Eosinophilic globules in Spitz nevi: No evidence for apoptosis

Eosinophilic globules are commonly found in Spitz nevi and can be of help in the differential diagnosis with melanoma. Despite their use as a diagnostic marker, there are conflicting concepts concerning the mechanism of the formation of these globules. Because pyknotic nuclei are often present in the cells surrounding the globules, many believe that apoptotic cell death of keratinocytes and melanocytes is an important mechanism in their formation. We studied nine Spitz nevi containing 21 eosinophilic globules for apoptotic cell death around and within Kamino bodies using the TUNEL method (TdT-mediated dUTP-x nick end-labeling method). In none of the cases were positive cells seen in the vicinity of the globules. Single apoptotic cells were found only sporadically in the melanocytes of the neoplasms (one to four per section) and were scattered throughout the entire lesion. The absence of apoptosis-specific labeled cells in the vicinity of eosinophilic globules and the rare occurrence of positive stained cells in other parts of the tumors makes apoptotic cell death unlikely to be relevant in the formation of eosinophilic globules.