Lacunae
Lacunae are multiple well-demarcated round/oval and reddish structures arranged in clusters, separated by a white rim called septae. Histologically, they correspond to dilated, thin-walled vessels in the papillary dermis. Lacunae are the hallmark of vascular tumors, mainly angiomas. Dark (violaceous, blue-black, or black) lacunae reveal partially or completely thrombosed dermal vessels located deeper in the dermis, which are very specific of solitary angiokeratomas [1]. In targetoid hemosiderotic angiokeratomas a central dark lacunae is surrounded by a peripheral red-brownish homogeneous area. Histopathologically, it reveals the presence of less dilated angulated vascular spaces, hemosiderin deposition and extravasated erythrocytes in the mid and deep dermis [2]
