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Dermatopathology: Practical & Conceptual January - March 2001
Evolution In Thinking: Criteria for Histopathologic Diagnosis of Melanoma, 1947–2000: A Critique in Historical Perspective
Mary Aldrene L. Tan, M.D.
A. Bernard Ackerman, M.D.
Becker and Obermayer
Ormsby and Montgomery
Percival, Montgomery, and Dodds
Pinkus and Mehregan
Clark and Mihm
Price, Rywlin, and Ackerman
Pinkus and Mehregan
Ackerman and Su
Kamino and Ackerman
Domonkos, Arnold, and Odom
Roses, Harris, and Ackerman
Okun, Edelstein, and Fisher
Weedon and Strutton
Elder and Elenitsas
Langley, Fitzpatrick, and Sober
Dewan and Ackerman
Farmer and Hood
"At scanning magnification, radial growth phase melanoma of the superficial spreading type is characterized by nested and single-cell spread of epithelioid malignant melanocytes within a normal or slightly hyperplastic epidermal layer. Pagetoid cells resemble those of mammary and extramammary Paget disease and are present in all layers of the epidermis, including the stratum granulosum."
"At slightly higher magnification, irregularities in the size and shape of nested malignant melanocytes are encountered . . . "
" . . . Superficial spreading melanoma is typified by non-uniform, irregular, enlarged nests of atypical cells. Nests in superficial spreading melanoma may be observed in all layers of the epidermis in a manner similar to the pagetoid spread of individually malignant melanocytes."
"At high-power magnification, superficial spreading melanoma cells are characteristically epithelioid in shape, with visible, variably pigmented, granular cytoplasm. Nuclei are large, irregular in size and shape, and contain prominent, often eosinophilic nucleoli. An important feature of melanoma nuclei, with respect to differentiating them from Spitz nevus cells, which also may have prominent nucleoli, is the presence of coarsely clumped background heterochromatin and irregularly thickened nuclear membranes. The cytoplasm of melanoma nuclei is coarsely granulated, as opposed to the finely vacuolated cytoplasm in Spitz nevi. Moreover, dusty or muddy melanization may be observed in superficial spreading melanoma . . ."
Philadelphia: WB Saunders Company, 1995:2467.
Apart from the presence of pagetoid melanocytes in pagetoid pattern within the epidermis, none of the findings mentioned by Murphy enable melanoma to be distinguished from some examples of Spitz's nevus. The claim that the "cytoplasm of melanoma is coarsely granulated, as opposed to the finely vacuolated cytoplasm in Spitz nevi" is without foundation.
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