Giant intradiploic epidermoid cyst of the occipital bone

Epidermoid cysts are uncommon, benign and slow-growing lesions. They often reach an enormous size without producing neurologic symptoms. We describe a 35-year-old female who had a giant intradiploic epidermoid cyst of the occipital bone. She underwent posterior cranial fossa tumor resection. Pathology confirmed epidermoid cyst. There was no recurrence at 13-month follow-up. Total removal of these cysts and repeated washing of the cavity with 0.9% saline may prevent recurrence and aseptic meningitis.     

Aneurysmal bone cyst of the orbit : a case report with literature review

Aneurysmal bone cyst (ABC) is benign vascular lesion destructing the cortical bone by the expansion of the vascular channel in the diploic space that usually involve long bone and spine. Orbital ABC is rare and the clinical symptoms deteriorate rapidly after initial slow-progression period for a few months. A 12-year-old female patient visited ophthalmologist due to proptosis and upward gaze limitation of the right eye, and orbital mass was noted in the upper part of right eye on orbital MRI. Five months later, exophthalmos was worsened rapidly with other features of ophthalmoplegia. Orbital mass was enlarged on MRI with intracranial extension. Surgery was done through frontal craniotomy and intracranial portion of the tumor was removed. Destructed orbital roof and mass in the orbit was also removed, and surrounding bone which was suspected to have lesion was resected as much as possible. Histopathological diagnosis was aneurysmal bone cyst. Postoperative course was satisfactory and the patient's eye symptoms improved. Authors report a rare case of orbital ABC with review of the literature. Exact diagnosis by imaging studies is important and it is recommended to perform surgical resection before rapid-progressing period and to resect the mass completely to prevent recurrence.     

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.     

前颅底动脉瘤样骨囊肿1例并文献复习

目的探讨颅内动脉瘤样骨囊肿的临床特点、影像学特征及治疗方法;提高对颅内动脉瘤样骨囊肿的认识。方法回顾分析中国医科大学附属盛京医院1例经手术、病理检查证实的,前颅底动脉瘤样骨囊肿患儿的临床资料;并对相关文献进行复习。结果患儿行显微镜下手术全切除病变,术中见肿瘤位于硬膜外,广泛分布于颅底,向眶内生长,颅底骨质变性增厚。分块切除肿瘤组织,见肿瘤质韧,色粉红,大小约5 cm×4 cm×3 cm。术后病理检查为动脉瘤样骨囊肿。术后患儿恢复良好,随访1年未见复发。结论颅内动脉瘤样骨囊肿临床非常罕见,病因尚不明确;临床表现与其大小和部位有关,影像学检查有特征性表现,显微镜下手术完整切除病变可获得良好预后。     

Giant pediatric aneurysmal bone cysts of the occipital bone: case report and review of the literature

Cranial aneurysmal bone cysts are uncommon. Cranial aneurysmal bone cysts of the occipital bone are exceedingly rare. A 2-year-old toddler with this rare cyst presented with a large space-occupying lesion of the posterior fossa, with cerebellar tonsillar herniation. The patient experienced complete recovery after total excision of the lesion. We review the literature regarding this rare presentation, and discuss the origin, pathogenesis, pathologic features, imaging characteristics, and treatment of cranial aneurysmal bone cysts.     

Intraspinal dural‐based primary osteoblastoma with aneurysmal bone cyst‐like change

Osteoblastoma is a benign bone‐forming neoplasm that occurs commonly in the posterior elements of the spine and the sacrum. However, so far there has been no report of intradural osteoblastoma described in the literature. We present a unique case of intraspinal dural‐based osteoblastoma with aneurysmal bone cyst‐like change without evidence of vertebral involvement. An 11‐year‐old Chinese girl presented with a 3‐month history of gradually progressive back pain and a weakness of both lower limbs. Thoracic MRI revealed a well‐demarcated subdural mass at the T5 level with heterogeneous enhancement. Histologically, the tumor was found to be attached to the dura and composed of numerous osteoid spicules and trabecular bone with diffusely scattered osteoclast‐type, multinucleated giant cells. Ectactic blood vessels and blood‐filled cystic spaces were also observed. A diagnosis of primary intraspinal dural‐based osteoblastoma with aneurysmal bone cyst‐like change was made. To our best knowledge, this is possibly the first case of primary osteoblastoma arising from meninges. Meningeal osteocartilaginous tumors are rare, with obscure histogenesis. The differential diagnosis of osteoblastoma in unusual locations is difficult and the confirmation of diagnosis should be cautiously made. Awareness of dural‐based osteoblastoma and its histological features is important to avoid a diagnostic pitfall caused by histological similarities to other intra‐craniospinal lesions with osteoid differentiation or bone formation.     

Giant intradiploic epidermoid cyst of the occipital bone

A rare case of giant intradiploic epidermoid cyst of the occipital bone with large intracranial extension in the posterior fossa is described. The lesion was discovered when the patient presented with headache and subcutaneous swelling in the occipital region, in the absence of signs of neurological involvement. CT scan showed extensive destruction of the occipital bone, mainly of the inner table, up to the foramen magnum. On MRI the lesion was hypointense in T(1) and hyperintense in T(2)-weighted images; signal inhomogeneity was due to cellular debris and cholesterol crystals. The enhancing rim due to the thickened dura confirmed the extradural location. Complete removal of the cyst was easily accomplished despite its large size. We found only 3 documented cases in the literature of giant intradiploic infratentorial epidermoid cysts, none of which was studied by MRI. The radiological features and differential diagnosis are discussed.     

Cystic Giant Sacral Schwannoma Mimicking Aneurysmal Bone Cyst : A Case Report and Review of Literatures

To present a rare case of a cystic giant schwannoma of the sacrum mimicking aneurysmal bone cyst (ABC). A 54-year-old man visited our institute complaining left leg weakness and sensory change for several years. Magnetic resonance imaging revealed a large multilocular cystic mass with canal invasion and bone erosion confined to left S1 body. The lesion showed multiple septal enhancement without definite solid component. Initially the tumor was considered as ABC. The patient underwent grossly-total tumor resection with lumbosacral reconstruction via posterior approach. The tumor was proved to be a cystic schwannoma. The postoperative course was uneventful and the patient was relieved from preoperative symptoms. We present a rare case of pure cystic giant schwannoma confined to sacrum mimicking ABC. The surgical treatment is challenging due to the complex anatomy of the sacrum. Schwannoma should be considered in the differential diagnosis of osteolytic sacral cysts.     

Fibrous dysplasia in combination with aneurysmal bone cyst presenting as a subarachnoid haemorrhage

Abstract Fibrous dysplasia (FD) is a rare tumour, representing 2.5% of all bone tumours and 7% of benign tumours. Aneurysmal bone cyst (ABC) is also an uncommon pathology, usually associated with a secondary vascular lesion consisting of an arteriovenous malformation. In this article, we relate a case report of a young female with a rare combination of FD with aneurysmal bone cyst presenting as a subarachnoid haemorrhage (SAH). Despite the possibility of clinical treatment of these lesions, this report demonstrates that symptomatic lesions may be successfully managed by surgical resection. The authors’ opinion is that this treatment should be individualised depending on particularities of each case, such as localisation of the lesion, biopsy results and image exams features. We also present a critical literature review of diagnostic methods and therapeutical options for both ABC and FD, with emphasis on controversial topics surrounding these issues.     

Giant intradiploic infratentorial epidermoid cyst

Epidermoid cysts are benign, uncommon lesions (1% of all intracranial tumors). Their localization is intradiploic in 25% of cases, and exceptionally subtentorial. We report here a rare case of giant intradiploic infratentorial epidermoid cyst. A 74-year old patient presented with recent diplopia and sindrome cerebellar. CT scan and MR imaging revealed a giant osteolytic extradural lesion of the posterior fossa (5.2 cm x 3.8 cm) with a small area of peripheral enhancement after contrast injection. Retrosigmoid suboccipital craniectomy allowed a satisfactory removal of the tumor, followed by an acrylic cranioplasty. The outcome was good. Neuropathological examination confirmed an epidermoid cyst. We review the literature and discuss our case.     

Ectopic ventricular recurrence of an epidermoid cyst in the middle fossa.

We present the first case of ectopic ventricular recurrence of an epidermoid cyst in the middle fossa with confirming histological characteristics. A 51-year-old woman presented with an epidermoid cyst in the middle fossa and underwent complete resection. On the 6-month surgical follow-up MRI, a nodular lesion was detected in the frontal horn of the left lateral ventricle without evidence of recurrence at the primary site. The patient underwent transcortial tumor resection. Results of histological studies confirmed that the lesion was an epidermoid cyst similar to the primary lesion. This is a case report of the cerebrospinal fluid spread of an epidermoid cyst, which strengthens the case for special care at the time of surgery to prevent spread of the lesion.     

Aneurysmal bone cyst of the skull

The case of a 6 year old girl with aneurysmal bone cyst (ABC) presenting as a subperiosteal hematoma is reported. Postoperative computerized tomography revealed a new multicystic lesion suggestive of ABC which disappeared spontaneously about 1 month after the operation. The slowly progressing process and spontaneous disappearance of ABC in this case may be noteworthy when considering the surgical indication of this pathology.     

A Ruptured Dermoid Cyst of the Cavernous Sinus Extending into the Posterior Fossa

Supratentorial dermoid cysts are uncommon to develop in the cavernous sinus. We present a ruptured dermoid cyst of the cavernous sinus extending into the posterior fossa. The patient was a 32-year-old female who complained occipital headache, blurred vision, and tinnitus over 4 years. Brain magnetic resonance (MR) imaging revealed an enhanced tumor in the right cavernous sinus extending into the right temporal base and the posterior fossa with findings of ruptured cyst. Surgical resection was performed, and pathological findings were confirmed to be a dermoid cyst. We report a second case with ruptured dermoid cyst of the cavernous sinus extending into the posterior fossa.     

Post-traumatic intradiploic leptomeningeal cyst of the posterior fossa in an adult

Intradiploic cysts in the posterior fossa are rare. We report a post-traumatic intradiploic leptomeningeal cyst in an adult and review the diagnosis and pathogenesis of this lesion.A 28-year-old woman presented with a headache and a hard mass in the occipital region. She had a history of head injury as she had fallen from a height at the age of 18 months. CT scans and MRI revealed an expanding intradiploic cyst with the density of cerebrospinal fluid (CSF) and thinning of the inner and outer tables. A bony defect of the inner table connecting to the cisterna magna was also visualized. At surgery, we detected free communication of the CSF between the cystic cavity and the subarachnoid space of the posterior fossa via a defect in the dura and inner table. The dural defect was sutured primarily and covered with the autogenous outer table.An intradiploic cyst of the occipital bone can be detected in adults and might be caused by remote head injuries during childhood. Prompt surgical repair of the dural and bony defect in an adult patient has an excellent prognosis.     

成人后颅窝巨大蛛网膜囊肿的诊断与手术治疗

目的 探讨成人后颅窝蛛网膜囊肿的诊断和治疗方法.方法 回顾性总结分析10例成人后颅窝巨大蛛网膜囊肿的临床资料和手术效果,10例全部采取开颅囊壁切除造口粘连松解术,并使之与第四脑室和蛛网膜下腔交通,1例同期行颅内多发性硬膜下积液钻孔引流术.结果 所有病人术后恢复良好,出院前症状改善6例,无变化4例.术后1周常规复查头部MRI,囊肿缩小、小脑部分复位6例.3个月后随访复查头部CT,无囊肿复发.其中小脑完全复位4例,大部分复位6例;脑积水消失、脑室恢复正常4例,脑积水减轻6例;临床症状消失7例,好转3例.结论 开颅在显微镜下获得囊肿腔与脑室及蛛网膜下腔的交通是避免后颅窝巨大蛛网膜囊肿复发和治疗脑积水的关键,手术效果良好.     

MR imaging in aneurysmal bone cyst of the orbit

Aneurysmal bone cyst is a benign fibro-osseous lesion usually described in the long bones. Intraorbital aneurysmal bone cyst is a rare clinical entity with an entirely different outcome and prognosis as compared to the usual pediatric orbital tumors. The authors report magnetic resonance imaging (MRI) features of an orbital mass lesion in a 4-year-old child who presented with painless proptosis of right eye. Characteristic MRI findings led to a suspicion of an aneurysmal bone cyst that was totally excised via a right frontotemporal craniotomy. Appreciation of characteristic MRI features can be of extreme help for appropriate diagnosis and management of this rare entity.     

Chondromyxoid fibroma of frontal bone: a case report and review of the literature

Chondromyxoid fibroma is an unusual benign tumor of cartilaginous tissues that may be confused with other some malign tumors. It is rarely seen in the skull. A 45-year-old female was admitted with painless bony swelling in the forehead. Computerized tomography demonstrated a well-defined expansive lesion with a sclerotic margin measuring approximately 3 cm in diameter in the right frontal bone. On MRI, T1-weighted images revealed a well circumscribed, lobulated and strongly enhancing lesion. On the T2-weighted images, the lesion showed high heterogeneous signal intensity. The patient underwent tumor excision with craniectomy, then acrylic cranioplasty. The histopathological diagnosis was chondromyxoid fibroma. There was no recurrence in a period of 22-months. In conclusion, chondromyxoid fibroma is a benign primary bone tumor that is located extremely rarely in the frontal bone. Accurate initial diagnosis of such tumors are important for appropriate treatment. En block surgical resection of the tumor is the cornerstone of treatment.     

Post-traumatic intradiploic leptomeningeal fistula and cyst.

A 59 year old female patient presented with ataxia and difficulty in walking. The neurological examination revealed right homonymous hemianopia and ataxia. Radiographic evaluation revealed a large occipital intradiploic cyst mainly in the left suboccipital area. There was also moderate hydrocephalus and encephalomalacia of the left occipital pole. Bone window studies also demonstrated a growing fracture extending from the upper pole of the cyst to the vertex. Both pathologies were attributed to child abuse the patient suffered when she was a child. At first surgery, decompression of the cerebellum was followed by duroplasty and acrylic cranioplasty to the posterior cranial fossa. A month later, a shunt had to be inserted for hydrocephalus. At 7 months postoperatively, the patient is well and free of any symptoms or recurrence.     

Transcranial cerebellar herniation following craniotomy: Case report and literature review

To report a case of post-surgical encephalocele through craniotomy burr holes following the resection of a meningioma of the posterior fossa. A 49-year-old female presented in the emergency room with cephalea. The MRI showed a meningioma of the convexity of the posterior fossa. A resection was performed and the bone flap replaced. The patient recovered uneventfully and was discharged. After 30 days the patient consulted referring cephalea, vomiting and imbalance. Brain MRI revealed a trans-cranial cerebellar herniation through the craniotomy burr holes. An urgent surgery was performed to repair the encephalocele. Post-surgical brain MRI was performed and did not show complications.Post-surgical encephalocele is an uncommon complication after the resection of a posterior fossa lesion. To avoid this complication, it is recommended thorough dural and bony closure, particularly in the posterior fossa surgeries and in high-risk patients.     

Intracranial aneurysmal bone cyst manifesting as a cerebellar mass

A 17-year-old boy presented with symptoms of raised intracranial pressure for a month. Investigations revealed a large extra-cerebellar mass. The lesion was radically resected. It arose from the petrous bone. Histology revealed that the lesion was an aneurysmal bone cyst [ABC].