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 considered to be a
disease entity separate from low-grade cutaneous angiosarcoma in 1994 [1]. Cutaneous
angiosarcoma has a dismal prognosis, with a high incidence of recurrence and metastasis
and a high mortality rate [1]. Retiform hemangioendothelioma also has a high local
recurrence rate; however, this tumor rarely metastasizes, and no tumor-related deaths
have been reported to date [2,3].
Although retiform hemangioendothelioma occurs across a diverse age range, it is most
common in young or middle-aged adults, with a greater frequency in females [1,3].
It mostly occurs in the limbs, with a higher incidence in the lower limbs [1,3]. But
in the trunk, head, and penis, cases occasionally occur [1,3]. Retiform hemangioendothelioma
mostly occurs as an asymptomatic, slow-growing single lesion [3]. However multiple,
rapid-growing cases have been reported [3,4]. The duration of lesion varies between
2 months to several years [3]. Most cases are presented as exophytic, dermal, or subcutaneous
nodules or plaques with a size range of 1 to 30 cm [3].
The etiology of retiform hemangioendothelioma remains unknown. However several reports
have proposed its association with human herpesvirus-8, lymphedema, previous radiation
treatment, and non-epidermal malignant tumors [1,2].
Local recurrence is observed in almost half of all cases of retiform hemangioendothelioma
[3]. A single case of localized lymph node metastasis and one case of soft tissue
metastasis have been described, but there have been no reports of remote metastasis
or death clearly related to the mass [2,3]. As there is no characteristic clinical
symptom helpful in diagnosing retiform hemangioendothelioma, biopsy is the only diagnostic
method available at present [1,3,5]. The differential diagnosis of retiform hemangioendothelioma
includes Dabska's tumor, malignant lymphoma, dermatofibrosarcoma protuberans, bacillary
angiomatosis, Kaposi's sarcoma, targetoid hemosiderotic hemangioma, and cutaneous
angiosarcoma [1-3]. Histologically, retiform hemangioendothelioma is characterized
by long arborizing vascular channels lined with hobnail endothelial cells. The vascular
channels are arranged in a retiform pattern, which mimics normal rete testis. Prominent
stromal lymphocytic infiltrates are often observed. Immunohistochemically, the endothelial
cells express endothelial markers such as CD31, CD34, factor VIII, and Ulex europaeus
agglutinin-1 [1].
Due to its high incidence of local recurrence, the treatment of choice for retiform
hemangioendothelioma is a wide surgical excision with histopathologically tumor-free
margins and long-term follow-up is essential. In cases with lymph node metastasis,
radiation therapy has been reported to be successful [1]. In addition, in unresectable
retiform hemangioendothelioma was successfully treated with low-dose cisplatin and
moderate radiotherapy in one case [2]. In summary, retiform hemangioendothelioma is
a rare vascular neoplasm of low malignant potential with a high recurrence rate, most
often occurring on the extremities of young adults. To our knowledge, this is the
first case of retiform hemangioendothelioma
reported in Korea.