Although rare, congenital malignant melanoma (CMM) should be considered in the differential diagnosis of congenital skin lesions. We report a case of CMM in a 4-month-old infant presenting with an enlarging scalp mass, initially thought to be a hemangioma. Incisional biopsy of the lesion showed a compound congenital nevus with atypical cells suggestive of a proliferative nodule versus malignancy on histopathology. Subsequent excisional biopsy revealed malignant melanoma, and further workup confirmed extensive disease with distant metastases. Cytogenetic analysis of both the tumor sites showed highly abnormal karyotypes including pseudotetraploidy, telomere associations, and evidence of gene amplification, all consistent with malignancy. Fluorescence in situ hybridization demonstrated amplification of the MYC gene, with no copy number changes in CDKN2A (INK4/ARF), PTEN, or Cyclin D1. Our report details the cytogenetic and molecular studies of CMM, which provide insight into the biologic behavior of the lesions and may confirm diagnosis when histopathology is not determinant.
*Cedars-Sinai Medical Genetics Institute, Los Angeles, CA;
†Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, Cedars-Sinai Medical Center, Los Angeles, CA;
‡Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR;
§The Dermatology Group, West Orange, NJ;
¶Department of Pathology, Cedars-Sinai Medical Center, Los Angeles, CA; and
‖Plastic Surgery for Children, Santa Monica, CA.
Reprints: Krishna Singh, MD, Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, Cedars-Sinai Medical Center, 8635 W, 3rd St, Suite 160W, Los Angeles, CA 90048 (e-mail: firstname.lastname@example.org).
The authors declare no conflicts of interest.