In brief, both Pack and Spitz were very much alert to a melanocytic neoplasm in children that they thought was indistinguishable histopathologically from malignant melanoma in adults, but that in their experience nearly always behaved in benign fashion. The peculiar behavior was attributed by them to the fact that hormones released at puberty were not yet at play; both of them believed that the very same neoplasm would behave differently before and after puberty, that is, it would "transform" from benign to malignant consequent to a rush of hormones.

The misperceptions of Pack and of Spitz could have been avoided had they been equipped with reliable criteria for clinical and histopathologic diagnosis of melanocytic nevi and of melanoma. But they were not. The melanocytic neoplasm that Pack called prepubertal melanoma and Spitz named juvenile melanoma was, in fact, a type of melanocytic nevus that fulfills all of the essential criteria, clinical and histopathologic, for a benign neoplasm and, that being the case, should have been distinguishable readily, in most instances, from a malignant melanoma, which, as its name denotes, fulfills the fundamental criteria, clinical and histopathologic, for a malignant neoplasm. But no such criteria ever were set forth by Pack or Spitz or Allen. And for that reason, confusion triumphed—and continued to reign in subsequent publications by them and by others—and for the same reason, and that remains the case today.

There can be no doubt that in 1948 Spitz misinterpreted completely the changes in sections of tissue of the nevus that now is known for her eponymically. Instead of identifying it as a particular kind of nevus, she insisted it was a malignant melanoma that exhibited features by conventional microscopy which were indistinguishable, according to her, from those of malignant melanoma in adults. One reason for her error was her lack of familiarity with dermatology; the photographs of the clinical lesions shown by her at the outset fulfill criteria for benignancy, that is, the lesions are symmetrical and sharply circumscribed. Another reason may be inferred from the many photomicrographs that accompany her article, none of which were "shot" at scanning magnification. In short, Spitz went headlong down the primrose path of equating cytologic atypia and mitotic figures with malignant neoplasia and concluding, therefore, that the proliferation of melanocytes she was scrutinizing was a true melanoma. Had she understood the importance of architectural pattern and, in particular, silhouette, which is the morphologic representation of the biologic behavior of a neoplasm, she might have come to a different, accurate diagnosis, namely, of a nevus. None of this gainsays the reality that some Spitz's nevi simulate melanoma histopathologically and that no histopathologist engaged seriously in the realm of diagnosis of melanocytic neoplasms, no matter how able the histopathologist and how reliable the criteria for diagnosis employed, has not fallen victim to that trap, namely, misdiagnosis of Spitz's nevus as melanoma and vice versa.

Regrettably, Spitz,^7,9 Allen,^8,18 and Allen and Spitz¹² never "'fessed up" to the mistaken interpretation of Spitz in her original article. In subterranean fashion, Allen, even as late as the 1990s, pretended that Spitz and he had gotten it right the whole time and, from the very beginning, had recognized the nevus for what it is.⁴⁶ That lack of intellectual rigor was not a boon to students who struggled to fathom the essential nature of the problem. What should have been communicated is that so-called prepubertal melanoma, melanoma in childhood, and juvenile melanoma is not related, in any way, to malignant melanoma, but is simply one of many types of melanocytic nevus.