BACKGROUND: The intraosseous schwannoma (IS) is a benign peripheral nerve sheath tumor postulated to arise de novo or from nerve fibers in preexisting nutrient canals. ISs are uncommon and comprise less than 1% of neoplasms originating in bone. We herein present two cases of mandibular schwannomas-the first case was a 66-year-old female with a four-month history of pain and pressure associated with an anterior mandibular radiolucency, and the second case was an asymptomatic 12-year-old female with separate radiolucencies of her mandibular symphysis and right posterior mandible. Incisional biopsies of all three lesions showed a benign spindle cell neoplasm with histologic features of a schwannoma; the tumor cells were strongly reactive for S-100. The patients underwent complete enucleation of their lesions and are without evidence of disease at ten months and five years, respectively.
METHODS: A systematic review was undertaken to evaluate the diagnostic features, treatment, and patient outcomes of gnathic schwannomas.
RESULTS: A total of 93 cases were identified with the following demographic findings: predominance in females (57%); average age of occurrence of 37.3 years (8 to 77 years); mean size of 3.6 cm; and involvement of the mandibular body (37.6%), mandibular body and ramus (18.3%), and anterior mandible (18.3%). The predominant clinical sign was swelling (69.9%), and the most common radiographic presentation was a radiolucency (94.6%) with well-defined borders (72%).
CONCLUSIONS: All cases were treated surgically, with an average follow-up interval of 22.9 months and a recurrence rate of 5.4.

Ectopic cerebellar tissue has only been described in isolated case reports, with only two reported cases in adult patients. We report the case of a 63-year-old woman with progressive, medically refractory headaches. A scan showed an intraosseous lesion of the midline occipital bone. Surgical resection of the soft tissue lesion was undertaken. Her headaches ceased postoperatively. Histopathological analysis revealed cerebellar cortical tissue with a surrounding meningothelial cell layer, characteristic of cerebellar ectopia. This is the second reported case of an intraosseous location of this lesion, and only the third case described in an adult patient. Our findings illustrate a rare cause of headaches and support the therapeutic roles of surgical treatment for this extremely rare condition.

BACKGROUND: Ectopic cerebellar tissue located distantly from the normal cerebellum is very rare, and its pathophysiology remains to be elucidated.
METHODS: We report an extremely rare case of intraosseous ectopic cerebellum detected incidentally at suboccipital craniotomy in a 46-year-old Japanese woman with hemifacial spasm. She had a small bone defect in the occipital bone, which contained a tiny area of soft tissue surrounded by cerebrospinal fluid connecting to the normal subarachnoid space through a dural opening. Histopathology demonstrated cerebellar cortex tissue consisting of molecular and granular cell layers.
CONCLUSIONS: This is the first report of glioneuronal ectopia within the skull bone separated from normal brain tissue, and it is important to distinguish this entity from other osteolytic lesions.

Giant cell reparative granuloma (GCRG) is benign, non-tumorous granulation tissue. It mainly arises in the jaw bone and occasionally in the hand and foot. Because of the high rate of recurrence, wide surgical resection and autologous bone grafting are recommended. However, this can be problematic for hand function. We present a case report of a 16-year-old boy with a GCRG of the fifth metacarpal bone and the diagnostic difficulties. To treat the patient, we performed a wide resection with the interposition of a corticocancellous bone graft and plate osteosynthesis. 24 months postoperatively the patient shows no signs of recurrence and has good hand function.