Spitz nevi in African Americans: A retrospective chart review of 11 patients.

BACKGROUND: Spitz nevi are benign melanocytic neoplasms that typically present as rapidly growing solitary lesions on the head, neck, or lower extremities. Very rare reports have been described in African Americans. METHODS: A single-institution 29-year retrospective review of African American patients diagnosed with Spitz nevi was thoroughly analyzed in order to characterize these rare clinical and histopathologic presentations. RESULTS: Eleven African Americans with spitzoid lesions were identified. Seven (64%) cases were in pediatric patients and nine (82%) were in females. Most lesions were hyperpigmented (73%) and elevated (82%). Six (55%) were compound Spitz nevi, three (27%) were dermal Spitz nevi, and two (18%) were junctional Spitz nevi. Two lesions had more than one atypical feature. Histopathologically, common features were symmetry, sharp circumscription, pagetoid spread (55%) with most being centrally, predominance of epithelioid cells (64%), Kamino bodies (45%), slight pigmentation (46%), maturation of dermal component with depth, and lack of subcutaneous fat involvement or ulceration. Excision was performed on all patients and there were no recurrences although follow-up was limited. CONCLUSION: Awareness of the possibility and various presentations of Spitz nevi in African Americans will help prevent misdiagnosis.

Nuclear and cytoplasmic features in the diagnosis of banal nevi, Spitz nevi, and melanoma.

BACKGROUND: Many authors have described cytologic features in a variety of melanocytic lesions but, to our knowledge, a statistical analysis of sensitivity, specificity, and overall accuracy of these features alone or in combination has not been performed. OBJECTIVE: We sought to determine the diagnostic value of nuclear and cytoplasmic characteristics in the diagnosis of melanocytic lesions via multivariate statistical analysis. METHODS: This is a retrospective observational study conducted on 300 melanocytic lesions. We evaluated a series of distinctive features; subsequently a multivariate model was used to determine sensitivity and specificity. RESULTS: Major features that favor a diagnosis of melanoma include: pleomorphism with enlarged nuclei, mitotic figures, notching/corrugation of the nuclear envelope, and peppered moth nucleus. Features with intermediate value include: solid hyperchromasia, vesicular nucleus with single round nucleolus, and nuclear/cytoplasmic ratio greater than 4:1. LIMITATIONS: Limitations of this study include its retrospective nature, and the reliance on the original diagnostic classification of each neoplasm. CONCLUSION: Our data suggest that some nuclear alterations have greater value in the diagnosis of benign and malignant melanocytic lesions.

In vivo confocal scanning laser microscopy of pigmented Spitz nevi: comparison of in vivo confocal images with dermoscopy and routine histopathology.

BACKGROUND: Spitz nevus is a benign melanocytic lesion sometimes mistakenly diagnosed clinically as melanoma. OBJECTIVE: Our aim was to evaluate in vivo reflectance-mode confocal scanning laser microscopy (CSLM) aspects of globular Spitz nevi and to correlate them with those of surface microscopy and histopathology. METHODS: A total of 6 Spitz nevi, with globular aspects on epiluminescence observation, were imaged with CSLM and subsequently excised for histopathologic examination. RESULTS: A close correlation among CSLM, epiluminescence, and histopathologic aspects was observed. Individual cells, observed in high-resolution confocal images, were similar in shape and dimension to the histopathologic ones. Lesion architecture was described on reconstructed CSLM images. Melanocytic nests corresponded to globular cellular aggregates at confocal microscopy and to globules at epiluminescence observation. Melanophages were clearly identified in the papillary dermis both by confocal microscopy and histopathology. CONCLUSION: In vivo CSLM enabled the identification of characteristic cytologic and architectural aspects of Spitz nevi, correlated with histopathology and epiluminescence microscopy observation.

Measurement of the maturation parameter by using computer-assisted interactive image analysis may be helpful in the differential diagnosis between compound Spitz nevus and malignant melanoma.

The so-called maturation parameter (MP) (that is, the ratio of the mean nuclear areas in the deep portion and in the superficial portion of a tumor) was measured and calculated using a computer-assisted interactive image analysis system in 29 compound Spitz nevi (SNs) and 37 primary invasive cutaneous malignant melanomas (MMs), of which 16 and 14 lesions, respectively, measured up to 1 mm in Breslow thickness (that is, thin). The MPs of the SNs and MMs were found to be 0.37-0.89 (mean +/- SD, 0.64 +/- 0.1) and 0.81-1.16 (mean +/- SD, 0.96 +/- 0.1), respectively (p < 0.001). The MPs of the subgroups of thin SNs and MMs were 0.56-0.87 (mean +/- SD, 0.67 +/- 0.1) and 0.86-1.10 (mean +/- SD, 0.98 +/- 0.1), respectively (p < 0.001). Most of the SNs and MMs had MP values of < 0.81 and > 0.89, respectively. This pattern of distribution prevailed in the subgroup of thin lesions. Thus, the previously shown difference in MPs between SN and MM for thicker lesions (> or = 1.0 mm) was demonstrated in this study in thin lesions (< or = 1.0 mm) as well. Although a relatively small area of overlap in MP values exists between compound SNs and MMs, including the thin ones, below this area the lower the MP value the more likely the diagnosis is SN, and vice versa.

Nuclear pseudoinclusions in melanocytic naevi and melanomas.

Melanocytes in melanocytic naevi and melanomas can display great variation. The presence of nuclear pseudoinclusions (NPI) is said to be useful in the histological and cytological differential diagnosis of malignant melanoma. The prevalence and characteristics of NPI in a series of 493 naevi and 50 melanomas are described. NPI were found in 31% of adult naevi, 30% of congenital naevi from children, 42% of Spitz naevi, 20% of dysplastic naevi, and 56% of melanomas. The presence of NPI is not a reliable criterion for differentiating melanoma from benign melanocytic lesions, although it is useful in distinguishing melanocytic from non-melanocytic tumours.

AgNOR area measurements differentiate benign and malignant melanocytic lesions more accurately than simple counting.

Comparison of argyrophilic nucleolar organizer region (AgNOR) counts has been found to yield statistically significant differences between benign and malignant conditions albeit with considerable overlap. In this study we compared the size of AgNORs and the nuclear areas, as well as the AgNOR count in 23 benign melanocytic lesions and 9 melanomas. Of these parameters, the ratio AgNOR area/nuclear area was found to be the main discriminating factor between melanoma and all the other benign groups studied, with p values of < 0.01 and no overlap. Next to it was the nuclear area, which in our study gave significant differences between the groups evaluated. The total AgNOR area and the largest AgNOR gave results comparable to the simple AgNOR counting in all groups studied, except in Spitz nevus, in which the AgNOR counts were less significant than the other parameters (p = 0.0420). We conclude that the ratio AgNOR area/nuclear area discriminates benign from malignant melanocytic lesions better than AgNOR counts or other parameters studied.