Distinguishing epithelioid blue nevus from blue nevus-like cutaneous melanoma metastasis using fluorescence in situ hybridization.
ABSTRACT Blue nevus (BN)-like cutaneous melanoma metastasis is a well-recognized variant of melanoma metastasis. These lesions may clinically and histologically simulate benign blue nevi. The histologic changes may be indistinguishable from conventional blue nevi or epithelioid blue nevi (EBN), a benign dermal-based melanocytic neoplasm with epithelioid morphology and heavily pigmented cytoplasm. Distinguishing BN-like cutaneous melanoma metastasis from benign conventional or EBN is important for staging and treatment. We evaluated a fluorescence in situ hybridization (FISH) assay using probes targeting 6p25 (RREB1), 6q23 (MYB), 11q13 (CCND1), and centromere 6 (Cep6) with previously determined criteria, to distinguish EBN and BN-like melanoma metastasis. Ten BN-like cutaneous melanoma metastatic lesions and 10 EBN were blindly evaluated with the above mentioned FISH probes. FISH enumeration and criteria for diagnosis of melanoma was as previously described. Nine of 10 BN-like cutaneous metastatic lesions showed significant aberrations and met previously established criteria for melanoma. None of the EBN cases showed evidence of significant copy number changes or met FISH criteria for a diagnosis of melanoma. FISH is an important diagnostic adjunct for melanocytic neoplasms. In this study, we show that a FISH assay targeting 6p25, 6q23, 11q13, and centromere 6 can distinguish EBN from BN-like metastatic melanoma with high accuracy. The test and the parameters previously established can perform with high sensitivity and specificity when dealing with this differential diagnosis.
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ABSTRACT: By integrating the clinical features of a skin lesion and its histological findings, dermatopathologists are usually able to correctly diagnose most skin disorders. However, situations often arise where clinical appearance and impression from a superficial histopathologic examination are misleading and may direct to a completely erroneous diagnosis. These pitfalls in diagnosis are most significant when they involve various tumors with a malignant potential. In these diseases, a misdiagnosis is likely to have serious medical consequences. It is important to be aware of these specific histological mimickers, because only then may the dermatopathologist be able to detect the subtle changes that lead to a correct diagnosis. Clinical–pathological correlation is also essential. Entities that are prone to misdiagnosis can generally be divided into three categories: skin malignancies that resemble reactive conditions or benign neoplasms; benign conditions that masquerade as malignancies; and tumors that may be mistaken for other types of cutaneous malignancies.Expert Review of Dermatology 01/2014; 7(6). DOI:10.1586/edm.12.56
Article: Cytogenetics of Melanoma: A Review[Show abstract] [Hide abstract]
ABSTRACT: Malignant melanoma is an aggressive cutaneous neoplasm whose incidence has continued to increase worldwide. Currently, histopathologic examination of specimens is the gold standard for the diagnosis and categorization of melanoma. Cytogenetic analysis represents a powerful, and currently underused, adjunct to traditional histologic examination in distinguishing nevi and melanomas. Chromosomal studies have shown that malignant melanomas often contain multiple chromosomal alterations, most commonly of chromosomes 1, 6, 7, 9, 10 and 11. These chromosomes often include genes within the MAPK molecular pathway, which is involved in the development and progression of melanoma. Fluorescence in situ hybridization (FISH) can detect a number of recurrent anomalies, and commercially available kits for melanoma detection have been devised. The utility of cytogenetics in melanocytic lesions at certain anatomic sites has been evaluated, including acral lesions, uveal lesions, and lymph node metastases. Recurring cytogenetic anomalies have been defined in various challenging histologic subtypes, such as desmoplastic melanomas and Spitzoid lesions. Cytogenetic analysis may also be used to provide supplementary information in prognostication, particularly in uveal melanomas. We provide a brief review of the molecular pathways found in melanoma and a summary of what is known and remains unknown regarding cytogenetic aberrations associated with malignant melanoma. Keywords: nevus, nodal nevus, blue nevus, cutaneous melanoma, desmoplastic melanoma, uveal melanoma, blue nevus-like melanoma, cytogenetics, FISH, fluorescence in situ hybridizationJournal of the Association of Genetic Technologists 10/2014; 40(4):209-218.
Current Problems in Surgery 12/2014; 51(12):478-520. DOI:10.1067/j.cpsurg.2014.11.004 · 1.42 Impact Factor