Metastatic Melanoma with Balloon Cell Changes: An Electron Microscopic Study

Abstract
A [human] case of metastatic balloon cell melanoma is presented. The balloon cells are ultrastructurally characterized by the presence of numerous cytoplasmic vacuoles and abnormal melanosomes, which confirm their melanocytic origin. The study supports the concept that the cytoplasmic vacuoles represent grossly dilated melanosomes. The value of EM examination is emphasized to distinguish these lesions from other malignant cell tumors.