Solid Variant of Aneurysmal Bone Cyst of the Cervical Spine

Abstract

The solid variant of aneurysmal bone cyst should be included in the differential diagnosis of any lytic expansile lesion of the spine, even though it is a destructive lesion. Gd-enhanced magnetic resonance imaging may be helpful for distinguishing the solid variant from conventional aneurysmal bone cyst.

Solid variant of aneurysmal bone cyst on the cervical spine of a child: case report, differential diagnosis and treatment rationale

“…However, there is another distinct variant of ABC, the so-called solid variant, that was first described by Sanerkin et al [5] in 1983. It is a rare lesion, accounting for 3.4-7.5 % of all ABCs, and only 15 cases (including our patient) occurring in the spine have been reported [6,7]. Pediatric age group patients have been almost exclusively involved, ranging in age from 6 to 17 years (mean age 10.8 years) and the male:female ratio was 1:1.9.…”

“…This is similar to conventional ABC. However, conventional ABC's septation seen in Gd-enhanced, T1-weighted images or T2-weighted images have never been reported in the solid variant [7]. Suzuki et al [7] described homogenous high signal intensity throughout the lesion on Gd-enhanced MRI images, whereas in conventional ABC only the periphery of the lesion has that kind of signal.…”

“…On histological examination, a solid cystic variant is characterized by fibroblastic proliferation and absence of bloodfilled spaces [1,7]. The term S-ABC proposed by Sanerkin et al [5] is histologically characterized by the following features: (1) florid fibroblastic or fibrohistiocytic proliferation without any cellular or nuclear pleomorphism, (2) areas rich in osteoclast-like giant cells, (3) osteoblastic differentiation with osteoid production, (4) aneurysmal sinusoids, and (5) occasional foci of degenerate calcifying fibromyxoid tissue.…”

“…Pain (neck, back or chest) was the most common initial clinical symptom. Swelling, palpable tender mass, radiculopathy, myelopathy and scoliosis were less commonly reported signs/symptoms [7]. On average, symptoms persist for 12 months before definitive diagnosis [6].…”

“…In all of these three cases the posterior elements were also affected. In terms of imaging, routine radiographic features on plain radiographs [6,7] and CT scans [6] of the S-ABC include an osteolytic and expansile lesion that is indistinguishable from conventional ABC. Bone scintigraphy may reveal ring-like accumulation [8]-''donut sign'' [9]-at the edge of the lesion.…”