Four Cases of Capillary Aneurysm: Clinical Differential Diagnosis with Malignant Melanoma / 대한피부과학회지

Capillary aneurysm is classically described as a suddenly growing dark papule, and is also known as thrombosed capillary or vein. It is clinically significant that the clinical features of capillary aneurysm are closely similar to those of malignant melanoma or dysplastic nevus. The histopathological finding of capillary aneurysm reveals dilated thin-walled venule(s) just beneath the hyperplastic epidermis, lined by a single layer of endothelium and a thrombus in the lumen. This abstract focuses on four patients who presented with a dark black-colored dome-shaped nodule and clinical impression included malignant melanoma, dysplastic nevus, angiokeratoma and lymphangioma circumscriptum. We herein report four cases histologically diagnosed as capillary aneurysm, which should be considered for differential diagnosis.

A Case of Capillary Aneurysm Simulating Malignant Melanoma / 대한피부과학회지

Capillary aneurysm is classically described as a dark papule and the outstanding clinical feature of this tumor is an appearance simulating a malignant melanoma. In the absence of histopathologic or compelling clinical evidence that the lesion is malignant, the treatment of a black melanoma-like nodule should consist of total but conservative excision. Subsequent biopsy should then indicate whether or not more radical surgery is required. We report a 14-year-old female with capillary aneurysm. She was in good health except for a black colored mottled nodule on her right thigh. Although the clinical resemblance to melanoma was observed, the microscopic view of the biopsy specimen from the center of the lesion revealed that dilated vascular channels lined by a single layer of endothelium, and some of them were surrounded by fibrous tissues in a concentric layer with thrombus. In our case, the nodule was removed with liquid nitrogen.