Balloon cell melanoma is a rare subtype of melanoma that is underrecognized clinically and is challenging to diagnose on histologic studies.Objective
To further characterize the clinical, dermoscopic, and histopathologic features of balloon cell melanomas and their correlation to gene expression.Design, Setting, and Participants
Case series of 2 patients with balloon cell melanoma whose medical records were retrieved from the database of Thomas Jefferson University Dermatopathology Center in Philadelphia, Pennsylvania. Both cases had been referred to the institution’s dermatopathology laboratory and provided complete data on clinical, dermoscopic, and histopathologic findings and gene-expression profiles.Main Outcomes and Measures
Dermoscopic findings, histopathologic findings, and results of gene expression tests.Results
In the 2 patients included, translucent hypopigmented areas on gross examination and a translucent white-gray veil and dull yellow globules on dermoscopic examination correlated with the balloon cell melanocytic region demonstrated on histologic studies with hematoxylin-eosin stain. Specifically, dull yellow globules corresponded to the balloon cell melanocytic nests. Both lesions presented with a second, morphologically distinct population of melanocytes, common in balloon cell melanocytic neoplasms. In both cases, a prominent junctional component that consisted of cells demonstrating ample clear-to-granular cytoplasm and a central nucleus were present. Cytologic atypia was minimal to lacking in both cases, and architectural disorder served as a better clue to the diagnosis. Findings of a gene expression profiling test corroborated the diagnosis in both cases.Conclusions and Relevance
Balloon cell melanomas may present with characteristic clinical and dermoscopic findings, and a gene expression profiling test may provide additional useful diagnostic information in cases that are difficult to interpret.