Two cases of the epidermoid on the petrous bone

Epidermoids known as cholesteatomas, are congenital benign tumors and originate in the embryonic ectoderm. They account for 1.3% of all intracranial tumors. They are often found in the cerebellopontine angle and the paraseller region, but rarely in the petrous portion of the temporal bone. Epidermoids of the petrous bone tend to slowly present progressive facial palsy and hearing disturbance. In this article, two cases of epidermoids involving the petrous bone are reported. A 55-year-old male presented left facial palsy, left hearing disturbance and decreased gustation in the left side of the tongue. MRI revealed a non-enhanced mass on the petrous portion of the left temporal bone, and bone-window CT showed bone destruction in the same region (Case 1). A 71-year-old female was aware of left facial palsy and left hearing loss for 15 years. MRI showed a non-enhanced mass on the petrous bone, and bone-window CT demonstrated extensive bone erosion of the petrous bone and the middle cranial fossa (Case 2). In both cases, total removal was performed via the middle cranial fossa approach. Both tumors existed extradurally and had pressed against the genicurate ganglion of the facial nerve. The facial palsy of the former case recovered 12 months after surgery. We discuss the problems of diagnosis and treatment of epidermoids of the petrous bone.     

Floating petrous bone fracture

Floating petrous bone fracture appears to occur when the elastic pediatric skull is subjected to large compressive forces. Unlike a longitudinal fracture, a floating petrous bone fracture does not involve the ear canal and squamous cortex. Rather, the fracture line runs through the middle ear, separating the petrous apex from its lateral and inferior bony attachments. Characteristic clinical findings include immediate onset of conductive hearing loss, with ipsilateral sixth and seventh cranial nerve paralysis. This article details the third known occurrence of this type of fracture, and includes a discussion of the pathophysiologic mechanism and treatment rationale.     

岩段颈内动脉的显微解剖及临床意义

目的 了解岩段颈内动脉及其相关结构的显微解剖，为手术操作提供解剖学基础。方法在手术显微镜下观察15例30侧成人头部标本的岩段颈内动脉及相关结构，测量有关数据。结果 岩段颈内动脉分水平段、膝部及垂直段。岩浅大神经的走行基本和岩段颈内动脉水平段平行，是术中确定岩段颈内动脉水平段的重要标志。结论 熟悉岩段颈内动脉的显微解剖及其和相邻结构的关系，就能在相关于术中更好保护岩段颈内动脉，减少并发症，提高手术疗效。     

En Bloc Resection of the Temporal Bone by the Lateral Approach in Carcinoma of the Middle Ear Associated with Skull Base Infiltration with Reference to the Resection of the Petrous Apex

En bloc resection of the temporal bone was performed by the lateral approach on two patients with carcinoma of the middle ear, which was associated with destruction in the temporal bone and tumor infiltration of the cranial base. In one of the patients, the petrous apex was resected along with the temporal bone.

En bloc resection on the temporal bone with the petrous apex is believed to be difficult because the internal carotid artery (ICA), cavernous sinus, and the brainstem are adjacent to each other in the petrous apex. However, the intra- and extracranial surgical procedures by this approach allow resection of the temporal bone ranging from the anterior part including the petrous apex to the posterior part including the mastoid process, the dura of the middle and posterior cranial fossae, and the sigmoid sinus, without exposure of the tumor. Special attention should be paid to the procedural points of surgery, such as, exposure of the petrous ICA, bleeding from the petrous sinus, and dural suturing in the vicinity of the apex. With regard to surgical indication, it is important to determine whether tumor infiltration is confined to the temporal bone and the dura of the middle and posterior fossa. If tumor infiltration into the petrous ICA, the dominant side of sigmoid sinus and/or the inferior cranial nerve is observed, then indication for surgery should be determined in a more critical manner.

     

Giant Cell Reparative Granuloma of the Petrous Temporal Bone: A Case Report and Literature Review

Giant cell reparative granuloma (GCRG) is an unusual, benign bone lesion that most commonly affects the maxilla and mandible; skull involvement is rare. The etiology is uncertain but may be related to trauma. GCRG is difficult to distinguish from giant cell tumor of the bone and has a lower recurrence rate. Thirteen reports of temporal bone GCRG in 11 patients have been reported. One report of a petrous GCRG in a 3-year-old girl has been identified. A 38-year-old male presented with a 2-year history of fullness in his left ear, ipsilateral hearing loss, and intermittent cacosmia. Computed tomography and magnetic resonance imaging revealed a large left-sided anterior temporal extradural mass. The patient underwent a left frontotemporal craniotomy and resection of a left temporal fossa tumor that involved the petrous and squamous parts of the temporal bone. The patient's post-operative course was uneventful, except for increased hearing loss secondary to opening of the epitympanum. Follow-up at one month revealed no other problems. Histopathology of the specimen was consistent with a giant cell reparative granuloma.     

Giant cell reparative granuloma of the petrous temporal bone: a case report and literature review

Giant cell reparative granuloma (GCRG) is an unusual, benign bone lesion that most commonly affects the maxilla and mandible; skull involvement is rare. The etiology is uncertain but may be related to trauma. GCRG is difficult to distinguish from giant cell tumor of the bone and has a lower recurrence rate. Thirteen reports of temporal bone GCRG in 11 patients have been reported. One report of a petrous GCRG in a 3-year-old girl has been identified. A 38-year-old male presented with a 2-year history of fullness in his left ear, ipsilateral hearing loss, and intermittent cacosmia. Computed tomography and magnetic resonance imaging revealed a large left-sided anterior temporal extradural mass. The patient underwent a left frontotemporal craniotomy and resection of a left temporal fossa tumor that involved the petrous and squamous parts of the temporal bone. The patient's post-operative course was uneventful, except for increased hearing loss secondary to opening of the epitympanum. Follow-up at one month revealed no other problems. Histopathology of the specimen was consistent with a giant cell reparative granuloma.     

Mallet Finger Fracture through Enchondroma of the Distal Phalanx

A 46-year-old man injured his ring finger and developed a mallet deformity. Radiographs showed a mallet finger fracture through an osteolytic lesion of the distal phalanx. Magnetic resonance imaging showed low intensity on T1-weighted imaging and high intensity on T2-weighted imaging, which suggested the clinical diagnosis of enchondroma. The bone tumor was excised, and osteosynthesis was performed using Ishiguro''s extension block pinning, and a flexion block pin was added to prevent flexor tendon avulsion fracture through the enchondroma, followed by an autologous iliac cancellous bone graft. One year after surgery, the patient had no pain or extension lag of the affected ring finger, and his quickDASH score was 0 points. Radiographs showed no recurrence and minimal arthritic change of the distal interphalangeal joint. One-stage treatment of a mallet finger fracture through an enchondroma using Ishiguro''s method was effective.     

En bloc resection of the temporal bone by the lateral approach in carcinoma of the middle ear associated with skull base infiltration with reference to the resection of the petrous apex

En bloc resection of the temporal bone was performed by the lateral approach on two patients with carcinoma of the middle ear, which was associated with destruction in the temporal bone and tumor infiltration of the cranial base. In one of the patients, the petrous apex was resected along with the temporal bone.En bloc resection on the temporal bone with the petrous apex is believed to be difficult because the internal carotid artery (ICA), cavernous sinus, and the brainstem are adjacent to each other in the petrous apex. However, the intra- and extracranial surgical procedures by this approach allow resection of the temporal bone ranging from the anterior part including the petrous apex to the posterior part including the mastoid process, the dura of the middle and posterior cranial fossae, and the sigmoid sinus, without exposure of the tumor. Special attention should be paid to the procedural points of surgery, such as, exposure of the petrous ICA, bleeding from the petrous sinus, and dural suturing in the vicinity of the apex. With regard to surgical indication, it is important to determine whether tumor infiltration is confined to the temporal bone and the dura of the middle and posterior fossa. If tumor infiltration into the petrous ICA, the dominant side of sigmoid sinus and/or the inferior cranial nerve is observed, then indication for surgery should be determined in a more critical manner.     

Elevation of the petrous bone caused by hyperplasia of the occipital bone presenting as hemifacial spasm: diagnostic values of magnetic resonance imaging and three-dimensional computed tomographic images in a bone anomaly

A case of elevation of the petrous bone due to hyperplasia of the occipital bone presenting as hemifacial spasm is reported. A 44-year-old man sought treatment for twitching of the buccal muscles on the right side that progressed rapidly in severity within 2 weeks of the onset. The anatomical details of the petrous and occipital bones were delineated clearly by computed tomographic scans of a bone window level. Details of the brain stem were shown by magnetic resonance images. The bone anomaly was displayed more realistically by three-dimensional computed tomographic reconstructions. The faithful representation of structures with these radiological studies should be mandatory, to prepare the surgical planning of such a complicated bone anomaly.     

听神经鞘瘤与三叉神经鞘瘤的快速鉴别诊断

目的 通过影像学分析,选出一个较为可靠且快速鉴别听神经与三叉神经鞘瘤的指标.方法 对47例经手术病理证实的听神经和三叉神经鞘瘤病人影像学资料采用单因素方差分析.结果 38例听神经鞘瘤除1例肿瘤体积巨大外,其余病例瘤体均未骑跨或未达到岩骨尖部;9例三叉神经鞘瘤除1例肿瘤较小外,其余均骑跨或半骑跨岩尖部(即跨中后颅凹).结...     

Combined Approach for Lesions Involving the Cerebellopontine Angle and Skull Base: Experience with 30 Cases

This article presents a series of 30 patients who underwent a combination of the subtemporal and posterior fossa approaches for exposure of lesions in the clivus or medial petrous region. This combined supra- and infratentorial approach is divided into three variations with progressively greater petrous bone resection to increase exposure of the clivus and medial petrous region. The approach has been divided into petrous bone resection with preservation of hearing (retrolabyrinthine), greater petrous bone resection with sacrifice of hearing (translabyrinthine), and finally maximum petrous drilling with sacrifice of hearing along with transposition of the facial nerve (transcochlear). Ninety-three percent of the cases returned to their premorbid occupations.     

Computed tomography evaluation of air cells in the petrous bone--relationship with postoperative cerebrospinal fluid rhinorrhea

The anatomy of air cells in the petrous bone was investigated using thin-slice bone-window computed tomography (CT) of 168 petrous bones in 84 patients. Air cells in the petrous bone were classified into mastoid and petrous cells. Petrous cells were subdivided into perilabyrinthine and apical cells. Perilabyrinthine cells comprised supralabyrinthine and infralabyrinthine cells. Supralabyrinthine cells were subdivided into posterosuperior, posteromedial, and subarcuate cells. The mastoid was classified as eburnated (11%) or pneumatized (89%) by the extent of the mastoid cells. The mastoid cells were classified into presinusoidal (14%), sinusoidal (44%), and postsinusoidal (42%) according to the relationship with the sigmoid sulcus. The extent of the mastoid cells was significantly correlated with the pneumatization of the petrous apex, i.e. the apical cells (p < 0.01). CT precisely depicted the complex anatomy of the air cells in the petrous bone. Cerebrospinal fluid (CSF) rhinorrhea is the most common complication after skull base surgery for cerebellopontine angle tumors. Air cells in the petrous bone provide the route for CSF rhinorrhea. Therefore, CT assessment of the air cells is useful for preventing this complication.     

Combined approach for lesions involving the cerebellopontine angle and skull base: experience with 30 cases

This article presents a series of 30 patients who underwent a combination of the subtemporal and posterior fossa approaches for exposure of lesions in the clivus or medial petrous region. This combined supra- and infratentorial approach is divided into three variations with progressively greater petrous bone resection to increase exposure of the clivus and medial petrous region. The approach has been divided into petrous bone resection with preservation of hearing (retrolabyrinthine), greater petrous bone resection with sacrifice of hearing (translabyrinthine), and finally maximum petrous drilling with sacrifice of hearing along with transposition of the facial nerve (transcochlear). Ninety-three percent of the cases returned to their premorbid occupations.     

Primary Ewing sarcoma of the petrous temporal bone: an exceptional cause of facial palsy and deafness in a nursling

BACKGROUND: Primary Ewing sarcoma affecting the skull base in general and the petrous bone in particular is extremely rare with only 4 reports of Ewing sarcoma arising in the petrous temporal bone in the international medical literature. METHODS: The authors report for the first time a case of a primary Ewing sarcoma of the petrous temporal bone in a 5-month-old nursling, which became apparent with a complete peripheral facial palsy and ipsilateral surdity. RESULTS: The neoformation was treated by systemic chemotherapy and radiation of the tumor region. The diagnostic steps, therapy, and development of the child are described in detail; the literature concerning Ewing sarcoma originating from the skull in general and from the petrous temporal bone in particular is reviewed. CONCLUSIONS: The highlights of this case are an extremely uncommon location, an unusual age of presentation, as well as a unique set of symptoms.     

A renal transplant recipient with pulmonary tuberculosis and visceral leishmaniasis: review of superimposed infections and therapy approaches

Visceral leishmaniasis (VL) is an acute or subacute disease that is almost invariably fatal if untreated. It is a rare disease in renal transplant recipients and frequently reported together with other infectious agents. A 39-year-old renal transplant patient was admitted to hospital for elective coronary surgery. In the post-operative period, he developed spiking fever and non-productive cough and his general condition deteriorated. While he was taking medication for non-specific pneumonia, a cavitary lesion occurred in his lung, and he had the diagnosis of pulmonary tuberculosis and antituberculous treatment was started. Despite treatment, his fever continued. As the patient developed pancytopenia and splenomegaly, a bone marrow aspiration was done. Evaluation of bone marrow aspirate indicated Leishmania parasites. He was successfully treated with a more intensive liposomal amphotericin (L-AmB). Complete cure was achieved during follow-up period of 10 months without clinical relapse. In the existence of fever and long-standing pancytopenia, VL should be suspected although the patient had another proved infection and did not live or visit an endemic area. L-AmB usage can be safely preferred for treatment of selected renal transplant recipients with VL as first-line therapy.     

Epidermoid tumor originating from the petrous bone: report of two cases

In case 1, the tumor was incidentally found in the right petrous bone, middle cranial fossa and cerebello-pontine angle. T1 weighted MRI demonstrated a low intense mass and T2 weighted imaging demonstrated hyperintensity. Through the subtemporal extradural approach, an epidermoid in the middle cranial fossa was partially removed. Postoperative course was uneventfull but an episode of rhinorrhea occurred 15 months later. Bone-window CT scan disclosed air cells of the petrous bone were exposed to the previous surgical cavity. Using the same approach, an epidermoid was totally removed. With the sealing of the tumor cavity with the vascularized muscle flap, the patient became free from rhinorrhea. Case 2 had complainted of sensory impairment in the left trigeminal nerve distribution, atrophy of the left temporal and masseter muscle, and diplopia. T1 weighted imaging of MRI demonstrated a low-intense mass in the left petrous bone, middle cranial fossa, temporal lobe, and cerebello-pontine angle, and T2 weighted imaging demonstrated hyperintensity. The intradural tumor under the temporal lobe was removed at another hospital. As the diplopia deteriorated 5 years later, the patient was re-introduced to our hospital. At first, the tumor in the cerebello-pontine angle was removed using the left retromastoid lateral suboccipital approach. Later, the tumor in the petrous bone and middle cranial fossa was removed through the left subtemporal extradural approach. With the sealing of the tumor cavity with the vascularized muscle flap, postoperative cerebrospinal fluid leakage was prevented. The epidermoid tumor in the petrous apex is a congenital and rare disease. The obstruction of the petrous air cell and dural defect using the vascularized flap is most important to prevent postoperative cerebrospinal fluid leakage.     

Surgical resection of large and giant petroclival meningiomas via a modified anterior transpetrous approach

The authors describe a modified anterior transpetrous approach (ATPA) for the surgical resection of 21 cases of petroclival meningiomas (PCMs). Briefly, a curved periauricular skin incision was used. The cerebellar tentorium and the dura on the petrous apex were coagulated and incised to expose the petrous apex bone fully. The drilling of the petrous apex bone was performed subdurally and began internally from the trigeminal impression, not exceeding 1.5 cm laterally, not exceeding 6 mm from the posterior edge of the petrous ridge, and not exceeding 8 mm in depth from the surface of the petrous bone. The tumors were removed totally in 12 (57.1 %) cases, subtotally in 8 (38.1 %) cases, and partially in 1 (4.8 %) case. The transient neurological deficit includes mild oculomotor nerve palsy in three cases, abducens nerve palsy in six cases, language disorder in three cases, and mild hemiplegia in two cases. Facial numbness became worse postoperatively in six patients, and only two patients improved at 6 months after surgery. No death occurred in this series. The modified ATPA is an efficient treatment alterative for large or giant PCMs located at the medial and superior internal acoustic meatus with relatively low risk of complications.     

Microsurgical Localization of the Cochlea in the Extended Middle Fossa Approach

Objective In the extended middle fossa approach, a portion of the petrous bone known as Kawase''s rhomboid can be drilled to expose the posterior fossa through a middle fossa corridor. During this bony resection, the cochlea is placed at risk. The objective of this study was to objectively detail the position of the cochlea in relation to reliable surgical landmarks.Methods Eleven cadaveric specimens were dissected—including six cadaveric heads and five dry temporal bones by means of an anterior petrosectomy with skeletonization of the cochlea. Three anatomic measurements describing the location of the cochlea in relation to the extrapolated intersection of the greater superficial petrosal nerve (GSPN) and facial nerve were recorded. These measurements were then correlated with thin-cut temporal bone computed tomography scans from 25 patients with morphologically normal inner ears.Results In the cadaveric specimens, the anterior border of the membranous basal turn of the cochlea was located an average of 7.56 mm (6.4 to 8.9 mm) anterior to the extrapolated junction of the GSPN and facial nerve, as measured along the course of the GSPN. The medial border of the membranous cochlea (medial margin of basal turn) was located an average of 8.2 mm (6.9 to 8.9 mm) medial to the extrapolated junction of the GSPN and facial nerve, as measured along the course of the facial nerve. The average maximum distance from the extrapolated junction of the GSPN and facial nerve to the membranous cochlea was 9.3 mm (8.2 to 10.3 mm). These anatomic measurements correlated well with radiologic measurements of the same parameters.Conclusion When drilling Kawase''s rhomboid, it is useful to locate the extrapolated junction of the GSPN and the facial nerve. Drilling of the anteromedial petrous bone outside of a radius of 12.5 mm from the extrapolated junction of GSPN and facial nerve appears to be associated with a low degree of risk to the cochlear apparatus.     

The combined subtemporal-suboccipital approach: a modified surgical access to the clivus and petrous apex.

OBJECTIVE: The surgical access to the clivus and the petrous apex is still a challenge. A combined approach is best fitted to lesions located in the middle and posterior cranial fossa. The approach described is centered on the petrous bone and requires an extensive bone resection; nevertheless, no osteoplastic bone flap is necessary. METHODS: In contrast to approaches described before, the petrous bone is drilled away anterior to the sigmoid sinus more extensively, the sinus is unroofed. For exposure of the middle cranial fossa the petrous bone should be resected down to the roof of the external meatus, the total extent of the craniotomy is significantly smaller. RESULTS AND CONCLUSION: The surgical access as described above provides a wide operative field under preservation of important intracranial structures. This modified approach minimizes the cerebellar and temporal lobe retraction. The neural and vascular structures can be preserved under direct vision to the tumor. The blood supply is interrupted at the beginning of the operation.     

The Passing of the Baton—In Memory of Professor Harry Genant MD

With Dr Harry K. Genant's untimely passing, we note the contributions he made to the field of osteoporosis and bone densitometry including the clinical introduction of quantitative computed tomography, bone densitometry systems validations, universal standards for bone measurement, vertebral fracture assessment, and as a mentor and colleague to countless current clinical and research leaders in the field of osteoporosis. His full biographical sketch is included with remembrances by many of his friends and colleagues on how these innovations came about and shaped the field as it is today.