Intraosseous epidermoid cyst of the distal phalanx reconstructed with synthetic bone graft.

Intraosseous epidermoid cysts are exceedingly rare. Known as pseudotumors, not true neoplasms, intraosseous epidermoid cysts usually involve the phalanges, the skull, and the toes. Intraosseous epidermoid cysts typically present as destructive osteolytic lesions on X-ray, mimicking malignant bone tumors. Here, we present two cases of an intraosseous epidermoid cyst in the distal phalanx treated with curettage and synthetic bone graft, followed by a review of the relevant literature. In both cases, the patient presented with a painful enlargement of the fingertip following a minor trauma. Magnetic resonance imaging demonstrated lesions involving the distal phalanx that had a low signal on T1-weighted imaging (WI) and a high intensity on T2-WI. In both cases, the lesions were not enhanced by gadolinium. Good remodeling and functional recoveries were obtained. For physically active patients with substantial bone defects, synthetic bone graft may be recommended.

Retro-odontoid mass without atlantoaxial instability causing cervical myelopathy: a case report of transdural surgical resection.

INTRODUCTION: Retro-odontoid mass rarely occur in patients with noninflammatory retro-odontoid lesions without atlantoaxial instability. We describe a rare case of retro-odontoid mass without atlantoaxial instability operated on by a transdural approach. CASE PRESENTATION: The patient was an 83-year-old man who presented with a retro-odontoid mass causing symptomatic cervical myelopathy. Preoperative magnetic resonance imaging (MRI) revealed that the mass was severely compressing the spinal cord. We operated on it via a C1 laminectomy and performed tumor resection by a transdural approach. Pathological findings from the operative specimen confirmed the diagnosis; histopathological examination revealed that the mass contained fibrinoid material, and collagenous tissue with myxoid changes, but no granulation or a granulomatous lesion. Postoperative MRI confirmed spinal cord decompression. The patient's symptoms were alleviated, and he has not had a recurrence or cervical instability in the 7 years since his surgery. DISCUSSION: We successfully used a transdural approach in the present case and have observed no recurrence for 7 years postoperatively. C1 laminectomy is reportedly beneficial, especially for elderly patients, given the risk of other surgical options using an anterior transoral approach or posterior fusion. However, most tumors do not attenuate after C1 laminectomy alone; hence, we think that tumor resection by the transdural approach is one effective method to perform enucleation of the tumor after C1 laminectomy.