Retiform Hemangioendothelioma on the Finger

Retiform hemangioendothelioma was differentiated from low-grade cutaneous angiosarcoma by Calonje et al. [1] in 1994; retiform hemangioendothelioma is a very rare tumor of the blood vessels, with less than 30 cases reported throughout the world [2]. The causes of retiform hemangioendothelioma are unknown [2]. Clinically, this tumor occurs mainly in the limbs of young adults, with greater occurrence in the lower limbs, but occasional cases in the trunk, head, and penis [1,3]. Although metastasis or malignancy is rare, retiform hemangioendothelioma is known to recur in approximately 50% of cases [3]. No cases of retiform hemangioendothelioma have previously been reported in Korea. The authors describe the case of a Korean patient diagnosed with retiform hemangioendothelioma. A 20-year-old male patient without any medical history of interest visited the department of plastic and reconstructive surgery of Dankook University Hospital with a mass on the middle phalanx of the left index finger (Fig. 1). The mass began to form about 6 years ago and was gradually enlarged; the patient did not have any history of a wound or a mass in the same region. A soft and compressible protruding mass, with a dimension of 1.5×1×1 cm, was observed. Although there was no open wound, the patient complained of pain when pressed. The finger distal to the mass had normal circulation and sensation. Angiography carried out prior to surgery revealed that the mass corresponded to an angioma (Fig. 2). The patient was administered general anesthesia since the mass was located below the dermis and its boundary was not clear; skin was incised vertically over the mass and 3 mm of normal surrounding soft tissue was excised with the mass. During the excision, the mass did not present any signs of infection or inflammation. Following the excision, the size of the mass was 0.5×0.4 cm, which was considerably smaller than the size prior to excision. Histologically, the lesion was not well demarcated and was composed of elongated and branching blood vessels arranged in a retiform pattern (Fig. 3). The blood vessels were lined with hobnail endothelial cells with focal papillary projections. The endothelial cells revealed enlarged nuclei with vesicular chromatin and rare mitosis. Some lymphocytic infiltrate was observed. Immunohistochemically, the endothelial cells were diffusely positive for factor VIII-related antigen (Fig. 4). The patient was diagnosed with retiform hemangioendothelioma and recovered without complications. However, 2 months after surgery, the tumor had recurred, and the patient was lost to follow-up. Retiform hemangioendothelioma was first considFig. 1. Clinical photograph of retiform hemangioendothelioma on left index finger.