Greater superficial petrosal nerve: anatomy and MR findings in perineural tumor spread.

We report a case of perineural spread of adenoid cystic carcinoma along the greater superficial petrosal nerve. The anatomy of this nerve also is reviewed.     

Clinical-radiologic issues in perineural tumor spread of malignant diseases of the extracranial head and neck.

The radiologic and clinical records of 52 patients with radiologically documented perineural tumor were reviewed to assess the spectrum of tumors responsible, the nerves most commonly involved, and the optimal methods for imaging perineural tumor infiltration. Perineural tumor infiltration was most commonly seen with head and neck squamous cell carcinoma, followed by adenoid cystic carcinoma and several others, such as non-Hodgkin lymphoma, malignant schwannoma, minor salivary gland malignancy, and other sarcomas. The second and third divisions of the trigeminal nerve and the facial nerve were most commonly involved with perineural tumor. Both antegrade and retrograde perineural tumor spread were seen, although retrograde spread was significantly more common. Both high-resolution direct coronal computed tomography and magnetic resonance (MR) imaging clearly showed perineural tumor below the skull base. MR imaging best depicted skull base, cisternal, and brain stem perineural tumor infiltration. T1-weighted MR imaging before and after administration of gadopentetate dimeglumine is the study of choice in investigation of perineural tumor.     

Great auricular nerve: anatomy and imaging in a case of perineural tumor spread

We present the imaging and clinical findings of a case of recurrent cutaneous squamous cell carcinoma of the face in which CT and MR imaging revealed perineural tumor spread along the great auricular nerve. The great auricular nerve is a superficial cutaneous branch of the cervical plexus, providing sensory innervation to the skin of the parotid and periauricular region. Our purpose was to familiarize the reader with the anatomy of this nerve and imaging's potential role in the diagnosis of perineural tumor spread along this seldom seen structure.     

Obliteration of fat planes by perineural spread of squamous cell carcinoma along the inferior alveolar nerve.

Squamous cell carcinoma showed perineural spread along the inferior alveolar nerve. Key CT features of this spread were foramen enlargement, resurfacing of tumor, and asymmetry of fat spaces.     

Nasopharyngeal carcinoma: CT evaluation of patterns of tumor spread

In a prospective study using CT as the initial means of radiologic evaluation in 262 patients with proved nasopharyngeal carcinoma, the paranasopharyngeal space was found to be the most commonly involved region (84.4%), both uni- and bilaterally. Unilateral involvement was found in 44.3% of patients (116/262) and bilateral involvement in 40.1% (105/262). The other structures or regions that were involved, in decreasing order of frequency, were the sphenoid sinus (26.7%), nasal fossa (21.8%), and ethmoid sinus (18.3%). Erosion of the base of the skull and intracranial intracranial extension into the middle cranial fossa were common (31.3% and 12.2%, respectively). The primary tumor in the nasopharynx was found to be contiguous with metastatic upper cervical nodes through paranasopharyngeal extension of tumor in 35 patients (13.4%). A qualitative method to assess the degree of paranasopharyngeal extension is proposed. The extent of paranasopharyngeal extension so evaluated was correlated with other attributes of tumor extent (p = .0001), namely, nasal or oropharyngeal extension, which constitutes a T3-level tumor, and erosion of the base of the skull or orbit, which constitutes a T4-level tumor. The extent of paranasopharyngeal extension was also correlated with local control of the tumors (p = .0001). At a median follow-up of 27 months, only three (7.9%) of the 38 patients with no paranasopharyngeal extension had nasopharyngeal relapse, while 12 (11.2%) of the 107 and 17 (34.7%) of the 49 patients with types 1 and 2 paranasopharyngeal extension, respectively, had nasopharyngeal relapse.(ABSTRACT TRUNCATED AT 250 WORDS)     

MR findings of nine cases of palatal tumor.

PURPOSE: To assess the magnetic resonance imaging (MRI) findings of pathologically confirmed palatal tumors. METHODS: Nine cases of palatal tumor were studied. Clinical data, MRI findings, and pathological diagnoses were evaluated. RESULTS: Five cases were tumors of the hard palate and four of the soft palate. Signal intensity on T1-weighted images varied, and hyperintensity was observed on T2-weighted images. Adenoid cystic carcinoma and diffuse large B cell lymphoma showed homogenous signal intensity. Other tumors showed heterogeneous signal intensities. On dynamic contrast analysis, malignant pleomorphic adenoma, adenoid cystic carcinoma, diffuse large B cell lymphoma, and peripheral T cell lymphoma showed early enhancement. On post-contrast T1-weighted images, hard palate pleomorphic adenoma, malignant pleomorphic adenoma, adenoid cystic carcinoma, diffuse large B cell lymphoma, and peripheral T cell lymphoma showed strong enhancement. Although the borders of the tumors were classified as clear in 6 cases treated surgically, macroscopic and microscopic borders of the tumors were unclear. Adenoid cystic carcinoma and hard palate diffuse large B cell lymphoma invaded the maxillary bone. CONCLUSION: Magnetic resonance findings of palatal tumor varied in different histologies. Even with a small palpable portion, malignant tumors could directly infiltrate surrounding structures, which demonstrated well on MRI.     

Leptomeningeal carcinomatosis from perineural invasion of a lip squamous cell carcinoma

Perineural invasion resulting in leptomeningeal carcinomatosis is a rare, but well-recognized phenomenon in head and neck carcinomas. We report the rare case of a patient with a squamous cell carcinoma of the lip resulting in leptomeningeal carcinomatosis and review the relevant published work. A 51-year-old man presented with progressive facial paraesthesia after treatment for a recurrent squamous cell carcinoma of the lower lip. Cavernous sinus involvement was confirmed on MRI and he received stereotactic radiotherapy. He subsequently developed progressive lower limb neurological signs. An MRI showed multiple enhancing leptomeningeal nodules in the cervical and lumbar spine consistent with leptomeningeal carcinomatosis. Whole spine radiotherapy and dexamethasone resulted in short-term stabilization of symptoms only and he rapidly succumbed to progressive neurological disease. To our knowledge, this is the first published report of a squamous cell carcinoma of the lip resulting in leptomeningeal disease of the cauda equina. It illustrates the potential aggressive natural history of squamous cell carcinomas with perineural invasion.     

CT of perineural tumor extension: pterygopalatine fossa

Tumors of the oral cavity and paranasal sinuses can spread along nerves to areas apparently removed from the primary tumor. In tumors of the palate, sinuses, and face, this "perineural" spread usually involves the maxillary division of the trigeminal nerve. The pterygopalatine fossa is a pathway of the maxillary nerve and becomes a key landmark in the detection of neural metastasis by computed tomography (CT). Obliteration of the fat in the fossa suggests pathology. Case material illustrating neural extension is presented and the CT findings are described.     

CT and MR findings in neoplastic perineural spread along the vidian nerve

The aims of this article are to describe the findings of perividian tumor spread and to compare the accuracy of MRI and CT in diagnosing perineural metastasis along the vidian nerve. Moreover, the frequency of perividian metastasis in patients with head and neck cancer was evaluated. The CT and MR examinations of 98 consecutive untreated patients with histologically proven head and neck cancer were retrospectively reviewed. We considered as criteria for perineural tumor spread along the vidian nerve the following CT and MR findings: For CT (a) enlargement of the pterygoid canal, (b) erosion of its bony wall, and (c) obliteration of its normal fatty content; and for MR (a) enlargement of the vidian nerve, (b) enhancement of the nerve, and (c) obliteration of fat, particularly in the anterior part of the pterygoid canal. Ten patients met the selected criteria for perineural metastasis, which was bilateral in 3 patients, with a total of 13 vidian metastases. The CT scans demonstrated unilateral involvement of the vidian nerve in 9 patients. The MRI scans showed 13 perineural metastases. In 3 patients MR scans demonstrated involvement of four vidian nerves that appeared normal on CT examinations. The diagnostic difference between CT and MRI was statistically significant (Fisher's exact test; p = 0.04). Perineural spread along the vidian nerve is an event more frequent than previously reported and must be investigated with a careful imaging technique. Although a major limitation of our study is the lack of histological proof, the MR finding of a significant enhancement of the nerve, whether enlarged or normal in size, could be considered very suggestive of this kind of metastatic spreading, particularly if associated with simultaneous involvement of the neighboring structures (pterygopalatine fossa, foramen lacerum, trigeminal branches, etc.). Received: 5 January 1999; Revision received 11 May 1999; Accepted: 17 June 1999     

肝细胞癌合并胆管癌栓的影像表现

目的 探讨胆管癌栓的影像表现,以提高影像诊断水平.方法 回顾性分析经手术病理证实的肝细胞癌(HCC)胆管癌栓13例患者资料,其中3例进行了CT和MR检查,2例仅行CT检查,8例仅行MR检查,7例进行了MR胰胆管成像检查,13例均进行了超声检查.采用四格表Fisher 确切概率检验方法比较超声与CT、MR诊断HCC胆管癌栓的准确性.结果 13例HCC肿瘤及胆管癌栓均在CT或MRI上显示.4例胆管癌栓在CT上表现为胆管内软组织块影,动脉期可见癌栓轻度增强,癌栓远端胆管扩张.11例胆管癌栓在T1 WI上均呈稍低信号,T2 WI为稍高信号,增强后可见轻、中度强化.MR胰胆管成像上胆管癌栓表现为:胆管阻塞中断、狭窄或不规则充盈缺损伴有梗阻上方胆管扩张,胆管突然截断或呈"鼠尾"状(5例);肝内胆管扩张,癌栓充满整个胆总管.胆总管不显示(2例).超声检查准确诊断胆管癌栓7例,误、漏诊6例.CT、MRI准确诊断12例,误诊4例,超声与CT、MRI诊断胆管癌栓差异无统计学意义(P=0.270).结论 CT或MRI对诊断HCC合并胆管癌栓及明确癌栓范围有价值.     

Periventricular spread of tumor demonstrated by computed tomography.

Spread of intracranial neoplasms through the periventricular tissues of the brain is well known to neuropathologists, but is almost never recognized by the usual neuroradiologic techniques of angiography and pneumoencephalography. Periventricular tumor spread can, however, be readily dmonstrated by contrast-enhanced CT scanning. This report documents 4 cases of periventricular tumor diagnosed by CT scanning.     

Imaging of Merkel cell carcinoma.

Merkel cell carcinoma (MCC) is a rare, highly malignant cutaneous tumor, primarily of the head and neck, that requires timely diagnosis, adequate staging, and aggressive therapy. MCC tends to be overlooked in the early stage, has a high propensity for invading local and regional nodal basins, and exhibits a high postoperative recurrence rate, with distant thoracic, abdominal, and central nervous system metastases. Conventional radiography and cross-sectional imaging show lesions similar to those originating from other small cell carcinomas. Nuclear medicine procedures such as sentinel node scintigraphy, somatostatin receptor scintigraphy, and positron emission tomography may be used to supplement judicious cross-sectional imaging evaluation, thereby adding diagnostic value in staging and providing therapeutic guidance. Ultimately, however, the diagnosis relies exclusively on pathologic findings at immunohistochemical staining and electron microscopy. The rarity of MCC and the resulting insufficient awareness of this neoplasm often delay correct identification and treatment, which essentially consists of wide-margin surgical excision of the primary tumor and local and regional radiation therapy. To date, clinical information is still insufficient to fully appreciate the role of imaging in MCC management. A better imaging algorithm is expected with increased awareness and improved clinical understanding of this uncommon skin neoplasm.     

Orbital apex syndrome due to trigeminal perineural spread of sinonasal leprosy: a case report

Leprosy is a granulomatous disease primarily affecting the skin and peripheral nerves caused by Mycobacterium leprae, but also significantly involving sinonasal cavities and cranial nerves. It continues to be a significant public health problem, and despite multidrug therapy, it can still cause significant morbidity. The awareness of cranial nerve, intracranial and orbital apex involvement as in our case is important for appropriate treatment measures.     

Imaging of abdominal nodal spread in malignant disease

This is a review of the role of imaging procedures for the assessment of abdominal and pelvic lymph nodes. The diagnosis of malignant lymphatic spread is rarely the sole purpose of imaging, because it is usually part of a general abdominal examination, most frequently with CT or US, or increasingly with MRI. These studies are often requested in order to obtain information about the situation to be encountered during surgery, or to alert the surgeon to irresectability or to unexpected metastases outside the initially planned area of exploration. In most surgically treated tumours the role of imaging for preoperative staging is limited, due either to its insufficient sensitivity or because the initial treatment is independent of the lymph node stage. Imaging is commonly used to verify treatment response to chemo- or radiotherapy and for follow-up.Correspondence to: S. Delorme     

Intracranial perineural metastasis of adenoid cystic carcinoma of head and neck

Three cases of intracranial perineural metastasis from adenoid cystic carcinoma of the head and neck are presented. The metastases presented more than 1 year (14 months to 5.5 years) after the primary tumor had been successfully treated without any evidence of local recurrence. Computed tomography of the intracranial metastasis demonstrated well-demarcated, hyperdense, enhancing extraaxial masses indistinguishable from meningioma. An intracranial extraaxial mass lesion with the appearance of a meningioma in a patient with known adenoid cystic carcinoma of the head and neck, regardless of the presence or absence of local recurrence, should be considered as metastasis until proved otherwise.