these peculiar moles is benign, we assessed EB naevi with a dermatoscope to determine whether they could be reliably differentiated from cutaneous melanoma. METHODS: We evaluated digital dermoscopic images of 23 EB naevi from 11 patients with EB and analysed these pigmented lesions according to pattern analysis, ABCD rule of dermoscopy and the seven-point checklist. RESULTS: Melanoma-associated dermoscopic criteria such as multicomponent pattern (20 of 23), atypical pigment network (17 of 23), irregular dots/globules (16 of 23), irregular pigmentation (22 of 23) and an atypical vascular pattern (seven of 23) were frequently seen in EB naevi. In contrast, other criteria frequently associated with melanoma progression, such as irregular streaks, blue-whitish veil, regression structures (blue-whitish areas) or black dots, were rarely seen. Most lesions gave false-positive results when the scores of the dermoscopic diagnostic algorithms were calculated. CONCLUSIONS: Recurring dermoscopic structures in EB naevi reveal a distinctive dermoscopic pattern of this recently defined entity. Although EB naevi represent an exception to dermoscopic diagnostic algorithms, their dermoscopic evaluation most often allows us to estimate their benign nature. Nevertheless, as an unequivocal discrimination from malignant melanoma in vivo is sometimes not possible, regular clinical follow up of EB naevi with histopathological evaluation of highly suspicious lesions is mandatory.     

Agminate Spitz naevi occurring in an adult after the excision of a solitary Spitz naevus — report of a case and review of the literature

We describe a 21-year-old female who presented with tour agminate Spitz naevi close to the scar from a previously excised solitary Spitz naevus, and review the literature since 1987 on widespread and agminate Spitz naevi. Spitz naevi usually present as solitary firm red or brown popular lesions. Agminate Spitz naevi are unusual and they have been reported mainly in children. It is uncommon for Spitz naevi to recur after surgery and far more unusual for a recurrence to occur in an agminate form. Such lesions may mimic multiple satellite and in-transit metastases which can occur in malignant melanoma, and close follow up of any new lesions occurring in this case is intended.