The distinction between melanoma and its most important simulant, Spitz nevus, is usually made on microscopically. We point out "consumption of the epidermis" (COE) as an additional diagnostic criterion. We defined COE as thinning of the epidermis with attenuation of the basal and suprabasal layers and loss of rete ridges in areas of direct contact with neoplastic melanocytes. We analyzed 102 unequivocal melanomas and 125 unequivocal Spitz nevi for the presence of COE. COE had not been used in arriving at the diagnosis of these cases because we were unaware of the criterion at the time that the cases were first evaluated. COE was found in 88 of 102 (86%) of melanomas but only 12 of 125 (9.6%) of Spitz nevi (P < 0.001). We then looked for COE in an independent set of 61 ambiguous melanocytic lesions with overlapping histopathologic features that could not be classified unequivocally as Spitz nevus or melanoma. The cases were analyzed by comparative genomic hybridization (CGH) for aberration patterns suggesting a benign or a malignant process, based on previous studies. COE was found in only 6 of 42 (14%) of the ambiguous cases in which CGH suggested a benign process and 14 of 19 (74%) of the ambiguous cases in which CGH suggested melanoma (P < 0.001). Our data suggest that COE is a useful criterion in the evaluation of melanocytic neoplasms. Because COE was frequently found at the edges of ulcers in the majority of ulcerated melanomas, the thinning of the epidermis in COE may represent an early phase of ulceration. This may prove to be important in distinguishing ulceration due to an effect of the tumor from ulceration due to trauma, which would be expected not to have the same prognostic import. Future studies are required to analyze the prognostic value of COE itself.
"Additionally a small number perhaps 5% of spitz nevi without 11p gain may also have this same HRAS mutation . Spitz nevi most likely to harbor 11p gains are those that are large and bulky tumors with an infiltrative pattern with desmoplasia and dispersion to single cells at the base . Additional unique features of Spitz nevi include frequent tetraploidy, which is characteristic of approximately 5% to 10% of spitz nevi . "
[Show abstract][Hide abstract] ABSTRACT: Melanocytic neoplasms with spitzoid features including spitz nevi, spitz tumors and spitzoid melanomas are commonly encountered in the practice of dermatopathology. Although many cases can be accurately diagnosed on the basis of morphology and histology, a significant number of cases may be difficult to accurately classify. Several studies have now shown that chromosomal copy number aberrations are typical of melanoma while present in only a small percent and to a limited degree in spitz nevi. In this study, we correlated the clinical, histologic and array CGH findings of 10 spiztoid melanocytic neoplasms. Our study shows that the clinical and histologic changes correlate well with the molecular findings by array CGH. Further that array CGH can be used to help classify and predict behavior of spitzoid melanocytic neoplasms. A limited variety of copy number aberrations including gains of 11p and much more rarely 7q may be seen in spitz nevi. Additionally in this report we present the first case of a typical spitz nevus with copy number gains involving both 7q and 11p. Conversely, melanomas with spitzoid features typically have multiple chromsomal copy number aberrations involving a variety of loci. A smaller number of chromosomal aberrations, possibly a single aberrant locus, may be present in spitz tumors, but their presence may predict more aggressive behavior.
International journal of clinical and experimental pathology 01/2010; 3(6):593-9. · 1.89 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Primary cilia in neurons have often been regarded as rare, vestigial curiosities. However, neuronal cilia are now gaining recognition as ubiquitous organelles in the mammalian brain, raising speculation about what their functions may be. They might have some features tailored for the nervous system and others that serve needs shared by a spectrum of other cell types. Here we review clues from the literature and present new data supporting several possibilities for the significance of neuronal cilia. Our immunocytochemical results show regional heterogeneity in neuronal cilia. Brain regions nearer to the cerebral ventricles had longer cilia, suggesting that they might sense chemicals such as peptides, originating from cerebrospinal fluid. In mutant Tg737(orpk)mice, most brain regions appeared to be missing cilia. The importance of intraflagellar transport proteins establishes a functional link between neuronal cilia and other primary cilia.
Cell Biology International 02/2004; 28(2):111-8. DOI:10.1016/j.cellbi.2003.11.008 · 1.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cleft formation has been postulated as a clue to the histopathological diagnosis of malignant melanoma (MM). The frequency and reliability of clefts as a diagnostic criterion remain to be determined. We reviewed 503 cases of histologically proven MM searching for clefting between the epidermal layer and underlying MM. Cleft was defined as a separation of at least 0.3 mm in length. Conspicuous cleft formation was present in 120 (24%) of 503 MMs. The presence of clefts was not associated with age or sex of the patients, but showed a slight predilection for the back, a slightly higher prevalence in superficial spreading type of MM and for tumors with a Breslow thickness between 1 and 2 mm. Morphologically, clefts could be separated in 3 different types: linear (37.5%), single-nest (10.9%), and multi-nest (51.6%). In comparison, among 939 benign melanocytic lesions including 100 Spitz or Reed nevi, only 9 exhibited clefts longer than 0.3 mm (< 1%). One was an atypical compound nevus; all others were Spitz nevi, with the majority exhibiting an arched morphology above 1 or 2 large round nests. The relative frequency of cleft formation allowed a highly significant differentiation between MM and benign melanocytic lesions. Clefts are a reliable diagnostic criterion in favor of MM.
Human Pathlogy 05/2005; 36(4):412-5. DOI:10.1016/j.humpath.2005.02.005 · 2.77 Impact Factor
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