Melanocytic nevi with features of Spitz nevi and Clark's/dysplastic nevi ("Spark's" nevi)

Background: Nevi with cytologic characteristics of Spitz nevus and architectural features of Clark's/dysplastic nevus are not well recognized in the literature.
Methods: Twenty-seven nevi with characteristics of Spitz nevus and Clark's/dysplastic nevus are reviewed.
Results: The patients' mean age was 33 years, and 17/27(63%) patients were female. Lesions were most frequent on the trunk and lower extremities. Histopathologically, these nevi were composed of large, monomorphous spindled and/or epithelioid melanocytes. Spindle cells were often oriented parallel to the epidermis, with fused rete and lamellar fibroplasias. Lateral extension of the junctional component was a feature of compound lesions. An average of 10 years of clinical follow up in 12 patients revealed no recurrence or metastasis.
Conclusions: Recognition of this type of nevus is important to avoid confusion with malignant melanoma.     

Total-body photographs of dysplastic nevi

A method of taking total-body photographs to document dysplastic nevi is described. A set of 24 views is taken. These 35-mm color slide transparencies are projected onto a rearview screen at the time of subsequent follow-up examinations. A comparison between the baseline photographs and the current clinical findings allows the physician to detect thin malignant melanomas in a curable stage.     

Clinical features of dysplastic nevi

The clinical features of 100 dysplastic nevi were tabulated. Although certain characteristics were present in most or all of these melanocytic nevi, there was a marked heterogeneity of other clinical features. The preponderant type of large (greater than or equal to 8 mm) melanocytic nevus in patients with classic dysplastic nevi is a papule or plaque with the following characteristics: multicoloration (various shades of tans, browns, reds, or black); slightly raised height for its broad diameter; mamillated surface; and lack of hypertrichosis. An atlas illustrates some of the clinical varieties of melanocytic nevi in this syndrome.     

Image analysis cytometry of dysplastic nevi

Computerized image analysis was used to assess nuclear atypia in 24 dysplastic nevi (DN), 19 CN (CN), and five thin melanomas. DN were selected for the study using architectural criteria alone. Feulgen-stained, 6-um sections were analyzed with a microTICAS cytometer. At least 100 nuclei were measured in each case. The standard deviation of nuclear area, mean nuclear roundness, standard deviation of nuclear roundness, mean ploidy, and standard deviation of ploidy were found to be significantly greater for DN than for CN. DNA histograms from DN showed an increased fraction above 2N, suggesting that DN are more proliferative than CN. No DN were aneuploid. All melanomas were aneuploid, and differed significantly from DN in mean nuclear area, standard deviation of nuclear area, mean ploidy, and standard deviation of ploidy. There were no significant differences between the junctional and intradermal populations of compound DN in any of the measured parameters, except that the intradermal nuclei were significantly rounder than the junctional nuclei. There were no significant differences between DN from patients with only a single DN and DN from patients with at least two dysplastic nevi.     

Quantification of histologic features of dysplastic nevi

We quantified the histologic features of 100 consecutive dysplastic nevi. Although there is heterogeneity in the microscopic attributes of dysplastic nevi, certain features that are seen repeatedly should enable the histologic identification of these melanocytic neoplasms. These features include a central dermal nevocytic component with a peripheral extension of a junctional component, elongated epidermal rete ridges, bridging of nests of melanocytes at the dermo-epidermal junction, nests of melanocytes at the sides of rete ridges as well as at their bases, and concentric eosinophilic fibrosis. Cytologic features of melanocytes were not as valuable as architectural features of individual nevi in classifying these lesions. We also provide an atlas of selected histologic features that depicts some aspects of this heterogeneity.     

Eruptive post-chemotherapy in situ melanomas and dysplastic nevi

A 22-year-old white man without a personal or family history of atypical nevi had received chemotherapy for pre-B-cell acute lymphocytic leukemia at age 17 that included L-asparaginase, prednisone, methotrexate, mercaptopurine, daunorubicin, and cytoxan. Two to three months after completing maintenance chemotherapy, the patient reports he developed many moles, which remained stable for approximately 2 years. Upon examination, two dark, atypical appearing plaques with irregular borders and numerous pink papules of varying shapes and sizes were noted on his chest, back, and abdomen. Histology of specimens of both types of lesions revealed three moderately atypical compound dysplastic melanocytic nevi and three in situ melanomas. The lesions with only features of dysplastic nevi exhibited dermal fibrosis, cytologic atypia, junctional shoulders, lentiginous spread, and focal pigmentation. The lesions with in situ melanomas in addition demonstrated pagetoid spread, extension down adnexal structures, and more severe cytologic atypia. Malignant melanoma has been associated with chronic immunosuppression, and benign nevi have been reported to erupt after chemotherapy. We report an occurrence of multiple eruptive dysplastic nevi and in situ melanomas appearing shortly after completion of chemotherapy.     

Benign dermoscopic network patterns in dysplastic melanocytic nevi

Background/aims: Epiluminescence microscopy (ELM) is a non-invasive clinical technique, which by employing the optical phenomenon of oil immersion makes surface structures of the skin accessible for in vivo examination and provides additional criteria for the diagnosis of pigment skin lesions (PSLs). Many ELM criteria have been described. One of the most important ELM criteria is the pigment network (PN).
Objective: The aim of this study is to identify benign ELM (dermoscopic) network patterns of dysplastic melanocytic nevi (DMN).
Methods: This study included 907 dysplastic melanocytic nevi in 178 patients. Prior to biopsy, each lesion was photographed with oil immersion, and the images were viewed on a high-resolution compact slide projector. For each PSL, the ELM Network Features and ABCD-score were evaluated.
Results and discussion: The benign dermoscopic network features in DMN are the presents of a regular PN with delicate lines and margins, which predominantly thins out at the border of the lesion. For DMN, with these features, the mean ABCD score is smaller than ABCD-score for DMNs with irregular, prominent PN and network patches, ending abruptly at the periphery. In DMN with a network predominantly thinning out at the border of the lesion several uniform network patterns were found—diffuse network pattern, patchy network pattern, structureless center pattern, globular center pattern, and pigmented-blotch center pattern.
Conclusions: Benign features of pigment network are regularity, delicacy and thinning out at the border of the lesion. Benign dermoscopic network patterns are diffuse network pattern, patchy network pattern, structureless center pattern, globular center pattern, and pigmented-blotch center pattern. They can be found in DMN with a network predominantly thinning out at the border of the lesion.     

Clinical diagnosis of dysplastic melanocytic nevi: A clinicopathologic correlation

A prospective, community practice-based, clinicopathologic correlation was undertaken in 165 melanocytic nevi excised from a group of forty-three patients, each patient having previously had at least one clinically suspected and histologically confirmed dysplastic melanocytic nevus. Eighty-two percent of seventy-two lesions with histologic evidence of mild dysplasia had been diagnosed correctly as such clinically. The accuracy of clinical diagnosis of moderate dysplasia was low (20%); however, all cases of severe dysplasia with or without in situ melanoma were diagnosed correctly. In 75% of all cases in which dysplasia of any degree was diagnosed clinically, histologic evidence of dysplasia was found. In order to investigate further the clinical features of these nevi, 175 color enlargements of histologically confirmed dysplastic melanocytic nevi were examined. The following clinical features were found to be most common: ill-defined border (90%), irregularly distributed pigmentation (84%), maximum diameter greater than 5.0 mm (72%), erythema (64%), and accentuated skin markings (63%). Increasing darkness and confluence of pigmentation in these dysplastic melanocytic nevi correlated with increasing severity of dysplasia. We conclude that careful clinical examination of individual melanocytic nevi will separate severe dysplasia with or without in situ melanoma from low-grade (mild or moderate) dysplasia in a high percentage of nevi from patients with the dysplastic nevus syndrome. Clinical examination will yield a diagnosis of dysplasia in approximately 75% of nevi from such patients in whom histologic evidence of dysplasia is present. Clinical examination constitutes a practical and sufficiently reliable method for the assessment of melanocytic nevi in patients with the dysplastic nevus syndrome.     

Age distribution and histologic patterns of dysplastic nevi

A total of 676 dysplastic moles collected from 487 patients over a 1-year period were reviewed together with demographic data. The associated nevus in 642 cases (95%) had a superficial, or "acquired," pattern within the papillary dermis, in comparison with the nevus in the remaining 34 cases (5%), which showed a deep, or "congenital," pattern. The dysplasia was graded in severity as mild, moderate, or severe (on a scale of 1 to 3). When patients with mild to severe dysplastic melanocytic nevi were compared with those patients showing atypical intraepidermal melanocytic hyperplasia (also called in situ malignant melanoma) or early invasive malignant melanoma associated with dysplasia, a progression of ages was noted. The average ages in the five diagnostic groups were as follows: 34.8 years, mild dysplasia (group 1); 35.1 years, moderate dysplasia (group 2); 41.5 years, severe dysplasia (group 3); 44.4 years, in situ malignant melanoma (group 4), and 46.9 years, early invasive malignant melanoma (group 5). Statistical analysis revealed that the two younger groups differed significantly in age from the three older groups. Men and women had an equal proportion of acquired and congenital pattern nevi, but men were older in each category and had more severe dysplasia, a greater tendency toward truncal lesions, and more regressive changes. Biopsy of trunk lesions was done in 275 cases (80%), of extremity lesions in 60 cases (17%), and in head and neck sites in 9 cases (3%).(ABSTRACT TRUNCATED AT 250 WORDS)     

The histopathology of dysplastic nevi. Continued controversy

The histopathologic criteria used in the diagnosis of dysplastic nevi have been a source of controversy, as has the clinical significance of these lesions. Several dermatopathologists noted for their work on dysplastic nevi were asked to contribute responses to questions regarding the architectural and cytological criteria used to classify a melanocytic nevus as dysplastic, the terminology used to describe these lesions, and the role of dysplastic nevi as precursors of melanoma. Although no consensus has been reached regarding the cytologic features required for diagnosis of dysplastic nevi, there is substantial agreement regarding the architectural features of these lesions.