Spitz nevus: follow-up study of 8 cases of childhood starburst type and proposal for management

Spitz nevus is an uncommon, benign melanocytic neoplasm that shares many clinical and histological features with melanoma. It presents clinical ambiguity that makes the diagnosis and management of the patient difficult. We present our experience in the management of Spitz nevus by rigorous dermoscopic long-term follow-up of 8 Spitz nevi in patients younger than 12 years. Dermoscopic images, acquired every 6 months, show evolution and modifications of these lesions. The aim of this paper is to better understand the long-term modifications of nevi with starburst pattern to avoid surgical excision of these lesions in the pediatric age group.     

Clinical and dermoscopic features of small Reed nevus (<6 mm)

Background The differential diagnosis between Reed nevi and melanoma becomes more difficult if the lesion to analyse presents a small size, with a diameter of 6 mm or smaller. Many studies have reported various dermoscopic features of Reed nevi during their growth phases. In early stages of evolution, the lesions generally show a characteristic globular appearance typically found in childhood, followed by the so‐called starburst pattern. Objective The aim of the study was to identify the main dermoscopic features in small Reed nevi (<6 mm in size). Methods Using a computerized skin‐imaging database for melanoma prevention surgery at the Department of Dermatology of the University of Florence, 15 Reed nevi were selected among 103 small (<6 mm) melanocytic lesions consecutively excised. Images of small Reed nevi, independently blinded to histopathological diagnosis, were administered to a dermatologist expert in dermoscopy, who separately examined the clinical and the dermatoscopic images of small Reed nevi and evaluated their clinical and dermoscopic parameters. Results Analysis of the main dermoscopic patterns showed that 40% had a reticular pattern, 20% had a starburst pattern, 6.5% had a globular pattern, 6.5% had a homogeneous pattern and 27% had an atypical pattern. Conclusion We propose that small, early‐stage Reed nevus are not characterized by an evolution of growth patterns to a phenotype typical of larger lesions. We assume that the patterns are distributed in a linear manner between age groups, may all be present at the outset and thus are independent from the various stages of nevus development.     

Is rituximab therapy a risk factor for development of melanoma?

In the literature, there are reports about dermoscopic and size changes of nevi in patients undergoing biologic therapy and chemotherapeutics. There has not been any established data for melanoma and Rituximab therapy. Sixteen patients, with 94 nevi were included in this study. Dermoscopic images of follow‐up visits, which were performed at baseline, 3, 6, and 12 months after treatment, were evaluated. Suspicious lesions were excised. There was no increase in total nevus count. Although 61.7% of the 94 nevi have shown a stable duration without size changes, 26.5% had enlarged, and 11.7% had become smaller during our 1‐year experience of dermoscopic monitoring. There was not any pattern transformation. Atypical dots and clods appeared in 17% of nevi. All of the excised nevi were comparable with Clark nevi, there was no clue for melanoma development. According to our results, we found that Rituximab therapy influences nevus morphology, but there is no evidence that this was linked to melanoma development.     

Dermoscopic Evolution of Pediatric Nevi

BackgroundThe incidence of pediatric melanoma is very rare. Dermoscopic features help to distinguish pediatric melanoma and common nevi.ObjectiveTo study the evolution of dermoscopic findings in benign nevi in childhood through serial observation and photography.MethodsWe examined 504 melanocytic lesions in 100 patients. From each participant, dermoscopic images of the nevi from 4-year dermoscopic follow-up were obtained, including randomly selected nevi.ResultsThe most common dermoscopic patterns were homogeneous (193 nevi; 38.3%), globular (92 nevi; 18.3%), and reticular (86 nevi; 17.1%). Dermoscopic pattern changes were detected in 27% of patients aged 2~10 years and in 20% of patients aged 11~16 years. The main pattern changes consisted of the transition from homogeneous to globular-homogeneous (16%), from homogeneous to reticular-homogeneous (12%) and from globular to globular-homogeneous (10%). Although 257 of the 504 nevi (51.0%) have stable duration without size changes, 169 of the 504 nevi (33.5%) were enlarged, and 78 of the 504 nevi (15.5%) had become smaller.ConclusionThese results contrast with the prevailing view that dermoscopic patterns in pediatric nevi are usually characterized by globular patterns and that melanocytic nevi generally undergo a characteristic transition from a globular pattern to a reticular pattern. Fifty one percent of patients did not exhibit a size change. While 33% of patients had symmetrical enlargement, 15% of patients had involution. Therefore, enlargement is a common dermoscopic change in pediatric nevi, and is not a specific sign of pediatric melanoma.     

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.     

The spectrum of Spitz nevi: a clinicopathologic study of 83 cases

OBJECTIVE: To achieve a clinicopathologic classification of Spitz nevi by comparing their clinical, dermoscopic, and histopathologic features. DESIGN: Eighty-three cases were independently reviewed by 3 histopathologists and preliminarily classified into classic or desmoplastic Spitz nevus (CDSN, n = 11), pigmented Spitz nevus (PSN, n = 14), Reed nevus (RN, n = 16), or atypical Spitz nevus (ASN, n = 14); the remaining 28 cases were then placed into an intermediate category (pigmented Spitz-Reed nevus, PSRN) because a unanimous diagnosis of either PSN or RN was not reached. SETTING: University dermatology and pathology departments and general hospital pathology departments. PATIENTS: A sample of subjects with excised melanocytic lesions. MAIN OUTCOME MEASURE: Frequency of dermoscopic patterns within the different histopathologic subtypes of Spitz nevi. RESULTS: Overlapping clinical, dermoscopic, and histopathologic findings were observed among PSN, RN, and PSRN, thereby justifying their inclusion into the single PSRN diagnostic category. Asymmetry was the most frequent indicator of histopathologic ASN (79%; n = 11); in only 4 cases did dermoscopic asymmetry show no histopathologic counterpart, and in those cases the discrepancy was probably the result of an artifact of the gross sampling technique carried out with no attention to the dermoscopic features. CONCLUSIONS: Among Spitz nevi, histopathologic distinction between PSN and RN is difficult, not reproducible, and may be clinically useless. A simple clinicopathologic classification of these neoplasms might therefore be structured as CDSN, PSRN, and ASN. Asymmetry should be assessed using both dermoscopic and histopathologic analysis, and reliability in histopathologic diagnosis may be enhanced by the simultaneous evaluation of the corresponding dermoscopic images.     

Spitz nevus and Reed nevus

Spitz and Reed nevi, also called spindle and/or epithelioid cell nevi, are a special group of melanocytic lesions due to their peculiar clinical, dermoscopic and histopathological features. The study of these nevi is of great interest because both their nomenclature and classification are still a matter of discussion. Most importantly, the difficulty to differentiate them from melanoma can lead to inadequate therapies. In this context, dermoscopy, a link between clinical and anatomopathological examinations, appears as a helpful diagnostic tool whose accuracy can reach 93%. "Borderline" lesions are still a great challenge and object of research, including molecular studies. The present study explores the relevant characteristics of these nevi, with emphasis on dermoscopic findings, aiming at understanding their natural history, as well as discussing treatment and patient follow-up.     

Cloudy and starry milia‐like cysts: how well do they distinguish seborrheic keratoses from malignant melanomas?

Background Seborrheic keratoses are the most common skin lesions known to contain small white or yellow structures called milia‐like cysts (MLCs). Varied appearances can sometimes make it difficult to differentiate benign lesions from malignant lesions such as melanoma, the deadliest form of skin cancer found in humans. Objective The purpose of this study was to determine the statistical occurrence of MLCs in benign vs. malignant lesions. Methods A medical student with 10 months experience in examining approximately 1000 dermoscopy images and a dermoscopy‐naïve observer analysed contact non‐polarized dermoscopy images of 221 malignant melanomas and 175 seborrheic keratoses for presence of MLCs. Results The observers found two different types of MLCs present: large ones described as cloudy and smaller ones described as starry. Starry MLCs were found to be prevalent in both seborrheic keratoses and melanomas. Cloudy MLCs, however, were found to have 99.1% specificity for seborrheic keratoses among this group of seborrheic keratoses and melanomas. Conclusion Cloudy MLCs can be a useful tool for differentiating between seborrheic keratoses and melanomas.     

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.     

Melanoma mimicking seborrheic keratosis: an error of perception precluding correct dermoscopic diagnosis

Seborrheic keratosis is a common skin lesion that can usually be recognized either clinically or dermoscopically. However, melanomas mimicking seborrheic keratoses, as well as melanomas arising in association with seborrheic keratoses, have been described. We report the case of a patient with a lesion that initially revealed "classic" dermoscopic features of a seborrheic keratosis. However, during follow-up, changes in color developed within the center of the lesion that led the clinician to the correct diagnosis of melanoma. Upon retrospective evaluation of the baseline image of the lesion; the clinician was now able to "see" that which his brain could not appreciate on initial examination and to realize that the lesion had subtle features suspect for melanoma. This case represents a diagnostic pitfall due to errors in perception. Dermatologists should be cognizant of "errors in perception"; we suggest that a final dermoscopic judgment of a seborrheic keratosis be rendered by combining the gestalt diagnosis of the overall pattern, with deliberate dermoscopic analysis of all quadrants of the lesion.     

Evaluation of DNA ploidy in dysplastic and Spitz nevi by flow cytometry

As many as 40% of all primary cutaneous melanomas can have histologic remnants of nevomelanocytic nevi adjacent to the tumor. There is increasing evidence that dysplastic nevi are at least a clinical marker for melanoma risk. Spitz nevi are not known for such an association, but are noteworthy because of their histologic appearances. Spitz and dysplastic nevi were studied by flow cytometry to search for DNA abnormality. The study material consisted of formalin-fixed, paraffin embedded material of 41 dysplastic nevi and 14 Spitz nevi. Four cases of dysplastic nevi were excluded for technical reasons. Of the 37 interpretable histograms from dysplastic nevi, 28 (76%) were diploid and nine (24%) were aneuploid. All the Spitz nevi were diploid. Thus, dysplastic nevi, but not Spitz nevi, share aneuploidy features in some cases with melanoma. Previous authors have demonstrated aneuploidy in melanoma with aggressive behavior and in those in deep vertical growth phase. Aneuploidy may be a feature of early as well as late stages of tumor progression regarding the nevomelanocyte system.     

Dermoscopy of cutaneous melanoma metastases: A color‐based pattern classification

Dermoscopic studies about cutaneous metastases of malignant melanoma (CMMM) are few. Our objective was to analyze the dermoscopic features of CMMM and propose a new dermoscopic pattern classification based on color pigmentation and some specific dermoscopic features. A retrospective evaluation of 150 dermoscopic images of CMMM taken from 40 patients was performed. One hundred CMMM images were individually evaluated by six dermatologists in order to classify them according to four dermoscopic patterns: (i) blue pattern; (ii) pink pattern; (iii) brown pattern; and (iv) mixed pattern. One hundred and fifty dermoscopic images including 50 CMMM and 100 benign lesions were evaluated by five dermatologists to calculate the accuracy of these patterns in the recognition of CMMM. An intra‐ and interobserver reproducibility agreement study between all different dermoscopic pattern classifications was performed. Seventy‐five percent of our cases of CMMM showed a monochromatic pattern. Light brown pigmented halo, peripheral gray spots and polymorphic atypical vessels were the most significant focal dermoscopic structures. The reproducibility of the color‐based dermoscopic pattern classification was superior to previous dermoscopic pattern classification. In summary, a dermoscopic pattern classification based on color pigmentation and some specific dermoscopic features may be useful in recognizing early cutaneous melanoma metastasis. Multicentric studies are recommended in order to lower the impact of interobserver variability.     

Three years dermoscopic follow‐up of atypical nevi

Atypical nevi are dynamic lesions and may progressively transform into more or less atypical lesions. We aimed to investigate the dermoscopic features of atypical nevi and dynamic changes in these lesions over a period of 3‐years. Patients with 3‐year dermoscopic follow‐up records were enrolled in the study. We compared the dermatoscopic features of the nevus recorded in the first dermoscopic examination and at the end of the third year. Changes in size (mm), pattern, and color were investigated. The most common dermoscopic patterns were reticular (18 patients; 34%), reticular‐homogeneous (17 patients; 32.1%), and reticular‐globular (7 patients; 13.2%). The most common pigmentation patterns were central hyperpigmentation (28 patients; 52.8%), regular pigmentation (nine patients; 17.0%), and multifocal hypo/hyperpigmentation (eight patients; 15.1%). Twenty‐one (39.6%) patients showed changes in pattern. The transformation from reticular‐homogeneous pattern to the homogeneous pattern was the most frequent change in pattern (7 of 21 patients; 33.3%). The transformation from reticular pattern to reticular‐homogeneous pattern was the second most common change in pattern (5 of 21 patients; 23.8%). Fourteen (26.4%) patients experienced symmetrical enlargement. Symmetrical enlargement was statistically more frequent in patients who showed dermoscopic changes in pattern than in those who did not show any changes in the pattern (p: .038). In this study, we did not observe any new dermoscopic clues for the diagnosis of melanoma during the follow‐up. The nevi tended to turn into a homogeneous (structureless) pattern. We observed that the most common dermoscopic change in pattern was the transformation from reticular‐homogeneous pattern to homogeneous pattern, and the lesions had symmetrical enlargement during this transformation. In conclusion, despite the known association between atypical nevi and the risk of developing melanoma, most atypical nevi do not transform into melanoma. Therefore, our study suggests that the excision of atypical nevi is not necessary and dermatoscopic follow‐up can reduce the number of unnecessary excisions.     

A systematic heuristic approach for feature selection for melanoma discrimination using clinical images

BACKGROUND: Numerous features are derived from the asymmetry, border irregularity, color variegation, and diameter of the skin lesion in dermatology for diagnosing malignant melanoma. Feature selection for the development of automated skin lesion discrimination systems is an important consideration. METHODS: In this research, a systematic heuristic approach is investigated for feature selection and lesion classification. The approach integrates statistical-, correlation-, histogram-, and expert system-based components. Using statistical and correlation measures, interrelationships among features are determined. Expert system analysis is performed to identify redundant features. The feature selection process is applied to 19 shape and color features for a clinical image data set containing 355 malignant melanomas, 125 basal cell carcinomas, 177 dysplastic nevi, 199 nevocellular nevi, 139 seborrheic keratoses, and 45 vascular lesions. RESULTS: Experimental results show reduced lesion classification error rates based on condensing the shape and color feature set from 19 features to 13 features using the feature selection process. Specifically, average test lesion classification error rates for discriminating malignant melanoma from non-melanoma lesions were reduced from 26.6% for 19 features to 23.2% for 13 features over five randomly generated training and test sets. CONCLUSIONS: The experimental results show that the systematic heuristic approach for feature reduction can be successfully applied to achieve improved lesion discrimination. The feature reduction technique facilitates the elimination of redundant information that may inhibit lesion classification performance. The clinical application of this result is that automated skin lesion classification algorithm development can be fostered with systematic feature selection techniques.     

Colour histogram analysis for melanoma discrimination in clinical images

Background: Malignant melanoma, the most deadly form of skin cancer, has a good prognosis if treated in the curable early stages. Colour provides critical discriminating information for the diagnosis of malignant melanoma.
Methods: This research introduces a three-dimensional relative colour histogram analysis technique to identify colours characteristic of melanomas and then applies these 'melanoma colours' to differentiate benign skin lesions from melanomas. The relative colour of a skin lesion is determined based on subtracting a representative colour of the surrounding skin from each lesion pixel. A colour mapping for 'melanoma colours' is determined using a training set of images. A percent melanoma colour feature, defined as the percentage of the lesion pixels that are melanoma colours, is used for discriminating melanomas from benign lesions. The technique is evaluated using a clinical image data set of 129 malignant melanomas and 129 benign lesions consisting of 40 seborrheic keratoses and 89 nevocellular nevi.
Results: Using the percent melanoma colour feature for discrimination, experimental results yield correct melanoma and benign lesion discrimination rates of 84.3 and 83.0%, respectively.
Conclusions: The results presented in this work suggest that lesion colour in clinical images is strongly related to the presence of melanoma in that lesion. However, colour information should be combined with other information in order to further reduce the false negative and false positive rates.     

Vascularización en dermatoscopia

Under the right conditions, dermoscopy allows us to observe the vascular features of many different types of skin lesions. The visualization and identification of vessels with a characteristic morphology can be the key to diagnosis, especially in hypopigmented lesions in which the typical pigmented structures are not visible.Some of the more characteristic associations are the presence of crown vessels in sebaceous hyperplasia, arborizing telangiectasias in basal cell carcinoma, comma-shaped vessels in intradermal and compound nevi, dotted vessels in Spitz nevi and melanoma, and hairpin vessels in seborrheic keratoses.The recognition of distinctive vascular features can be of great help in the diagnosis of many types of skin lesions, and very often such patterns are the only key to the diagnosis of melanoma.     

A relative color approach to color discrimination for malignant melanoma detection in dermoscopy images

BACKGROUND: Skin lesion color is an important feature for diagnosing malignant melanoma. In previous research, skin lesion color was investigated for discriminating malignant melanoma lesions from benign lesions in clinical images. Colors characteristics of melanoma were determined using color histogram analysis over a training set of images. Percent melanoma color and color clustering ratio features were used to quantify the presence of melanoma-colored pixels within skin lesions for skin lesion discrimination. METHODS: In this research, the relative color histogram analysis technique is used to evaluate skin lesion discrimination based on color feature calculations in different regions of the skin lesion in dermoscopy images. The histogram analysis technique is examined for varying training set sizes from the set of 113 malignant melanomas and 113 benign dysplastic nevi images. RESULTS: Experimental results show improved discrimination capability for feature calculations focused in the interior lesion region. Recognition rates for malignant melanoma and dysplastic nevi as high as 87.7% and 74.9%, respectively, are observed for the color clustering ratio computed using the outer 75% uniformly distributed area with a 10% offset within the boundary. CONCLUSIONS: Experimental results appear to indicate that the melanoma color feature information is located in the interior of the lesion, excluding the 10% central-most region. The techniques presented here including the use of relative color and the determination of benign and malignant regions of the relative color histogram may be applicable to any set of images of benign and malignant lesions.     

Reed nevus (pigmented spindle-cell nevus): a report of three cases with distinct dermoscopic patterns

Reed nevus or pigmented spindle-cell nevus may mimic cutaneous melanoma; however, its dermoscopic and histopathological characteristics are different. This case report describes three patients with distinct clinical, dermoscopic and histopathological presentations, which were correlated to enable a differential diagnosis to be made between melanoma and Spitz nevus.     

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.