This case is rare in comparison with majority of reported SCH cases and merits discussion on following points: location of lesion, selection of surgical intervention, histopathologic characteristics, and long-term postoperative follow-up. SCH is a benign vascular lesion which generally locates in the subcutis at the distal extremities and presents as solitary and multifocal masses. It also can be associated with several clinical syndromes, among which Maffucci syndrome is the most common[8, 9]. In several uncommon cases, SCHs have been found in lips, nasal passage, temporal muscle, and even in lungs and spleen[2, 10–13]. In comparison, the reported cases of SCH arising in bones are even more unusual so far[14–16]. In our case, a solitary lesion of SCH involved the proximal fibula with surrounding soft tissue hyperplasia, while the superficial skin and tissues were normal.
To date, the main treatment choice for fibular tumor is segmental or subperiosteal resection, in case of local recurrence at surgical site[17–19]. Given that preoperative digital radiograph indicated that the vascular mass on fibula was solitary, and part of both cortex and cancellous fibula were not involved, intralesional curettage was selected as the surgical intervention in this case for achieving the maximum retention of healthy bony structure. During the operation, complete curettage was performed to the normal fibular surface without residual lesion.
The histologic appearance in this case consisted of the fissure-like vessel lumens lined with flattened endothelial cells among the spindle cells, which arranged in fascicular pattern in solid area. Subsequent immunohistochemical analysis revealed positive staining for CD31, CD34 and ERG in the majority of spindle cells, consistent with the diagnosis of SCH[20, 21]. Metastasis of SCH is rare, although local recurrence may occur[22, 23]. On the most recent imaging examination, 2 years after the initial surgery, our patient was still disease-free and found to experience entire reformation of bone structure of right proximal fibula. This indicates the safety and effectiveness of intralesional curettage for the management of this case.