1 - Milia-like cysts
2 - Comedo-like openings
3 - Exophytic papillary structures
4 - Red Lacunas
5 - Leaf-like areas
6 - Central White patch




Milia-like cysts

This typical example of seborrheic keratosis is characterized by numerous milia-like cysts (arrows) and few comedo-like openings

Acanthotic seborrheic keratosis with several milia-like cysts (arrows) and few, variously shaped comedo-like openings

This acanthotic type of seborrheic keratosis reveals rare, variously sized horn pseudocysts corresponding to milia-like cysts






Comedo-like openings

This heavily pigmented seborrheic keratosis is characterized by numerous comedo-like openings (arrows). Only few milia-like cysts can be recognized.

The comedo-like openings (arrows) of this seborrheic keratosis are only faintly colored, in contrast to the dark-stained comedo-like openings of the previous example. In addition, note few, large milia-like cysts in the lower left part of this lesion.

Note few comedo-like openings and also some horn pseudocysts in this seborrheic keratosis






Exophytic papillary structures

This papillomatous dermal nevus (Unna nevus) is characterized by several, closely aggregated exophytic papillary structures. Nearly identical papillations are commonly found also in seborrheic keratoses.

Within the center of this Clark nevus several exophytic papillary structures are recognized

This is a typical example of a papillomatous dermal nevus (Unna nevus) exhibiting a pronounced papillomatous appearance that corresponds to exophytic papillary structures






Red Lacunas

Stereotypical example of hemangioma with numerous red-bluish lacunas

Angiokeratoma with several red-violaceous to blue-black lacunas due to thrombosed vascular structures. Note that the blue-whitish veil in this angiokeratoma has no diagnostic significance.

This high magnification of a typical hemangioma depicts the corresponding histopathologic finding of a given red lacuna






Leaf-like areas

The clue for the diagnosis of this basal cell carcinoma is the presence of leaf-like areas (arrows) at the periphery of this lesion. Obviously one needs to have some visual imagination to recognize leaf-like structures!!

Another example of basal cell carcinoma with numerous leaf-like areas (arrows) along the circumference of this lesion. Since no clear-cut pigment network is present, the blue whitish veil has no diagnostic significance.

This superficial type of basal cell carcinoma is composed of large aggregations of basaloid cells some of which contain clusters of melanophages thus forming the so called leaf-like areas






Central White patch

The central white patch represents the dermoscopic hallmark of dermatofibroma, as illustrated in this example

Another example of typical dermatofibroma with a central white patch