In 1966, Skov-Jensen and coworkers reported on two children with melanoma, a 12-year-old girl with "malignant melanoma in the perineal region"²⁴ who developed metastasis to the right inguinal lymph nodes and died nine months later of widespread metastatic melanoma, and a 2-year-old boy who had a melanoma on the thigh thought clinically to be a pyogenic granuloma and that metastasized to an inguinal lymph node. That boy was said to be alive five years later and with no evidence of metastatic disease. Photomicrographs of the neoplasms in both children were shown, including metastases from them, but all of them are shown at such high magnification that little information of consequence can be gleaned from them. The authors also presented a detailed review of the literature concerning 43 examples of melanoma in children reported on until that time, and came to the conclusions that follow:

Also in 1966, Zwaveling and associates wrote about a 6-year-old who, for a year and a half, had a lesion that was enlarging on a toe of the right foot.²⁵ By the time the child was examined by a physician the tumor was 2.0 cm by 2.0 cm and bleeding. Sections of tissue from the biopsy specimen showed a "melanocarcinoma cutis." Two years and five months later, evidence histopathologically of metastasis of melanoma was discovered in lymph nodes in the right groin. The authors made these recommendations for management:

Two years later, in 1968, Saksela and Rintala, in an article about "Misdiagnosis of prepubertal melanoma: Reclassification of a cancer registry material,"²⁶ called attention to what they thought to be a disproportionate number of nevi diagnosed as prepubertal melanoma in children. Those colleagues studied 20 children 14 years of age or younger entered in the Finnish Cancer Registry with a diagnosis of melanoma during the period between 1954 and 1963. In 17 cases, sections of tissue were available for review, and based on it, nine lesions were reclassified as spindle and/or epithelioid nevi, two as malignant melanomas, two as cellular blue nevi, two as compound nevi, and two as neoplasms other than melanoma. The authors stated that they adhered strictly to "the differential diagnostic criteria of epithelioid and/or spindle cell nevi ("juvenile melanomas") proposed by Allen and Spitz." Of the two melanomas, one occurred in the axilla of a 14-year-old boy in whom a "small mole" had been removed from the back two years previously. The lesion in the axilla was thought to be a metastasis from that lesion and nine months later the child died from metastases of melanoma. The other melanoma occurred on the foot of a two-year-old girl and was said to have been noticed "one year previously," that is, when the child was one year of age. Abnormal melanocytes of that neoplasm subsequently metastasized to inguinal lymph nodes. At the time the article by Saksela and Rintala was published, however, the child was reputed to be well.

Predicated on their experience, Saksela and Rintala made these comments about the vagaries histopathologically of juvenile melanoma and malignant melanoma: