Plexiform neurofibroma causing an ossifying subperiosteal haematoma: a rare case in the tibia of an 11-year-old girl

Abstract

Ossifying subperiosteal haematoma is an exceedingly rare manifestation of Neurofibromatosis type 1 (NF-1). We report an interesting case of plexiform neurofibroma causing a rapidly growing tibial mass as a result of subperiosteal haemorrhage, in an 11-year-old girl with previously undiagnosed NF-1. This reflects a precursor of the more mature periosteal ossification seen in cases traditionally termed "subperiosteal cysts". A previously well young girl was referred by her general practitioner with an increasingly large, mildly tender, soft lump on the anterior aspect of her right tibia. Plain radiographs demonstrated soft tissue thickening overlying the anterior tibia, without appreciable periosteal ossification. Magnetic resonance imaging (MRI) illustrated a single central fluid-fluid level and periosteal elevation with saucerisation of the anterior tibial cortex and mild surrounding oedema. Histopathology revealed a large plexiform neurofibroma. Interestingly, this was associated with haemorrhagic change and a peripheral rim of florid reactive new bone formation. This unusual presentation was discussed at a multidisciplinary bone and soft tissue tumour meeting, where in combination with the clinical history of café au lait spots and positive family history, a consensus diagnosis of NF-1 was made. To date, there have only been limited case reports of this rare pathological process. In summary, this case report accounts an acute presentation of this rare osseous manifestation of NF-1, being the first to clearly demonstrate a timeline of subperiosteal haematoma with subsequent subperiosteal bone proliferation. The clinical reasoning and radiological features for such a presentation are also described.

Subperiosteal hemorrhage: A rare complication in neurofibromatosis which may mimic malignant peripheral nerve sheath tumor

“…Affecting 2-3/10,000 population, neurofibromatosis is the most common phakomatosis [4]. There are rare case reports of spontaneous subperiosteal hemorrhage in NF-1 patients with 2 reports demonstrating the subperiosteal neurofibromas with concomitant hemorrhage, this case being the third [3], [4], [5], [6], [7], [8], [9], [10].…”

“…The pathogenesis of subperiosteal hemorrhage is thought to be from 2 factors, vascular fragility and weakened periosteal attachment secondary to mesodermal dysplasia and/or periosteal involvement by a plexiform neurofibroma [8]. With little or no trauma, large and recurrent subperiosteal hemorrhages can occur [3].…”

“…With little or no trauma, large and recurrent subperiosteal hemorrhages can occur [3]. At the same time, the periosteal and subperiosteal spaces can be involved with neurofibromas thought to arise from periosteal nerves [5], [8]. When small, these can be occult on imaging.…”

“…Levell et al provided a very detailed history of the findings of subperiosteal hematoma with a review of literature to date on reported cases [8]. The authors also propose an evolution of imaging findings in patients with NF and subperiosteal hematoma.…”

Case Report: Ossified Subperiosteal Hematoma in the Humerus of a Lacrosse Player

“…Ossified subperiosteal hematomas represent a hemorrhagic collection between the cortex and periosteum of bone. Ossified subperiosteal hematomas have been described in the calvarium [1][2][3][4], tibia [5][6][7][8], femur [5,9,10], and iliac bone [11][12][13]. Martinez-Lage and colleagues described a case of a 5-month-old boy who presented with sagittal synostosis due to a ossified cephalohematoma of the cranial vault who underwent bilateral parasagittal craniectomies and removal of the ossified hematoma en bloc [4].…”