In 1975, Helwig, in a lecture devoted to "Neoplasms of the skin and malignant melanoma," recounted his experience at the Armed Forces Institute of Pathology (AFIP) with 23 patients, all of whom were 14 years of age and younger, who had a primary cutaneous melanoma and proven metastasis from it. Excluded from the series were melanomas associated with large congenital nevi and cellular blue nevi. One year later, Helwig published his findings by conventional microscopy and summarized them in these words:³⁰

Although the 23 neoplasms reported on by Helwig doubtlessly were melanomas because all of them gave rise to metastasis, they cannot be identified with surety as melanomas or be distinguished from benign juvenile melanomas on the basis solely of the histopathologic criteria offered by him in the preceding quotation. "Junction change," known also as "junctional activity" of melanocytes, was a phrase coined by Allen and invoked often by pathologists worldwide in those days, but it had no more meaning then than it does today. In short, "junction change" is as unhelpful for diagnosis and differential diagnosis of benign and malignant proliferations of melanocytes, and differential diagnosis of them, as ill-conceived descriptive phrases like "atypical melanocytic hyperplasia," "moderately severe melanocytic dysplasia," and "pagetoid melanocytic proliferation."

Helwig showed photomicrographs of only two of the 23 melanomas, namely, of Case 20 (Fig. 7A–D) and Case 23. The primary melanoma in Case 20 was pictured at scanning magnification (his Figure 5) and at high magnification (his Figure 6) with a comment in the legend to the latter to the effect that "multinucleated giant cells and epithelioid cells [were] surrounded by stroma and corium." In the text, Helwig also called attention to the presence in some of these melanomas of melanocytes with spindle and/or epithelioid shapes and of melanocytes that were giant and multinucleate. This is what he said: "In a few of the lesions, at least a substantial part of the cells were spindle and/or epithelioid in shape. The cells tended to be clustered or grouped, and giant and multinucleated epithelioid cells with 2 or more nuclei were noted (Figs. 5–8). Especially in the more superficial areas, the cells seemed to show a relationship with the stroma." The metastasis to a lymph node from the primary melanoma in Case 20 consisted of large aggregations of melanoma within the parenchyma. The melanoma pictured at scanning magnification in Helwig's Figure 5 resembles very closely what he referred to as spindle and epithelioid cell nevus (benign juvenile melanoma), and the cytologic features of the constituent melanocytes as shown in his Figure 6 taken at high magnification also resemble very closely those of spindle and epithelioid cell nevus. That this neoplasm is a melanoma and not a spindle and epithelioid cell nevus became obvious by virtue of the metastasis from it to a lymph node pictured in Helwig's Figures 7 and 8. Helwig advised in a legend to his Figure 8 that the neoplastic melanocytes shown in the metastasis are "atypical multinucleated giant cells and epithelioid cells" like those of a spindle and epithelioid cell nevus.