60例咽旁隙肿块的CT及MRI影像学特征分析

目的探讨咽旁隙肿块的CT及MRI表现,了解其影像学特征。方法回顾性分析2014年6月~2016年6月收治的60例咽旁隙肿块患者的CT及MRI影像学特征,观察肿块的位置、形态、与周围组织关系、密度、信号高低等情况。结果在60例咽旁隙肿块患者中,神经鞘瘤36例、涎腺混合瘤15例、颈动脉体瘤5例、鼻咽癌颅底咽旁隙转移4例。神经鞘瘤表现为包膜完整、边界光滑、呈椭圆形或圆形的肿块,与腮腺深叶间分界清楚,涎腺混合瘤为包膜完整的圆形肿块,与腮腺深叶间没有脂肪间隙,茎突、二腹肌、腭帆张肌等周围组织均出现移位。颈动脉体瘤表现为形态规则的软组织肿块,CT平扫呈等密度、增强后明显强化;MRI扫描,T1W1呈等或稍高于肌肉信号,T2W1呈不均性的高信号,并可见流空血管影像。鼻咽癌颅底咽旁隙转移的MRI显示,T1W1呈低密度信号的椭圆形肿块,增强后高信号内可见坏死囊变区。结论正确地认识咽旁隙肿块的CT及MRI影像学特征,有助于提高其临床诊断率,为咽旁隙肿块的治疗提供一定的依据。     

Lipoma of the deep lobe of the parotid gland: report of 3 cases

Since lipomas are common soft-tissue neoplasms in other regions of the body, they are found only rarely in the parotid gland and are, therefore, often not considered in the initial differential diagnosis of parotid gland tumours. Even rarer are lipomas arising in the deep lobe of the parotid gland with only 6 cases presented in the literature. Lipomas originating in the parapharyngeal space are also extremely rare. When there is any suspicion, computed tomography and especially magnetic resonance imaging are of high diagnostic value. Fine-needle aspiration cytology seems not to contribute much to an accurate diagnosis. None of these preoperative examinations allows an absolute reliable distinction between a lipoma and a liposarcoma. The preferred treatment is complete surgical excision which will minimize the possibility of a recurrence and will also lead to a definitive diagnosis. We report 3 patients with a lipoma of the deep lobe of the parotid gland, extending into the parapharyngeal space, and discuss differential diagnosis and radiological features of lipomas in this rare location.     

Management of lipomas arising from deep lobe of the parotid gland

OBJECTIVES: We would like to present our experience in management of lipomas arising in the deep lobe of the parotid gland, which were diagnosed and operated in our clinic from the point of complication/morbidity, and recurrence, in line with the literature. MATERIAL AND METHODS: Five patients with lipoma found in the deep lobe of the parotid gland, diagnosed and treated at our clinic in the 12-year period between March 1992 and March 2004, were included in this study. Limits of the tumors were determined by computed tomography (CT), and/or magnetic resonance imaging (MRI). Preoperative fine needle aspiration biopsy (FNAB) was also performed. Through a classic parotidectomy incision, the parotid gland was exposed. Full exposure of the facial nerve and its branches was performed. The removal of deep lobe parotid lipomas was achieved by enucleation in all cases. Postoperative complication/morbidity and recurrence were evaluated. RESULTS: The most common symptom was an otherwise asymptomatic mass on the parotid region and/or upper lateral neck. One of five patients was presented with medial displacement of the lateral pharyngeal wall, and tonsil as the additional physical finding. Preoperative radiologic evaluation results revealed that CT and/or MRI scans accurately localized 100% of the tumors in relation to the deep lobe of the parotid gland. FNAB did not enable us to make a diagnosis of lipoma in four of the cases. Total resection was achieved in all cases. Temporary facial nerve paralysis, due to the dissection of the facial nerve, did not occur in any cases. There was no recurrence of the tumors after a mean follow-up of 60 months. CONCLUSION: Assessment of the exact location of the tumor is an important consideration for selection of the appropriate surgical approach. Different from lipomas found in other locations, those observed in the parotid gland cannot be easily resected by simple dissection. Resection of these tumors requires full exposure of the facial nerve.     

Tonsillendifferenz bei infraaurikul?rer Raumforderung

We report on a very rare case of iceberg tumor. A giant lipoma arising from the deep lobe of the parotid gland led to an infraauricular mass and tonsil protrusion. After appropriate imaging (ultrasound and MRI) surgical resection was performed. Tonsil protrusions require differential diagnostic evaluation. Apart from the most prevalent parotid gland tumors, like pleomorphic adenoma and cystadenolymphoma, one must consider rare lipomas. Malignancy (e.g. liposarcoma) can only be excluded by histological examination of the whole specimen.     

Thrombosed varicose vein in the sternocleidomastoid muscle

A thrombosed varicose vein arising in the neck is quite rare. A 68-year-old Japanese male was referred to our hospital because of a mass in his left upper neck. The mass did not change in size in response to strain resulting from Valsalva's manouvre. Magnetic resonance imaging (MRI) showed iso-signal intensity of the mass on T1-weighted images and a target-like signal arrangement (concentric hyper-, hypo-, hyper-signal intensity from outside to inside) on T2-weighted images. Surgical excision revealed that the tumour arose from the intramuscular small vein in the sternocleidomastoid muscle. The pathological examination revealed the mass to be a thrombosed varicose vein with capillarization in the dilated vein wall. The de-oxygenation and degradation of haemoglobin were thought to be responsible for these characteristic MRI findings. The concentric signal distribution on MRI strongly suggested this pathology.     

Nuclear magnetic resonance tomography in the diagnosis of parotid tumors. A comparison of methods

The diagnostic value and the limitations of magnetic resonance imaging (MRI) in the management of large parotid masses were evaluated in a prospective clinical study. The results were compared with computed tomography (CT) and B-mode ultrasonography (US). MRI was performed using a Siemens 1.5 Tesla Magnetom with a RF head coil and surface RF coils. The images were evaluated by the following parameters of clinical importance: tumour detectability and marginal appearance, internal architecture, regional extension, and artifact degradation. MR imaging of parotid masses was superior to CT and US for the following reasons. The marginal appearance of the tumour was sharp and further enhanced in T2 weighted pictures. The extension of the tumour can be well seen by use of transaxial and frontal projections. This is an advantage especially when the mass extends to the retromandibular fossa or even to the pterygopalatine fossa. The position of the jaw, external ear canal, mastoid, skull base, and vessels of the neck are clearly shown without artifact degradation. Benign neoplasms can be well differentiated from malignant tumours which show local infiltration into the adjacent anatomical structures as well as irregularities of their internal structure. However, their appearance in MRI can be identical to that of an acute inflammation of the parotid gland. In summary MRI is the imaging technique of choice for extensive parotid masses, whereas US is effective for small tumours not situated in the retromandibular fossa.     

Lipoma of the deep lobe of parotid gland — a case report and review of literature

Lipoma of deep lobe of parotid gland is a rare clinical entity. Less than 10 cases have been reported in the literature in our knowledge. Because of their rarity, they are not often considered in the differential diagnosis of parotid tumors. A case of 45-year-old man with an unusually large deep lobe lipoma of parotid gland is presented in this article which was surgically managed by total conservative parotidectmy. The clinical picture, radiological and histopathological features of this entity is being discussed here. Review of literature of this clinical situation has been presented in the present article.     

The ultrasound examination in assessment of parotid gland tumours: the novel graphic diagram

Ultrasound is one of the main diagnostic techniques for parotid gland tumours. It is inexpensive, non-invasive and widely available. However, interpretation of the images is highly subjective and constitutes a major limitation. To overcome this problem, we developed a graphic diagram to provide a standardised template that can be used for more precise identification of the tumour localisation within the parenchyma of the parotid gland. This new diagram may be used to provide surgeons with an improved and more objective localisation of the tumour. The study included 237 patients who underwent surgery for parotid tumours. To obtain the precise spatial location of the tumours, three topographic coordinates of tumour location in the coronal, sagittal and transversal plane were marked preoperatively during sonography within the parenchyma of the parotid gland. The localisation identified ultrasonically was then compared to the postsurgical report: 197 (83 %) tumours were found within the superficial lobe of the parotid gland and 40 (17 %) within the deep lobe of the parotid gland. In 157 (66 %) cases, tumours were found within the lower pole of the parotid gland, and in 64 (27 %) at the level of earlobe and its insertion, 16 (7 %) tumours were located at the level of the tragus and above it. Based on the results obtained, a graphic diagram of parotid gland tumour locations was developed.     

Well-circumscribed intramuscular lipoma of the sternocleidomastoid muscle

Intramuscular lipomas are unusual benign mesenchymal tumours, which infiltrate the skeletal muscle, and are exceedingly rare in the head and neck region. They commonly infiltrate the skeletal muscle fibres from which they arise and are rarely well circumscribed. We present the only documented case of well-circumscribed intramuscular lipoma arising from the sternocleidomastoid muscle. Although the recurrence is commoner in the infiltrative variety the surgeon should be aware that differentiation between infiltrative and well circumscribed is based on histological diagnosis, and hence wide excision in all cases of intramuscular lipomas is essential.     

Pleomorphic adenoma and severe obstructive sleep apnoea

Two cases of deep lobe parotid tumours extending into the parapharyngeal space and causing obstructive sleep apnoea are described. Post-operatively, marked improvements in nocturnal hypoxic episodes and the symptoms of obstructive sleep apnoea were seen. Although minor salivary gland pleomorphic adenomas have been described as a cause of airway compromise, pleomorphic adenomata arising from the deep lobe of the parotid, causing proven obstructive sleep apnoea, have not previously been documented. The anatomy and common pathologies of the parapharyngeal space are discussed.     

Rhabdomyoma of the base of the tongue

The histopathological and imaging findings of a rhabdomyoma of the base of the tongue were studied. An immunohistochemical examination of the tumour cells showed positive immunostaining for myoglobin, desmin, and striated muscle actin, but negative immunostaining for smooth muscle actin. Electron microscopy showed many glycogen granules and mitochondria in the tumour cells. The T2-weighted and contrast-enhanced magnetic resonance images (MRI) clearly delineated morphological features of this tumour, but T1-weighted MRI and computed tomography (CT) images showed no important features. These findings are typical for an adult extracardiac rhabdomyoma located in the head and neck region, and they will be useful for diagnosis of this tumour.     

Results of the surgical management and histopathological evaluation of 88 parotid gland Warthin’s tumours

With the introduction of parotidectomy after identification of the facial nerve the recurrence rates for benign tumours has declined rapidly. Subsequently, attention was focused on other sequelae of parotid surgery. To reduce the specific surgical morbidity, several modifications of parotidectomy have been implemented. This study compares the results of the different surgical techniques with regard to the histopathological findings and recurrence rate for Warthin’s tumour of the parotid gland. Eighty-eight primary surgical parotid procedures were performed on 85 patients for a Warthin’s tumour. The surgical procedures included 52 ‘partial’ superficial parotidectomies, 22 ‘standard’ superficial parotidectomies, 12 partial superficial/deep lobe parotidectomies, and two ‘selective’ deep lobe parotidectomies. No patient developed a recurrence or experienced permanent facial nerve paresis/paralysis, the median follow-up being 93 months. Histopathological examination revealed a multifocal origin in 23% (20/88) of the surgical specimens. Partial parotidectomy is an effective treatment for Warthin’s tumour. There is no need for extended follow-up.     

Deep lobe parotidectomy: clinical rationale in the management of primary and metastatic cancer

Deep lobe parotidectomy is an important management approach for highgrade primary parotid cancers that metastasize to the deep lobe nodes and for cancers that metastasizes to the deep parotid from a site outside the parotid. This paper reviews the rationale for deep lobe parotidectomy with facial nerve preservation for these parotid cancers. Deep lobe parotid involvement was reviewed in 27 patients. Twelve patients had primary parotid tumors that metastasized to the deep lobe, and 15 had tumors outside the parotid that metastasized to deep parotid nodes. Deep lobe parotidectomy should be considered in patients with a highgrade primary parotid tumor, a cancer that metastasizes to a superficial intraparotid node, or a primary parotid malignancy that metastasizes to a superficial parotid node or a neck node.     

Massive infra-clinic invasion of the facial nerve by a myoepithelial carcinoma of the parotid

We report a new case of myoepithelial carcinoma of the parotid gland in an 8-year-old girl. This is the first case published in a child. The parotid tumour was slightly tender and measured almost 2 cm in diameter. There was no associated facial nerve paralysis despite surgical and histologic evidence of massive facial nerve infiltration. We performed total parotidectomy with resection of the intra-mastoid portion of the facial nerve completed with prophylactic lymph node dissection. Eight months after surgery, MRI revealed a deep-lying recurrence, which required reintervention. There has been no subsequent recurrence 18 months after surgery. Microscopic examination of operative specimens confirmed the diagnosis of parotid myoepithelial carcinoma with fusiform cells. Immunohistochemical markers were positive for cytokeratin, epithelial membrane antigen, smooth muscle actin, S-100 protein, anti-desmine and anti-vimentine. This difficult to diagnose tumour, which was individualised by the World Health Organisation in 1991, is considered a moderate to high-grade malignancy when it develops in a pleomorphic adenoma or appears de novo.     

Temporary facial nerve dysfunction after parotidectomy correlates with tumor location

Objective

To investigate the clinical factors associated with temporary facial nerve dysfunction (TFND) following surgery for benign parotid gland tumors.

Methods

We reviewed the records of 175 patients with benign parotid gland tumors who underwent partial parotidectomy at Yokohama City University Medical Center in Japan. TFND was found in 33 patients (18.9%). We used two hypothetical lines in magnetic resonance imaging (MRI) images to define the tumor location (upper/lower or anterior/posterior) in the parotid gland. We then studied the associations of TFND with the following clinical factors: patient age, tumor size, histopathological diagnosis, and the location of the tumor within the parotid gland (superficial lobe/deep lobe; upper part/lower part; and anterior part/posterior part).

Results

Tumors located in the upper parts, anterior parts or the deep lobes of the parotid gland had statistically higher incidences of TFND compared with tumors located in the lower parts, posterior parts or the superficial lobe (P < 0.001, <0.001, <0.01, respectively). The odds ratio for the risk of TFND was significantly high if tumors were located in the upper parts, the anterior parts or the deep lobes with stepwise multivariate regression analysis. The other factors, including patient's age, tumor size, histopathology of the tumor, and inadequate surgeon's experience, were not apparent risks for TFND.

Conclusions

Parotid gland tumors located in the upper parts, the anterior parts or the deep lobes had a higher risk of TFND. The two hypothetical lines we used were shown to be useful to define the tumor location, eventually the risk of TFND.     

Multiple primary pleomorphic adenomas of the unilateral parotid gland

BACKGROUND: Classical lateral parotidectomy is the standard surgical procedure for the management of lateral lobe parotid pleomorphic adenomas in most clinical centres. Extracapsular dissection and subtotal lateral parotidectomy are alternatively discussed in current literature and preferred by many authors. CASE: We report on a 20-year-old patient with multiple primary pleomorphic adenomas in the unilateral parotid gland, which preoperatively presented as a solitary tumour node. CONCLUSION: Considering this case we focus on the distinctive surgical procedures for the management of parotid pleomorphic adenomas. We work out, why lateral or even total parotidectomy are justified in the treatment of solitary palpable tumours and why we account lateral parotidectomy as the standard surgical procedure for the management of lateral lobe parotid pleomorphic adenomas.     

Metastatic breast carcinoma in the parapharyngeal space

The parapharyngeal space is a complex anatomical area, which can give rise to a variety of both primary and metastatic neoplasms. We present an unusual case of metastatic adenocarcinoma of the breast, masquerading as a deep lobe parotid neoplasm, 15 years after the primary presentation. Metastatic breast carcinoma has been previously reported at other sites in the head and neck but this is the first report of metastases in the parapharyngeal space with an oropharyngeal presentation.     

Surgical procedure for Warthin's tumor in the parotid gland

Warthin's tumor is benign and exclusively involves the parotid gland but may, however, often show multifocal and/or bilateral growth. The aim of this study was to evaluate the surgical procedure for removal of this tumor. Sixty patients with Warthin's tumor in the parotid gland who presented at the Kansai Medical University Hospital from 1990 to 1999 were the subjects of the present study. The surgical procedures were as follows. We performed enucleation for tumors in the deep lobe. Tumors in the superficial lobe were resected with partial parotidectomy, and an enucleative procedure was also performed at the bottom of the tumor where the tumor capsule directly touched the facial nerve. No recurrence was observed in all sixty cases including cases of rupture of the capsule before or during surgery. Therefore, we recommend that enucleation is a useful choice as a surgical procedure for the removal of Warthin's tumor after accurate detection of the tumors using MRI. The overall incidences of temporary and permanent facial nerve palsy were 19.7% and 0%, respectively. The incidence of palsy increased after surgery for multiple tumors or deep lobe tumors. These findings indicate that more careful consideration for preservation of the facial nerve should be given in such cases and that simultaneous surgery for such tumors in the bilateral parotid glands should be avoided to prevent bilateral facial nerve palsy.