Besides EHE, the goup of hemangioendotheliomas includes the kaposiform Dabska tumor (papillary intralymphatic angioendothelioma), spindle-cell, retiform (hobnail hemangioendothelioma), and composite [3
EHE is a rare neoplasm of the vascular endothelium, which was described for the first time in 1982 by Weiss and Enzinger as a subgroup of the hemangioendotheliomas having an important endothelial or histiocytic component [6
]. Weiss and Enzinger, publishing their 46-patient series, reported for EHE a recurrence rate of 13% and a development rate of 31% for local-regional lymph metastases in the course of a 48-month follow-up period. On the same series the mortality rate was 13% [3
]. The subsequent published series were smaller, so that the EHE mortality rate ranged between 0 and 20% in the case of monitorization periods between 3.5 and 4.4 years [3
]. These initial studies were followed by case reports regarding other localizations, such as hepatic, pulmonary [10
], and bone. In 55% cases EHE is multicentric and in 40% cases several bones are involved [3
Clinically, EHE is accompanied by pain and swelling. On radiological examination, EHE is an expansive, osteolytic and poorly demarcated lesion. EHE occurs in male\ adults during the second or third decade of life, 60-80% involving the femur, tibia, fibula, or metatarsals [9
]. Multiple lesions may be present at the level of one single bone. Also, in the bone, EHE is found in the metaphysis or epiphysis. Pathological fractures may also occur [1
The preoperative evaluation of the EHE must be as complete as possible. The clinical examination should be completed with extensive imagistic investigations. Ultrasonography emphasizes its vascularization and allows a differential diagnosis vis-à-vis an arteriovenous malformation or even an aneurysm. Taking into consideration the rarity of the malignant character of bone EHE, especially at the upper limb level, the soft tissue sarcoma is the closest diagnosis that would come into discussion. The radiology examination and the MRI are necessary in order to determine the degree of the neoformation, the relations with the surrounding tissues, the possible existence of a cleavage plan, and the morphological data about the lesion [2
The definite EHE diagnosis is established after a careful histopathological extensive differential diagnosis with Langerhans cell histiocytosis, angiosarcoma, infection, myeloma, metastasis, and lymphoma, intranodal palisaded myofibroblastoma, and other tumors of the hand and forearm region [12
]. Since malignancy is only rarely presumed preoperatively, full body CT scans and/or positron emission tomography survey to detect the presence of local-regional or distant metastasis are conducted just as seldom [2
Because the cytology prior to the surgical treatment cannot always confirm the malignant character, the treatment of choice is the complete local excision of the tumor with or without regional lymphadenectomy [2
]. The amputation of the extremity of the limb is necessary only in the cases where the tumor has a high degree of infiltration. This attitude, namely the amputation above the elbow, was adopted in the case reported by Lai et al. [15
] of a Kasabach-Merritt syndrome, characterized by a malignant hemangioendothelioma to which thrombocytopenia, hemolytic anemia, and consumption coagulopathy have been associated. The case reported by Duncan et al. [3
] as an expandable tumor of the distal third of the pathologically fractured radius and which, after resection, required a radius reconstruction, is a conclusive example of bone EHE, the second after Tsuneyoshi [8
], among which, out of a series of 14 reported patients with EHE, only in the case of 1 patient was the radius involved.
The particularity of our case consists in the surgical solution that did not require radius reconstruction or even upper limb amputation, similar to the other two cases. The subsequent favorable evolution in time of our case is an argument in favor of the correctness of the selected complex diagnostic and therapeutical attitude, the latter of which combined surgery and radiotherapy. To the best of our knowledge, we are describing the third case of EHE with distal radius involvement.
A standardized therapeutic approach is difficult to adopt due to the extremely low incidence of bone involvement or primitive bone EHE (under 1% of the total number of vascular tumors) and also because of the variable tendencies thereof towards malignancy [16
The role of radiotherapy remains controversial, because of the same reason very few series of reported patients. In the series of Kleer et al. [8
] 4 out of 10 patients who underwent radiotherapy for EHE had a favorable evolution, and Rosenthal et al. [17
] mentioned the efficaciousness of radiotherapy in a case of a patient with multifocal bone EHE. The role of adjuvant chemotherapy, on the other hand, in the treatment of EHE, has not been established so far [8
In summary, bone EHE, the destructive local level tumor with a variable evolution, is remarkable because of the diagnostic difficulties, both from a clinical and a histopathological point of view, resulting in a high frequency of initial misdiagnosis. Its behavior cannot be predicted based only on the histological characteristics, the most important criteria in the appreciation of an unfavorable prognosis seems to be the visceral implication [8
]. Under these circumstances, and taking into consideration the particular situation of the reported case, in our opinion, EHE should be investigated via skeletal screening. When the osteolytic lesions involve more than 50% of the cortex there is a serious risk for pathological fractures [11
]. Our case is in accordance with the previous reports as far as the treatment conduct is concerned, consisting in complete large excision followed by radiotherapy and subsequent monitoring.