We do appreciate Dr. Torchia′s comments about our recent published article,1 suggesting new methods to optimize the diagnosis of suspect pigmented lesions featuring a parallel-ridge pattern.
Torchia et al suggest a diagnostic algorithm for these suspicious lesions. In their approach, the specimen should be initially split in two halves in order to process each one in a different way. However, we wish to point out that the split of the biopsy specimen would make impossible the evaluation of their architectural features,2,3 which nowadays constitute one basic aspect in the differential diagnosis of acral melanocytic lesions.
They also propose that transverse histologic sectioning of biopsy specimens of patients suspected of having acral melanoma can demonstrate more efficiently the diagnostic features. In fact, the transverse section method is a cheap and affordable tool, that allows examination of all the eccrine ducts contained in a given specimen, and consequently provides more exhaustive information.4 Nevertheless, this technique presents some disadvantages. One the one hand, process and evaluation of horizontal sections can be more complicated and requires technical experience. On the other, dermoepidermic junction (including granulous stratum) is poorly represented.5 These two factors could easily lead to misdiagnose melanoma thickness, and secondarily tumor staging. In view of these considerations, we do not consider that serial horizontally cross-sectioning technique is the most adequate tool in the diagnosis of pigmented lesions. However, in future its use could be considered in some cases whenever tumor thickness was previously evaluated with specific image techniques such as in vivo confocal microscopy.6,7
We thank Dr. Torchia for his contribution, as he enrich our article and raise new issues and ideas for future studies.
