Spitz nevus: a childhood lesion with alarming microscopic features to the unwary

A recently growing pink cutaneous nodule of the lower extremity in a three-year-old Caucasian girl was excised totally with a clinical presumptive diagnosis of “growing granulation tissue of undefined etiology”. The microscopic sections yielded highly characteristic features of a benign Spitz nevus of childhood. A highly cellular spindle cell lesion, without melanin pigmentation and prominent atypia, was noticed. Spitz nevi are distinctive melanocytic lesions of children (being rare in adults) with alarming cellular morphology to the unwary. These lesions are mainly symmetrical dermal and junctional (i.e. compound) nevi with epithelioid and spindle melanocytes having large nuclei with prominent nucleoli. The most important microscopic features are; symmetrical scanning power view, sharp demarcation, uniform maturation (zonation), epidermal hyperplasia, no high-grade atypia, few mitoses, no mitoses in deeper parts, and no subcutaneous tissue involvement. Some Spitzoid lesions present atypia and are, therefore, referred to as “atypical Spitz nevi” or “atypical Spitz tumors”. Also, there are rare malignant cases labeled as “Spitzoid melanoma” with microscopic similarities to these lesions mostly occurring in adulthood with epitheliod cells predominating rather than spindled cells. It is also important in difficult lesions to ask for a second opinion from expert dermatopathologists when indicated.