Relapsing eruptive multiple Spitz nevi or metastatic spitzoid malignant melanoma?

An unusual case of multiple relapsing Spitz nevus (SN) in a patient with pseudohypoparathyroidism is described. It arose initially as a single lesion, and recurred twice as multiple agminated lesions that maintained the same histological pattern as the original SN. Nevertheless, the clinical behavior led to a diagnosis of metastasis from malignant melanoma at another medical institution. This case emphasizes the need for relying on accurate histopathological criteria to distinguish SN from malignant melanoma if inappropriate and detrimental therapeutic procedures are to be avoided.