Benign osteoblastoma of the occipital bone: Case report and literature review

We present a case of benign osteoblastoma of the occipital bone. Benign osteoblastoma is an uncommon primary bone tumor, which usually involves the vertebrae and the long bones. This tumor rarely develops in the calvaria, showing a preference for the temporal and frontal bones when it does. To the best of our knowledge, this case is only the eighth reported case of benign osteoblastoma confined to the occipital bone. A 20‐year‐old male presented with a mild tender mass lesion of the occipital area, just below the lambda. Plain X‐ray films and CT scans demonstrated an osteolytic mass surrounded by the sclerotic rim within the diploic space. MRI proved to be effective for the evaluation of the intracranial and intraosseous extensions of the tumor. However, it was very difficult to formulate a differential diagnosis against other osteoblastic tumors, or osteoid osteoma, in view of its radiological appearance. The final diagnosis was obtained by careful consideration of the histopathological characteristics of the tumor combined with its clinical and radiological features. Although generally regarded as benign, a complete resection is preferred over conventional curettage as this can guard against possible recurrence and malignant transformation.     

A huge occipital osteoblastoma accompanied with aneurysmal bone cyst in the posterior cranial fossa

Osteoblastoma is an infrequent benign tumor and skull involvement is extremely rare. The occipital bone is much less frequently involved. We report an unusual case of a huge occipital osteoblastoma with aneurysmal bone cyst in the posterior cranial fossa of a 20-year-old young man. MRI scan and CT three-dimensional reconstruction revealed that the tumor (approximately 8.5 cm x 6 cm x 5 cm) occupied nearly half volume of the posterior cranial fossa. The cerebellum, the forth ventricle and brain stem were compressed remarkably and hydrocephalus was noted. The tumor mass was multiloculated cystic and highly vascular. Excessive bleeding occurred during operation and total removal was achieved. The patient was symptom-free and MRI scan revealed no evidence of recrudescence after a follow-up period of 18 months. Pathological examination revealed that the lesion was a benign osteoblastoma with secondary aneurysmal bone cyst (ABC). ABC constitutes a highly vascular lesion while complete surgical resection is often impeded by excessive intraoperative bleeding. Preoperative embolization may reduce the risk. Despite the benign nature of osteoblastoma, local recurrence after incomplete resection is not rare and malignant transformation during recurrence may occur even after adequate surgery. Our case confirms the findings of previous investigators that if osteoblastoma is removed completely, no recurrence is expected even without adjuvant irradiation and chemotherapy.     

A case of calvarial aneurysmal bone cyst: transcranial contrast sonographic examination with pulse inversion harmonic imaging method]

A 31-year-old female came to our hospital complaining of left frontal bulging with pain on 10 August 2000. The head x-p showed a radiolucent lesion and bulging at the same calvarial site. CT scan and MRI showed fluid-fluid levels, diploic cyst, deformity and hypertrophic calvarial change. There was a partial hypervascular part of cyst adjacent to the left frontal base by selective left external carotid angiography. Harmonic image is a contrast specific imaging modality that uses the nonlinear properties of contrast agents by transmitting at the fundamental frequency and receiving at multiples of these frequencies. Pulse inversion harmonic image(PIHI) using pulse inversion to eliminate and strengthen the harmonic frequency is more effective than conventional harmonic imaging. Transcranial sonographic examination showed hyper- and hypoechoic appearances in the cyst around abnormal hyperechoic appearances of the calvarial site. The transcranial contrast sonographic images with PIHI (hereinafter TCIpi) demonstrated an enhanced intracystic lower stratum and nearby the diploic part. That modality facilitates better visualization than the harmonic imaging method, enabling differentiation of vascular from avascular areas. As contrast agents are microbubbles, those are restricted in the vascular canal space. So TCIpi findings proved to be a blood circulation of the tumor, cyst and neighboring tissue. Enhanced areas changed by every minute and disappeared gradually. The findings were probably based on the vascular component of the tumor. We obtained images similar to those with CT and MRI. The patient underwent on 21 August. The tumor was removed along with the surrounding skull component. Fresh and old blood were mixed in the cyst. The clinical and pathological diagnosis was aneurysmal bone cyst. The postoperative course was uneventful and she was discharged on 29 August. Aneurysmal bone cyst is a rare calvarial tumor. An diagnostic finding is fluid-fluid levels that appear in approximately 30% of aneurysmal bone cysts. However, this is not a specific finding and has also been reported to occur in osteosarcoma, malignant fibrous histiocytoma, fibrous dysplasia, synovial sarcoma, hemangioma and simple bone cyst. Therefore, diagnosis of aneurysmal bone cyst is based on a combination of the various imaging applications, clinical and pathological findings. Gometz reported that sonographic examination was superior to any diagnostic imaging studies for aneurysmal bone cyst. Furthermore, the perfusion examination like TCIpi can directly observe blood circulation channels in tissue, so the specific enhancement changes of aneurysmal bone cyst could be observed. TCIpi is a useful method for diagnosis of aneurysmal bone cyst.     

Unusual primary intracranial dural‐based poorly differentiated synovial sarcoma with t(X; 18)(p11; q11)

Synovial sarcoma is a rare aggressive neoplasm occurring at any site of the body, mainly in young adults. It may also arise in the CNS but has seldom been reported. We report a case of unusual intracranial synovial sarcoma in a young male patient. Neuroimaging revealed a large gadolinium‐enhancing mass was located at the right anterior cranial fossa and was associated with multiple cyst formation. The mass was dural‐based and was observed to invade the right orbital apex and ethmoidal bulla. Histologically, the tumor was composed of uniform oval and round cells with scant cytoplasm and indistinct borders. The tumor cells were observed to form densely cellular sheets, but in some areas, the tumor showed hemangiopericytomatous vascular pattern consisting of tumor cells arranged around dilated, thin‐walled blood vessels. By immunohistochemistry, vimentin, CD99 and Bcl‐2 were diffusely positive in most cells, and a focally weak reactivity for S‐100 protein was also observed. However, the tumor cells were negative for cytokeratin (AE1/AE3), CK7, CK8/18, CK19, epithelial membrane antigen, CD34, synaptophysin, GFAP, desmin, myogenin, and smooth muscle actin. Cytogenetic analysis using fluorescence in situ hybridization (FISH) demonstrated a translocation t(X;18)(p11;q11), an aberration specific for synovial sarcoma. A diagnosis of primary dural‐based poorly differentiated synovial sarcoma was made. To our knowledge, this is the first report of a poorly differentiated variant of synovial sarcoma occurring in dura mater and confirmed by cytogenetic analysis. The present case indicates that appropriate immunohistochemical analysis, and in particular molecular analysis, are essential for accurately diagnosing small, round‐cell neoplasms in unusual locations.     

Primary ALK‐1‐negative anaplastic large cell lymphoma of the brain: Case report and review of the literature

Anaplastic large cell lymphoma (ALCL) is a type of non‐Hodgkin lymphoma composed of CD30‐positive cells. Anaplastic lymphoma kinase (ALK) ‐1 positive ALCL frequently involves both lymph nodes and extranodal sites. While primary extranodal involvement of ALK‐1 negative ALCL is rare, this case is unique in that it is a case of primary ALK‐1 negative ALCL of the brain. A 79‐year‐old man presented with dementia‐like symptoms. Neuroimaging revealed a well‐enhanced mass in the left parieto‐occipital region. The tumor was excised and histological diagnosis of primary ALK‐1‐negative ALCL was made. Primary ALK‐1‐negative ALCL in this case showed aggressive clinical behavior and fatal outcome. It is of great importance to avoid any delay in reaching an accurate diagnosis, as even primary ALCL of the brain is too seldom suspected clinically.     

Fibrous Dysplasia with Aneurysmal Bone Cyst Presenting as Painful Solitary Skull lesion

We report a rare case of fibrous dysplasia with the development of a secondary aneurysmal bone cyst presenting as solitary tumor of calvarium. Although fibrous dysplasia with aneurysmal bone cyst is rare, it should be taken into account in differential diagnosis of the osteolytic solitary skull lesion.     

Aneurysmal bone cyst of the sphenoid sinus

Aneurysmal bone cyst is an uncommon lesion that occurs mainly in long bones and vertebrae, being the location in the sphenoid sinus extremely rare. Its origin is unknown, but it can be considered as a vascular phenomenon secondary to a primary lesion. Other primary diseases that may be associated to aneurysmal bone cyst are polyostotic fibrous dysplasia and giant-cell tumors. We report the case of a patient with an aneurysmal bone cyst in the sphenoid sinus causing vision dysfunction.     

Benign Osteoblastoma Located in the Parietal Bone

Benign osteoblastoma is an uncommon primary bone tumor, extremely rare in calvarium. We present a case of a 25-year-old female with an osteoblastoma of parietal bone which was totally resected. The authors discussed the clinical presentation, radiographic finding, differential diagnosis and management of the benign calvarial osteoblastoma with a review of the literature.     

椎管内肠源性囊肿诊治体会(附12例报告)

目的探讨椎管内肠源性和气管源性囊肿的诊断及显微外科治疗的效果。方法回顾性分析经手术及病理证实的10例椎管内肠源性和2例气管源性囊肿患者的临床资料。结果该12例椎管内囊肿均常规行脊柱X线及MRI检查,术前无1例确诊,术中仅1例高度怀疑,术后病理证实肠源性囊肿Ⅰ型7例、Ⅱ型3例,支气管源性囊肿Ⅱ型2例;12例中6例全切,4例大部分切除,2例行囊壁部分切除+囊腔-蛛网膜下腔沟通术。结论①椎管内肠源性囊肿术前诊断较困难,脊柱MRI是其首选辅助检查,确诊有赖于病理诊断;②对于椎管内囊性病变术前均应考虑肠源性囊肿的可能,术中应留取标本进行组织病理学检查;③椎管内肠源性和气管源性囊肿手术应在保留脊髓功能的前提下尽可能全切囊壁,大多数患者预后良好。     

Chordoma coexisting with Rathke's cleft cyst: Case report and literature review

Both chordoma and Rathke's cleft cyst are relatively rare diseases in the central nervous system. In this paper we report the first case of a chordoma coexisting with a Rathke's cleft cyst. A 49‐year‐old man presented with a 19‐month history of distending pain, movement dysfunction and diplopia of the left eye. The preoperative diagnosis was consistent with chordoma with cystic change. Final pathological diagnosis of chordoma coexisting with Rathke's cleft cyst was made according to histological and immunohistochemical studies and the clinical and radiological features are discussed. Considering the close relationship between the notochordal tissue and Rathke's pouch during early embryogenic development, a possible mechanism is also discussed with the literature review.     

Osteoma osteoide raquídeo recidivante en forma de osteoblastoma agresivo

We report an uncommon case of osteoid osteoma recurring as an aggressive osteoblastoma of the spine. A 15-years-old male consulted in our department with long-term painful scoliosis. The CT-scans and MRI revealed a sclerotic bone forming tumor of 7 mm diameter consistent with a osteoid osteoma. A percutaneous radiofrequency ablation was performed with complete resolution of the symptoms. After 6 months, the symptoms recurred. A new CT and a MRI showed a growth of the nidus on the right L4 lamina, with a size of 15 mm. Therefore, a marginal resection by laminectomy of L4 was performed. Pathology confirmed an epithelioid osteoblastoma.A year later, subsequent imaging studies showed a new recurrence with aggressive features and invasion of the spinal canal. The patient then underwent an “in block surgery” needing concurrent stabilization of the spine. Histopathology confirmed the diagnosis of epithelioid osteblastoma.     

Metástasis sacra simulando quiste óseo aneurismático

Cystic spinal lesions with characteristic patterns, such as the presence of haematic fluid-fluid levels (H-FFL), have been associated with many tumoral lineages, more frequently with aneurysmal bone cyst (ABC) and exceptionally with metastasis. We present the case of a 60-year-old man with the finding of a sacral cystic bone lesion with H-FFL, with initial suspicion of ABC and confirmed diagnosis of metastasis. The case presented is, to our knowledge, the second case published of spinal cystic bone metastasis with H-FFL pattern with unknown primary tumour at the time of diagnosis and the only one that received resective surgical treatment, achieving pulmonary and metastatic disease control with good quality of life after 1 year of follow up.     

Chondromyxoid fibroma of the seventh cervical vertebra

Chondromyxoid fibroma is a rare benign bone tumor representing less than 0.5% of all bone tumors. It commonly involves the long tubular bones. Involvement of the spine is rare. A 35-year-old man presented with history of neck pain, restriction of neck movements, pain and numbness along the medial aspect of the left forearm and weakness with wasting of the left hand. A presumptive diagnosis of a bony tumor such as an aneurysmal bone cyst or a giant cell tumor involving the seventh vertebral body was made on plain X-rays, MRI and bone scan. He underwent C7 central corpectomy, incomplete intralesional curettage with iliac bone grafting and C6 to T1 interspinous wiring. The histological diagnosis was chondromyxoid fibroma. On eight years' follow-up, CT scan showed no progression of the tumor with good alignment and fusion of the graft at the site of the corpectomy. The authors conclude that corpectomy and iliac bone grafting for chondromyxoid fibroma has a good outcome on long-term follow-up.     

Dura mater graft‐associated Creutzfeldt‐Jakob disease with 30‐year incubation period

Over 60% of all patients with dura mater graft‐associated Creutzfeldt‐Jakob disease (dCJD) have been diagnosed in Japan. The incubation period has ranged from 1 to 30 years and the age at onset from 15 to 80 years. Here, we report a 77‐year‐old male Japanese autopsied dCJD case with the longest incubation period so far in Japan. He received a cadaveric dural graft at the right cranial convexity following a craniotomy for meningioma at the age of 46. At 30 years post‐dural graft placement, disorientation was observed as an initial symptom of dCJD. He rapidly began to present with inconsistent speech, cognitive impairment and tremor of the left upper extremity. Occasional myoclonic jerks were predominantly observed on the left side. Brain MRI presented hyperintense signals on diffusion‐weighted and T2‐weighted images, at the right cerebral cortex. The most hyperintense lesion was located at the right parietal lobe, where the dura mater graft had been transplanted. Single‐photon emission CT scan showed markedly decreased cerebral blood flow at the right parietal lobe. EEG revealed diffuse and slow activities with periodic sharp‐wave complex discharges seen in the right parietal, temporal and occipital lobes. He died of pneumonia 9 months after onset. Brain pathology revealed non‐plaque‐type dCJD. Laterality of neuropathological changes, including spongiform change, neuronal loss, gliosis or PrP deposits, was not evident. Western blot analysis showed type 1 PrP^CJD. Alzheimer‐type pathology and PSP‐like pathology were also observed.     

Aneurysmal bone cyst concomitant with fibrous dysplasia in the frontal bone

Secondary aneurysmal bone cyst in fibrous dysplasia is exceedingly rare, especially in the skull and particularly in the frontal bone. We present a case of aneurysmal bone cyst concomitant with fibrous dysplasia in the frontal bone in a 15-year-old male patient presenting with headache and euphoria with an uncharacteristic imaging appearance and treated successfully by total resection.     

Endodermal cyst of the cervical spinal cord with associated partial fusion of the vertebrae

A case of a 43‐year‐old woman with an intradural endodermal cyst at the C4 spinal cord level is presented. The lesion manifested with progressive neck pain and weakness of lower extremities. The presumptive diagnosis of extramedullary benign cystic lesion was established after MRI examination. Coexisting partial fusion of the C5‐C6 vertebral bodies was found on X‐ray films. The patient was cured by resection of the cyst wall, performed by laminectomy. Pathological examination revealed a cyst wall lined with ciliated cuboidal cells, resembling the respiratory epithelium. Immunohistochemistry demonstrated cytokeratin and epithelial membrane antigen expression in the lining of the cyst. Endodermal cyst should be considered in the differential diagnosis of intraspinal cystic lesions, especially those associated with vertebral anomalies.     

Primary frontal‐lobe germinoma appearing as a large cyst

In the present case, a primary frontal‐lobe germinoma in a 20‐year‐old man is reported. This is the first such case to be investigated by autopsy. The tumor appeared on a CT scan as a large cystic lesion in the frontal‐lobe white matter. At autopsy, the typical two‐cell histology pattern was seen mainly in the area of the cyst wall. Although cyst formation is a frequent feature of germinomas, the presence of a large cystic lesion in the cerebral white matter, as demonstrated in the present case, is very rare. The present case provides further radiographic data that might be useful for the future diagnosis of this tumor, which is radiosensitive and potentially curable.     

Hickam's dictum: Angiosarcoma‐to‐meningioma metastasis

Tumor‐to‐tumor metastasis is a seldom reported phenomenon whereby a neoplasm seeds within another histologically distinct tumor, with only 84 cases documented in the literature. We hereby describe the case of a 95‐year‐old woman who died of widespread metastases identified as a primary hepatic angiosarcoma on autopsy, and the interesting finding of a seeding foci within a dural meningioma. Although meningiomas are the most common intracranial neoplasms to harbor such a phenomenon, this is to our knowledge the first case where an angiosarcoma was identified as the donor tumor.     

Meningeal alveolar soft part sarcoma confirmed by characteristic ASPCR1‐TFE3 fusion

Sarcoma metastatic to the brain is uncommon and rarely occurs as the initial manifestation of tumor. Alveolar soft part sarcoma (ASPS) is a rare but well‐studied subtype of sarcoma. A 39‐year‐old man presented with seizures due to a left temporal meningeal‐enhancing lesion with striking brain edema on MRI. The patient underwent neurosurgical resection for suspected meningioma. Histology showed large tumor cells clustering and forming small nests, in places with pseudoalveolar pattern. Diastase‐resistant periodic acid‐Schiff revealed very rare granular and rod‐like cytoplasmic inclusions. Immunohistochemistry showed convincing positivity only with vimentin and smooth muscle actin. The histological features were strongly suggestive of ASPS. At the molecular level RT‐PCR and sequencing analysis demonstrated ASPCR1‐TFE3 fusion confirming the histological diagnosis of ASPS. There was no evidence of primary extracranial tumor by physical examination and on chest and abdominal CT scan 11 months after presentation. ASPS typically arise from the soft tissues of the extremities and develop multiple metastatic deposits usually with a long clinical course. This case may represent primary meningeal ASPS although metastatic deposit from an undiscovered primary site cannot be entirely excluded.     

Low‐grade follicular lymphoma in the dura: Rare mimic of meningioma

Lymphomas rarely present as a localized mass within the dura. We report a case of a 72‐year‐old woman, normally fit and well, who presented with a sudden episode of grand mal seizure. Imaging studies showed an extra‐axial mass arising from the dura, with radiologic features characteristic of a meningioma. The mass was surgically excised, and the histologic features were of a grade 1 follicular lymphoma. Analysis using fluorescent in situ hybridization (FISH) demonstrated t(14:18) translocation. A bone marrow aspirate showed focal infiltration of lumbar vertebra by low‐grade follicular lymphoma. Intracranial meningeal involvement by non‐Hodgkin lymphoma usually occurs in the form of diffuse leptomeningeal spread. It is seen in high‐grade lymphomas, often in association with widespread systemic disease. The majority of cases of dural lymphomas reported in the literature have been primary mucosa‐associated lymphoid tissue (MALT)‐type lymphomas. Most of these presented as localized dural masses mimicking meningiomas. Low‐grade follicular lymphoma, either primary or secondarily involving the dura, appears to be an exceedingly rare occurrence.