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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
"The decision as to whether or not a given lesion is to be diagnosed an active junctional nevus or a melanocarcinoma must, when juvenile melanomas are excluded, depend on this single fact: the presence or absence of dermal invasion. It is to be stressed, however, that awesomely little evidence of dermal downgrowth of malignant cells is required for the diagnosis of melanocarcinoma, as opposed to junctional nevus. Often, isolated or clusters of invading cells are recognized among the subepidermal lymphocytes by their circular shape and abundant spongy cytoplasm, finely sprinkled with granules of melanin. They are to be distinguished particularly from histiocytes or reticulum cells. The subepidermal zone of lymphocytes is usually present in both the activated junctional nevus and the superficial melanocarcinoma."
) Allen AC. The Skin. A clinicopathologic treatise. St. Louis: The C. V. Mosby Company, 1954:868.
Fig. 4 Our diagnosis and comment: Melanoma
The term "active junctional nevus" is wrong in all respects; activity cannot be observed through a microscope, the abnormal melanocytes are not situated only at the dermo-epidermal junction, and the lesion is not a nevus. Allen acknowledged that the neoplasm is a melanoma by stating, " . . . this lesion is equivalent to a melanocarcinoma
In actuality, however, melanoma is a sarcoma, not a carcinoma.
The idea of identifying "invasion" on morphologic grounds is wholly without justification; a compound nevus, such as Spitz's, is no less invasive, as judged morphologically than a melanoma of equal thickness. In fact, a Spitz's nevus often is more invasive biologically because of its capability for more rapid growth than melanoma, evidenced by readily discernible mitotic figures in many Spitz's nevi. In actuality, histopathologists make a determination of invasion based on reasoning in post hoc ergo propter hoc fashion: if a neoplasm is deemed to be benign, for example, a Spitz's nevus, it is said not to be invasive, but if a neoplasm of the same thickness is thought to be malignant, for example, melanoma, it is then claimed to be invasive.
In short, Allen provided no criteria for distinguishing melanoma from Spitz's nevus.
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