[Mandibular hemangiopericytoma, a malignant vascular tumor]. / L'hémangiopéricytome mandibulaire, une tumeur vasculaire maligne.

INTRODUCTION: Hemangiopericytoma is a rare tumor, arising from pericytes, which are perivascular cells belonging to the capillar walls. OBSERVATION: A 41 year old man consulted for a mandibular tumor. The clinical and radiographic diagnosis was difficult. The biopsy performed in the operative room led to an embolization decided in emergency, and proved the definitive diagnosis. Despite the embolization, bleeding during surgical excision of the tumor compelled us to perform an external carotid artery ligature. The mandibular reconstruction was performed using a trapezium osteo-muscular flap. DISCUSSION: As reported in the literature, the radiographic diagnosis of hemangiopericytoma is difficult, the malignant potential is variable and the recommended treatment is surgical excision.

Temporal bone density measurements using CT in otosclerosis.

OBJECTIVE: To assess the bone density around the bony labyrinth in otosclerosis patients and to compare it to that of a control population. MATERIAL AND METHODS: This was a prospective case-control study. Ten patients with otosclerosis (mean age 42 years; range 24-55 years) and 33 control patients with vestibular schwannoma (mean age 46 years; range 20-71 years) were included. All patients underwent a clinical examination, audiometry and a CT scan comprising axial and coronal views of both temporal bones. In the otosclerosis group, audiometry showed unilateral involvement in six patients and bilateral hearing loss in four. The bone density was measured at the fissula ante fenestram (FAF) and at five other anatomical points on the bony labyrinth. RESULTS: In the control group, the bone density was similar at the six anatomical points. In the otosclerosis patients, the mean bone density at the FAF was lower than that in control patients (1649+/-99.1 vs 2049+/-13.4 HU; p < 0.01). For patients with FAF bone densities < 2000 HU, a correlation was observed between hearing threshold and FAF bone density. CONCLUSION: FAF bone density appears to be a good indicator of disease progression, and could serve as a follow-up and prognostic parameter.

[Progressive bilateral hearing loss with superficial hemosiderosis of the central nervous system: contribution of cochlear implantation]. / La surdité dans l'hémosidérose superficielle du système nerveux central. Intérêt de l'implantation cochléaire.

Two cases of progressive bilateral hearing loss associated with superficial hemosiderosis of the central nervous system are reported. This is a rare disease caused by repetitive hemorrhage in subarachnoid spaces with hemosiderin deposits on the brain surface and cranial nerves. MRI provided the etiologic diagnosis in both cases based on typical low-density signals from the brain, the brainstem, and the cerebellar surfaces on T1 and T2 sequences. In one case a fourth ventricle ependymoma, which was the probable cause of hemosiderosis, was also discovered. Based on a literature review, we discuss the pathophysiological hypotheses, the modalities for treating hearing loss including cochlear implantation despite retrocochlear sensorineural hearing loss.

[Sudden bilateral hearing loss disclosing meningeal carcinomatosis]. / Surdité brusque bilatérale révélatrice d'une carcinomatose méningée.

We report the case of a patient presenting a sudden bilateral hearing loss. Four years before, a bladder carcinoma was resected and a chemotherapy was started. Gadolinium-enhanced magnetic resonance images revealed enhancement of both acoustic nerves. Cerebrospinal fluid analysis showed malignant cells consistent with the initial bladder cancer. Meningeal metastases from bladder carcinoma are extremely rare. Systemic chemotherapy and its low meningeal diffusion may enhance the incidence of this complication. Bilateral hearing loss is a rare initial manifestation of meningeal carcinomatosis.

[Otosclerosis surgical techniques and results in 150 patients]. / Otospongiose: techniques chirurgicales et résultats. A propos de 150 cases.

OBJECTIVES: To analyze outcome after otosclerosis surgery with stamedeotomy with blood clot sealing. PATIENTS AND METHODS: Otosclerosis surgery was performed in 150 adult patients between 1997 and 1999 by five surgical teams (70% of the procedures were performed by senior surgeons) and followed for 18 months. Stapedotomy was carried out under general anesthesia with an intrameatal approach in 96% of the cases. Stapedotomy (n=120, 80%) was performed with a drill in 141 cases and by laser in 9 (6%). Ninety percent of the Teflon prostheses had a 0.4 mm diameter and a 4.5 mm length. The footplate opening was sealed with blood clots. Venous interposition (n=30, 20%) was performed in the event of partial or total stapedectomy which occurred in spite of an initial stapedotomy attempt. RESULTS: The preoperative air-bone gap (ABG) was 32 +/- 10.3 dB. The gain in air conduction was 25 +/- 11.7 dB with 75% of the patients having more than 15 dB gain. The ABG was 10 +/- 5.4 dB with 73% of the patients having less than 5 dB gain. The interaural difference was 0.5 +/- 14.1 dB and the bone conduction (BC) variation was 1 +/- 7.5 dB. Functional failures were related to significant intralabyrinthine bleeding and revision procedure. The following factors had not effect on outcome: i) stapedotomy versus partial or total stapedectomy, footplate opening sealed by clots or vein, ii) diameter of the stapedotomy and/or the prosthesis, iii) surgical procedure performed by a junior surgeon. CONCLUSION: Sealing the stapedotomy opening with blood clots appears to provide reliable and reproducible functional outcome that remains stable over time. In this study, changing from partial to total stapedectomy with vein interposition did not modify the functional outcome.

Extraaxial primitive neuroectodermal tumor mimicking a vestibular schwannoma: diagnostic and therapeutic difficulties. Report of two cases.

Extraaxial cerebellopontine angle (CPA) medulloblastomas and other primitive neuroectodermal tumors (PNETs) are rare tumors. The authors report on two patients with PNETs who presented with progressive audiovestibular symptoms. In each case magnetic resonance (MR) imaging revealed an extraaxial lesion that filled the internal auditory meatus and exhibited the neuroimaging features of a vestibular schwannoma (VS). No high signal intensity was apparent in either the brainstem or adjacent cerebellum on T2-weighted MR images. Surgery with maximum resection (total in one case and subtotal in the other) was performed, followed by craniospinal radiotherapy. One year postoperatively, both patients were free from tumor. A CPA PNET mimicking a VS is a rare entity, the diagnosis of which is important because its treatment differs dramatically from that of VS, including prescribed surgery followed by conventional craniospinal radiotherapy.

Hypertrophic neuropathy of the facial nerve.

Hypertrophic neuropathy is a peripheral nerve lesion that is histologically characterized by onion bulb formations around axons. This histologic picture, which is usually seen in generalized hypertrophic neuropathies, can occasionally be observed in single nerves as localized hypertrophic neuropathy. Cranial involvement of such localized hypertrophic neuropathy represents a very rare entity; only a few cases have been reported in the literature. We report the history of a progressive facial paralysis with a tumorous enlargement of the seventh cranial nerve that was clinically suspected of being a schwannoma. Pathological examination permitted the diagnosis of hypertrophic neuropathy.

MRI of unusual lesions in the internal auditory canal.

We report the MRI findings of six unusual lesions of the internal auditory canal: three haemangiomas, one lipoma, one metastasis and one traumatic neuroma. We compare the findings to those of 20 intracanalicular schwannomas. We noted the site and size of the tumour, its signal intensity, borders and the homogeneity of enhancement were studied on T1-weighted images before and after intravenous contrast medium and T2-weighted images. Most schwannomas were homogeneous lesions, isointense on T1- and T2-weighted images, and strongly enhancing. Spontaneous high signal on T1-weighted images, heterogeneous contrast enhancement and extranodular enhancement were helpful for recognising lesions other then schwannomas; site, size and signal on T2-weighted images were not. All the haemangiomas had a specific pattern of contrast enhancement, with an anterior core intensely enhancing portion and a posterior portion which enhanced moderately or not at all.

[Endolymphatic sac tumor: a rare tumor of internal ear. Report of two cases]. / Tumeur du sac endolymphatique: tumeur rare de l'oreille interne. A propos de deux observations.

Papillary tumors of the temporal bone are rare and aggressive neoplasms. Recently described, these tumors had initially a presumed middle-ear origin. Only recently, convincing anatomic, morphological and immunohistochemical arguments exist for an endolymphatic sac origin (inner-ear origin). We report two cases of endolymphatic sac tumor. These tumors can be encountered sporadically or in Von Hippel-Lindau disease. They classically grow very slowly, resulting in late clinical manifestations with expansive mass invading temporal bone and extending in posterior fossa. Radiologically, these endolymphatic sac tumors can mimic metastatic carcinoma, paraganglioma, or cerebellar haemangioblastoma specially in von Hippel-Lindau disease. Histology shows a papillary epithelial tumor with hypervascular stroma, without atypia. The treatment for these tumors is surgical and curative when early diagnosed. In apparently sporadic cases, genetic analysis for Von Hippel-Lindau disease should be considered.

[Infralabyrinthine approach for cholesterol granuloma of the petrous apex]. / Granulomes à cholestérine de l'apex pétreux : intérêt du drainage par voie infra-labyrinthique.

Cholesterol granuloma of the petrous apex are cystic lesions, revealed by otologic and/or cranial nerve palsies, and diagnosed with the help of computed tomography and magnetic resonance imaging. Surgical treatment is not the complete removal of the lesion, but a conservative approach requiring drainage of the cyst and re-establishment of a correct aeration of the cavity. Three cases of cholesterol granuloma of the petrous apex were treated through a transmastoid infralabyrinthine procedure. Through a postauricular approach, a simple mastoidectomy was performed. The third portion of the facial nerve was identified. The posterior and lateral semicircular canals, and the jugular bulb were skeletonized. In two cases, a high diverticulum of the jugular bulb was impacted downwards with wax. The cystic lesion was then opened, and evacuated. The opening must be large to permit a correct aeration of the cavity and prevent stenosis of the drainage site. Hearing and the facial function were preserved in all cases. In conclusion, conservative approach to cholesterol granuloma of the petrous apex provides satisfactory drainage of this intrapetrous deep seated lesion with preservation of hearing and facial nerve function.

[Imaging of the cerebello-pontine angle and skull base]. / Imagerie de l'angle ponto-cérébelleux et de la base du crâne.

Lesions of the internal auditory meatus, cerebello-pontine angle and skull base have benefited greatly from the progress made in imaging techniques. There are now three methods of examination at our disposal. MRI scan is the primary method of choice, and includes T1 spin echo sequences without and with the injection of contrast, and the T2-weighted sequence (with spin echo or gradient echo CISS-3DFT); other sequences, such as angio-MRI and FLAIR, are used more rarely. CTscanning is complementary to MRI, but gives a better definition of bony structures. Arteriography is more rarely indicated. Imaging usually allows a diagnosis of the type of lesion encountered. The typical features on MRI and CT scan of the various pathological lesions of the internal auditory meatus, cerebello-pontine angle and skull base are discussed, together with the fact that by far the commonest among them is the vestibular neuroma.

Cervicomediastinal magnetic resonance imaging in persistent or recurrent papillary thyroid carcinoma: clinical use and limits.

Cervicomediastinal magnetic resonance imaging (MRI) was evaluated in 13 consecutive persistent or recurrent papillary thyroid carcinoma (PTC) patients, previously treated by total thyroidectomy and radioiodine ablation. All had elevated thyroglobulin (Tg) levels and were therefore submitted to a new therapeutic radioiodine dose followed by a posttherapeutic whole-body scan (131I-WBS) and subsequent MRI. Patients with known distant metastases were excluded from the study. Group 1 included 7 patients with a negative 131I-WBS, whereas cervical and/or mediastinal 131I-uptake was evidenced in the other 6 patients (group 2). MRI was thus compared to 131I-WBS, and additionally in 8 reoperated cases, to histology. MRI was positive in 11 of 13 (85%) patients, corresponding to 23 of 55 (41.8%) histologically confirmed sites. In group 1, MRI was positive in 5 of 7 patients, with a sensitivity of 47% (15/32 histologically positive sites), allowing appropriate indication of surgery: 4 neck surgery, and 1 mediastinal dissection because of too distant lymph node foci. In group 2, MRI always showed more localization than 131I-WBS; histology was obtained in 3. Because all the foci located in the mediastinal area (0.8 to 1.8 cm) were histologically confirmed (7/7 sites), MRI avoided underestimation of surgery in the 8 reoperated patients. However, additional images were also observed corresponding to a normal thymus, a small neuroma or inflammatory lymph nodes, but pretracheal and very small nodes (less than 0.5 cm) were missed. In conclusion, although less specific than radioiodine scintigraphy, MRI can detect local persistent or recurrent PTC, and seems particularly effective for evaluation of mediastinal involvement.

[Cervico-mediastinal recurrences of differentiated thyroid cancers: value of MRI]. / Récidives cervico-médiastinales des cancers thyroïdiens différenciés: valeur de l'irm.

AIM: The aim of this study was to evaluate the ability of MRI to detect recurrent differentiated thyroid carcinomas developed in the neck or the upper mediastinum. RESULTS: MRI was performed in 25 patients, and was compared in 5 cases with surgery. In 20 cases it was compared with I-131 scintigraphy (100 mCi in 14 cases and 5 mCi in 6 cases). The sensibility, specificity and overall accuracy of MRI was respectively: 100%, 66.6%, 82.6%. COMMENTARY: MRI is a good technique to detect recurrent thyroid carcinomas. It is specially interesting to investigate patients with a biological suspicion of recurrence and a negative scintigraphy. Mediastinal localisations that cannot be detected by US can be detected by MRI.

MR imaging of breast hemangioma in female infants.

Breast hemangioma in female infants is a rare benign lesion, prone to spontaneous regression. But when the lesion regresses there is a risk of breast atrophy if the breast bud is included in or very close to the hemangioma. A trial of corticosteroid therapy could be proposed to prevent this risk, but one must be sure that the breast bud is included in or very close to the hemangioma before treatment. We studied 4 children with breast hemangioma to evaluate the ability of MR Imaging in the diagnosis of breast bud inclusion. 0.5 Tesla axial Spin Echo T2-weighted images (TR = 2000 ms; TE = 120 ms) clearly depicted interface between high signal appearance of hemangioma and hypo-intensity of the breast bud: in our four patients we were able to determine whether or not the hemangioma involved the breast bud. Our preliminary study seems to demonstrate that MR imaging is a valuable imaging technique to determine which patients could be eligible for a trial of corticosteroid therapy.

[From lymphangioma to lymphangiomatosis. Apropos of 10 cases]. / Du lymphangiome à la lymphangiomatose. A propos de 10 observations.

Seven cases of lymphangioma and 3 cases of diffuse lymphangiomatosis have been studied with computed tomography (CT). In the 7 cases of local involvement, the tumor was located in the mediastinum (3 cases), the mesentery (2 cases), the spleen (1 case), and the pelvis (1 case). The disease was diffuse in 3 cases, involving the mesentery, the pelvis, the posterior mediastinum, the retroperitoneal space and the bones in the first case; in the second case, lymphangiomatosis was located in the posterior mediastinum, the spine (T12 and L3) and the right iliac wing; the third case showed diffuse involvement of the posterior mediastinum and of the spleen. The CT study allows suspecting the disease when it demonstrates an encapsulated tumor with liquid or fatty density and thin walls enhancing with contrast. Other, less typical appearances may be observed, which should not lead to challenging this diagnosis. The CT exploration provides a complete assessment of the lesions, including the detection of tumors not seen on plain radiographs. In addition, CT is useful for the prognosis since it identifies the diffuse forms, which are naturally prone to aggravation, or recurrence when surgery has been indicated. Lymphangioma and lymphangiomatosis seem to be different forms of the same abnormality of the lymphatic system, either local or scattered.