Metastasis of a Surgically Excised Melanoma In Situ

ABSTRACT Melanoma in situ (MIS) is considered a noninvasive precursor to malignant melanoma and is defined as abnormal melanocytes that are confined to the epidermis without evidence of invasion through the basal membrane and into the deeper dermis. It is often referred to as Stage 0 melanoma. MIS is thought to have no metastatic potential. However, several reports have shown that occult invasive disease may be found upon further testing of pathologically unequivocal MIS. In addition, several risk factors contribute to the upstaging of an MIS. We present a case of a patient who was diagnosed with MIS who underwent excision of the primary lesion. Although the pathology report of the excision revealed negative margins, he was later found to have metastatic lesions to several lymph nodes, his parotid gland, and his brain. This resulted in extensive medical treatment that the patient did not originally anticipate.