Intracranial plasma cell granuloma

We report two rare cases of primary intracranial plasma cell granuloma. The tumors probably arose from the dura and involved the cerebral parenchyma. These patients presented with clinical features of raised intracranial pressure and there was focal neurological deficit. The management issues are discussed.     

改良部分迷路切除岩骨尖入路的岩骨磨除技术

目的探讨改良部分迷路切除岩骨尖入路(PLPA)的岩骨磨除技术。方法测量10例(20侧)成人干颅骨标本骨性结构间的距离;对15例(30侧)成人尸头采用PLPA及改良PLPA暴露岩斜区,观察岩斜区解剖结构的暴露情况及有无岩骨内重要结构的损伤,测量骨窗大小及增加的视野、视角,对结果进行统计学分析。结果岩浅大神经沟到岩骨嵴的平均距离为12.8m m,D onaldson线到岩骨嵴的平均距离为12.2m m,所有标本均未损伤岩骨段颈内动脉等重要结构。改良PLPA可充分暴露岩斜区。改良PLPA较PLPA骨窗小,差异有高度统计学意义(P<0.01);磨除骨质后两入路增加的手术视野和视角无统计学差异(P>0.05)。结论改良PLPA较PLPA创伤小,暴露同样充分。岩骨磨除操作是改良PLPA的关键技术,不容易损伤岩骨内重要结构,有可能保留听力;D onaldson线可作为磨除岩骨的安全界限。     

Low-dose high-resolution CT of the petrous bone

PURPOSE: To show that CT of the petrous bone can be realized using a low-dose technique. MATERIAL: and methods: A high-contrast phantom was scanned with 1.5 mm slice thickness and 60-510 mAs using the reconstruction algorithms standard, bone and edge. In 50 patients, the petrous bone was examined using the standard protocol at 510 mAS. Additionally, selected slices were made at 120 or 210 mAs. The resolution of relevant structures was compared. Phantom studies were repeated on a second CT-device; images of patients scanned with 80 mAs were analyzed in regard to resolution of osseous details. RESULTS: With the first CT-device structures of the phantom up to 0. 5 mm were depicted using 510 mAs and the edge kernel. With 120 mAs and the bone kernel structures of 0.6 mm could be distinguished. Although the same resolution was achieved with 60 mAs and the edge kernel, patient examinations showed a profound image noise. The results achieved with 120 mAs and the bone algorithm, however, were equal to that of 510 mAs. With the second device the same image quality was realized with only 80 mAs. CONCLUSION: CT-examinations of the petrous bone can be effected without loss of diagnostic information using only 15% of the radiation dose used for a standard brain examination.     

Endolymphatic sac carcinoma of the right petrous bone in Von Hippel-Lindau disease.

A large endolymphatic sac papillary adenocarcinoma in a patient with Von Hippel-Lindau (vHL) disease is reported. A 31-year-old man was treated for a left eye retinal angioma 10 years previously and had been blind in that eye since. He was admitted with progressive tinnitus, lower cranial nerve paresis and ataxia. Investigations revealed a vascular and bone-eroding petrous tumour. The entirely extradural tumour involved a large part of the petrous bone and extended into the cerebellopontine angle. The vascular tumour was radically resected using a presigmoid approach after feeding vessel embolisation. The literature on this rare clinical entity is briefly discussed.     

Facial nerve palsy due to cavernous angioma of the petrous bone. Case report

The facial nerve palsy due to extrinsic tumoral compression of the facial nerve at the geniculate ganglium is very rare. We present the case of a patient with a temporal bone cavernoma and symptoms of a torpid peripheral facial House-Brackmann grade IV nerve palsy with dry eye and loss of stapedial reflex. The routine computed tomographic and magnetic resonance imaging studies showed no abnormalities, but the same imaging techniques done after the clinical suspiction identified a less that 1cm lesion that was compatible with an osseous cavernous angioma. The lesion was approached and removed through a microsurgical middle fossa extradural approach with a good postoperative recovery (House-Brackmann grade II).     

颞骨岩部和乳突部的显微解剖研究

目的 研究颞骨岩部和乳突部的解剖,为岩斜区手术入路提供解剖学依据.方法 成人颅骨标本10例;10例10％甲醛溶液固定的成人湿头颅标本.在手术显微镜下观察,测量颞骨岩部、乳突部外侧面星点、顶乳突缝前角、乙状窦横窦之间的距离,观察乙状窦沟上曲在颅外的标志点.结果 乙状窦沟上曲转角上缘有80％在颅外对应点是顶乳缝前角;上曲转角下缘有75％在颅外对应点是星点前下方约4.67 mm.结论 顶乳缝前角、星点是幕上下联合开颅的两个关键孔,合理地利用两个关键孔可以减少术中副损伤及术后并发症的发生.     

颅内浆细胞肉芽肿(附五例报告及文献复习)

目的 探讨中枢神经系统浆细胞肉芽肿的诊断及治疗。方法 对我院1997年1月至2002年3月收治的5例颅内浆细胞肉芽肿的临床资料进行回顾性分析。结果 5例病人，2例位于左顶叶，余3例分别位于右颞叶、右额叶和枕骨大孔区，头CT显示为高密度，MRI为长或等T1、长T2信号，注射造影剂后明显增强。术前诊断为脑转移瘤、脑囊虫病、脑脓肿和脑膜瘤，术后经病理和免疫组化染色发现肿物主要由3种成熟的细胞组成，即浆细胞、淋巴细胞和组织细胞，以浆细胞为主，浆细胞胞浆内κ、γ轻链均呈阳性表达。手术切除后给予激素治疗，预后良好。结论 颅内浆细胞肉芽肿少见，易引起误诊，免疫组化检查有助于鉴别诊断，手术切除和激素治疗效果较好。     

Pediatric giant cell granuloma of the temporal bone: a case report and brief review of the literature.

Giant cell granuloma of the skull base is a distinct rare clinicopathologic lesion, which progressively destroys the involved bone. It causes increased intracranial pressure and mass effect on the brain. Histologically it may mimic an aneurysmal bone cyst, giant cell tumour and the brown tumour of hyperparathyroidism. Although cited by some authors, the role of trauma in its aetiology is still considered controversial. Authors present an interesting case of a 12 year old Omani boy who sustained a cricket bat injury to his right temporal region from which he initially recovered but later on progressively developed vertigo, tinnitus, right hearing loss and a mild right facial weakness. Computed tomography (CT scan) and Magnetic resonance imaging (MR scan) revealed a large destructive lesion of the temporal bone. Microsurgical excision was curative. Interesting clinicoradiological findings are presented with a brief review of the literature.     

Eosinophilic granuloma of the occipital bone presenting as intracranial venous hypertension.

Intracranial venous sinus thrombosis is an uncommon cause of pseudotumor cerebri. The diagnosis is often not confirmed on the rationale that treatment will not be altered. We report a case presenting a pseudotumor cerebri where the underlying pathology disclosed dural sinus thrombosis resulting from compression by an eosinophilic granuloma of the occipital bone. Routine CT of the head and Technetium-99m brain scan initially demonstrated neither tumor nor thrombosis. Plain skull x-rays subsequently revealed a lytic lesion of the occiput. When reinvestigated with CT using bone density windows the tumor was revealed. Excision of the tumor and a short course of cobalt therapy was curative. Special techniques in nuclear scanning, CT and MRI designed to improve the sensitivity for diagnosing venous sinus thrombosis are described. This case illustrates the importance of establishing a definitive diagnosis and shows the importance of pre-test consultation between clinicians and radiologists to ensure that specific investigative techniques are properly utilized.     

Eosinophilic granuloma of bone: Two case reports

Eosinophilic granuloma (EG) is a benign, self-limiting disorder that usually involves a single bone. However, there is a growing evidence that the clinical picture of EG is protean. We report two cases with EG that showed rare presentations.     

经颞下入路磨除岩骨虚拟现实模拟研究

目的对比分析尸头标本和虚拟现实系统经颞下入路磨除岩骨解剖显露特征,探讨虚拟现实技术在岩骨显微解剖中的应用价值。方法将15例成人尸头标本CT影像数据输入Dextroscope虚拟现实系统,构建岩骨三维解剖模型,分别于尸头标本和虚拟现实系统中模拟经颞下入路磨除岩骨手术方法,逐步显露解剖结构,选择标志点进行距离和角度测量。采用Bland-Altman方法进行一致性检验。结果虚拟现实系统模拟经颞下入路磨除岩骨可视性效果良好,岩骨内面神经、岩浅大神经、耳蜗、半规管、颈内动脉、颈静脉球等解剖结构显示清晰。分别于尸头标本和虚拟现实系统中测量并获得膝状神经节半规管总骨脚起始点、膝状神经节耳蜗顶点和耳蜗顶点岩骨内颈内动脉水平段起始点连线距离,经Bland-Altman检验,偏倚分别为0.020、0.020和0.010,95%可信区间分别为0.240～0.270、0.190～0.220和0.170～0.150,相关分析显示一致性良好。尸头标本因角度限制无法测量半规管总骨脚起始点颈静脉球上缘连线距离和内耳道与岩浅大神经沟夹角角度,而虚拟现实系统岩骨解剖模型数据测量方便快捷,无测量角度限制,测得半规管总骨脚起始点与颈静脉球上缘连线距离为(4.74±0.20)mm、内耳道与岩浅大神经沟夹角角度为(51.34±3.29)°。结论利用虚拟现实技术模拟经颞下入路磨除岩骨的手术方法,方便快捷,所获数据准确、直观并可量化,可为指导岩斜区病变神经外科手术提供依据。     

Primary Ewing's sarcoma of the petroclival bone.

A 17-year-old male presented with signs of raised intracranial tension and multiple cranial nerve dysfunction. Radiological imaging revealed an extradural calcified tumor involving the right petrous bone and adjacent clivus. The patient underwent extensive surgical debulking of the mass. Histopathological study revealed that the tumor was Ewing's sarcoma. Post-operative radio- and chemotherapy were administered. The patient's cranial nerve dysfunctions had recovered to some extend at 12 months' follow-up. Ewing's sarcoma arising from the skull base is an extremely rare lesion. The relevant literature on the subject is reviewed.