In the French Bulletin of the Society of Dermatology and Syphilology for March 3, 1910, Darier and A. Civatte¹²³ confronted the enigma of "Nevus or nevo-carcinoma in a newborn" as the lesion presented itself in the form of a red papule on the nose of an 8-month-old. The lesion, which had appeared when the child was 6 months old, grew rapidly, supposedly enlarging every day until the time that it was seen by dermatologists, who noted that it was dome-shaped, papillomatous, 1.0 cm in diameter, and raised 2.0–3.0 mm above the surface of the skin. For the examiners, the lesion was too red, too hard, and too rapid in growth to be deemed a nevus. In short, they were uncertain about the diagnosis, but favored a lymphosarcoma. Sections of tissue from a biopsy specimen also showed conflicting findings; some changes were compatible with lymphosarcoma and others with a nevus. The cells that made up the "tumor" seemed to originate from the epidermis; they were fusiform with a large clear nucleus. Those cells infiltrated the entire dermis and were disposed both as solitary units and in small compact masses. Because the large cells looked most like ones of connective tissue, the differential diagnosis by microscopy was fibrosarcoma, lymphosarcoma, or alveolar-cell sarcoma. In many sections of tissue, however, groups of cells in the papillary dermis resembled nests of a nevus. This disparity, namely, features in some sections of a sarcoma and in others of a nevus, left the authors baffled. They could not decide, with surety, whether the tumor was benign or malignant.

At this juncture in their article, Darier and Civatte recalled a lesion reported on by Kyrle in "a recent work" (for which no reference was given) in which histopathologic findings very similar to those in their 8-month-old with a red papule on the nose were described.

In brief, Kyrle noted cells like those of lymphosarcoma in what otherwise was a nevus. He did not concern himself with the matter of whether the lesion was benign or malignant, but he implied it was benign, to wit, a "simple nevus." By contrast, Darier and Civatte wrestled with the issue of the fundamental character of the neoplasm borne by the 8-month-old and were uncertain about the true nature of it. Because so many of the constituent cells were "malignant looking," they naturally were inclined to consider the neoplasm to be malignant. This is how they phrased the conundrum they were unable to resolve: "In favor of the hypothesis that the tumor is malignant we have the rapid growth and the impressive development of it. However, the convincing arguments in favor of malignancy, namely, spread to lymph nodes or metastases to the skin or even simple pigmentation, are lacking. We have all of the fears about malignancy, but no certainty of it. The findings prompt us to lean toward malignancy but we are not sure." In sum, Darier and Civatte, soon after Kyrle, described a proliferation of melanocytes, many of the cells of which "look malignant," but which behaved in a benign way. Although they were unsure about whether the "tumor" was benign or malignant, as they acknowledged in the title of their piece ("Nevus or nevo-sarcoma in a newborn"), they inclined toward malignancy based mostly on cytopathologic attributes ("malignant-looking cells").