Dermatoscopia de la disqueratosis pagetoide palmar

Approach to the so-called "Invisible Dermatosis": When Subtle Histopathological Findings Guide Diagnosis

ABSTRACT

Invisible dermatosis is a concept that can be applied either to clinical or histopathological findings. We will focus on the dermatopathological aspect of this invisible dermatosis that can be seen as dermatosis with subtle histopathological findings that are mandatory to known to stablish the diagnosis. With a proper approach facing in depth the different skin layers from stratum corneum to subcutaneous tissue combined with some especial stains, special investigations and mostly a proper clinicopathological correlation, the problem of missing out a diagnosis can be decreased. We will review the general aspects for diagnosis and the peculiar findings of an in-depth review of them because it is important to note that minor changes on a skin biopsy do not mean it is disease free. We will review classic clues, we will add some new useful ones, and we will also provide a guide on the special stains helpful, such as periodic acid-Schiff when facing fungi, orcein-Giemsa and van Gieson when altered elastic fibers are suspected, or Pearl and Masson Fontana when an altered skin pigmentation is suspected.

Pagetoid dyskeratosis with a palmar localization: Rapid resolution following biopsy

BACKGROUND

Pagetoid dyskeratosis (PD), which is found in more than 2% of skin biopsy specimens, is accepted as a histopathological finding reflecting the abnormal keratinization process. However, to date, only a limited number of cases have been described to have brown pigmentation on the hands, triggered by friction, and present with pagetoid dyskeratosis as the only sign on histopathology and a parallel ridge pattern on dermoscopy.

AIM

To present and discuss the typical clinical, histopathological, and dermoscopic features of pagetoid dyskeratosis, and to draw attention to the spontaneous resolution following biopsy.

PATIENT

We present a case of pagetoid dyskeratosis with a palmar localization, which rapidly resolved following biopsy, in a patient with no history of friction.

RESULTS

PD is the only important histopathological finding in typical irregular pigmented lesions located in the hand. PD should also be considered in the differential diagnosis of lesions that show parallel ridge pattern on the hand. Two weeks after the biopsy, disappearance of the lesion may be due to the effect of inflammatory response revealed by biopsy.

CONCLUSIONS

Although the cause of this condition is not yet fully understood, most cases being associated with friction or rapid spontaneous resolution following biopsy, as in the current case, may indicate the reactive nature of the lesion. Further researches are required to be clarify etiology of PD.