Dermoscopy of apocrine hidrocystomas: a morphological study

Background: The dermoscopic morphology of apocrine hidrocystomas remains to be elucidated.

Objective: To evaluate the morphological findings of apocrine hidrocystomas under dermoscopic observation.

Methods: Dermoscopic examination of 22 cases of apocrine hidrocystomas was performed to evaluate specific dermoscopic criteria and patterns.

Results: The most frequently occurring dermoscopic features were found to be: (i) A translucent to opaque, homogeneous area which occupies the whole lesion in all apocrine hidrocystomas (100%). The colour of this homogeneous area was skin-colored in 31.8% of our cases; yellow, in 31.8% and blue, in 22.7% of apocrine hidrocystomas. (ii) Vascular structures were identified in 81.8% of our cases; arborizing vessels, in 68.2% and linear-irregular vessels in 9.1% of our cases; and (iii) Whitish structures were identified in 22.7% of the lesions. The results of our study reveal that the presence of a homogeneous area that occupies the whole lesion and arborizing vessels is the most common dermoscopic pattern in apocrine hidrocystomas (68.2%).

Conclusion: Apocrine hidrocystomas, above all in its pigmented variant, may represent a dermoscopic pitfall, being difficult to differentiate clinically and dermoscopically from basal cell carcinomas.