Schwannoma of the fibula

Abstract

We describe a schwannoma located in the mid-diaphyseal region of the fibula of a 14-year-old boy. Radiologically this was an expansile, lytic, globular and trabeculated lesion. MRI showed a narrow transition zone with a break in the cortex and adjacent tissue oedema. Differential diagnosis included schwannoma, fibrous dysplasia, giant cell tumour and aneurysmal bone cyst. The tumour was excised en bloc, with marginal resection limits, and there has been no recurrence two years after surgery. Histopathological examination confirmed the diagnosis of classic schwannoma. There were typical hypercellular Antoni A zones, less cellular Antoni B zones, and diffuse immunoreactivity to S100 protein. This is the first report of schwannoma involving a long bone in a child.

Association between intraosseous schwannoma occurrence and the position of the intraosseous nutrient vessel: A case report

“…Therefore, an intraosseous schwannoma involving a long bone may be associated with the second mechanism, the tumor arises and develops within the nutrient canal, and related to the site of the nutrient artery; however, the most common location of intraosseous schwannomas in long bones remains to be elucidated. A total of 4 cases of intraosseous schwannoma of the fibula were previously reported with clear radiographic figures (4)(5)(6), and 3 of these cases occurred in the diaphysis of the fibula. As free vascularized fibular grafts have been widely used to cover skeletal bone defects larger than 6 cm (16), it has been reported that the nutrient canal into the fibula is positioned between 12 and 18 cm from the tip of the fibula, in the diaphysis (17).…”

“…Fewer than 200 cases have been previously reported; of these cases, the most common sites of the involved bones were the mandible and sacrum (2). Although a number of cases of intraosseous schwannoma involving the long bones have been previously reported (3)(4)(5)(6)(7)(8), this type of disease is relatively rare, and the typical location at which an intraosseous schwannoma of the long bones may arise is uncertain. Intraosseous schwannoma presents as a slowly enlarging and painless mass (8); however, if the bone becomes affected and a microfracture is caused, the mass becomes painful.…”

“…Although it has been reported that pathological fractures are rare in intraosseous schwannoma (4), pathological fractures may occur in slender bones, including the ulna (6). Radiographically, it may be difficult to distinguish intraosseous schwannomas from other benign bone tumors, including solitary bone cyst, aneurysmal bone cyst, giant cell tumor, benign chondroblastoma or fibrous dysplasia (4).…”

“…On magnetic resonance imaging (MRI), soft tissue schwannomas typically appear isointense to muscle on T1-weighted images and homogeneously or heterogeneously hyperintense to fat on T2-weighted images (9), but not specifically. The tumors may only be diagnosed by microscopic findings, which is difficult without biopsy or surgery (1,6).…”

Intraosseous schwannoma originating from the posterior column of the thoracic spine

“…Intraosseous schwannomas (neurilemmomas) are rare benign neoplasms that account for \0.2% of primary bone tumors [5,11]. Except for the long bones, the most common site of involvement is the mandible, and only eight cases involving the mobile spine have been described in the English literature [1-4, 8-10, 12].…”