Clinical findings in 111 cases of influenza A (H7N9) virus infection.

BACKGROUND: During the spring of 2013, a novel avian-origin influenza A (H7N9) virus emerged and spread among humans in China. Data were lacking on the clinical characteristics of the infections caused by this virus. METHODS: Using medical charts, we collected data on 111 patients with laboratory-confirmed avian-origin influenza A (H7N9) infection through May 10, 2013. RESULTS: Of the 111 patients we studied, 76.6% were admitted to an intensive care unit (ICU), and 27.0% died. The median age was 61 years, and 42.3% were 65 years of age or older; 31.5% were female. A total of 61.3% of the patients had at least one underlying medical condition. Fever and cough were the most common presenting symptoms. On admission, 108 patients (97.3%) had findings consistent with pneumonia. Bilateral ground-glass opacities and consolidation were the typical radiologic findings. Lymphocytopenia was observed in 88.3% of patients, and thrombocytopenia in 73.0%. Treatment with antiviral drugs was initiated in 108 patients (97.3%) at a median of 7 days after the onset of illness. The median times from the onset of illness and from the initiation of antiviral therapy to a negative viral test result on real-time reverse-transcriptase-polymerase-chain-reaction assay were 11 days (interquartile range, 9 to 16) and 6 days (interquartile range, 4 to 7), respectively. Multivariate analysis revealed that the presence of a coexisting medical condition was the only independent risk factor for the acute respiratory distress syndrome (ARDS) (odds ratio, 3.42; 95% confidence interval, 1.21 to 9.70; P=0.02). CONCLUSIONS: During the evaluation period, the novel H7N9 virus caused severe illness, including pneumonia and ARDS, with high rates of ICU admission and death. (Funded by the National Natural Science Foundation of China and others.).

[CT and MRI findings in patients with autoimmune pancreatitis].

OBJECTIVE: To evaluate computed tomography (CT) and magnetic resonance imaging (MRI) findings in patients with autoimmune pancreatitis (AIP). METHODS: The imaging findings of pancreas and extra-pancreas in 24 patients with AIP were retrospectively reviewed. Among them, CT scan was performed in 18 patients, MRI in 11, and bGth CT and MRI in 10. RESULTS: The pancreas showed diffuse enlargement (25%, 6/24), focal enlargement (37. 5%, 9/24), combined enlargement (25%, 6/24) ,and no enlargement (12. 5%, 9/24). Unenhanced CT showed hypoattenuation in AIP area (n = 2) . After intravenous injection of contrast medium, 17 patients showed abnormal contrast enhancement in the affected pancreatic parenchyma, including hypoattenuation during the arterial phase (50%, 9/18) and hyper attenuation during the delayed phase (94. 4%, 17/18). Precontrast MRI showed abnormal signal intense (n =9), including hypointense on T1-weight images (T1 WI) (n = 7), hyperintense (n = 7) and hypointense (n = 2) on T2-weight images (TIWI). Enhanced MRI demonstrated abnormal contrast enhancement within lesions (n = 11), including hypoattenuation during the arterial phase (81. 8%, 9/11) and good enhancement during the delayed phase (100%, 11111). A capsule-like rim was seen around pancreas (37. 5%, 9/24), among which CT detected in 6 out of 18 patients and MRI found in 7 out of 11 patients.The main pancreatic duct lumen within lesions has no visualization (100%, 24/24) and upstream dilation of the main pancreatic duct (n = 8) , ranging from 2. 2 to 4. 5 mm(mean 3. 1 0. 47 mm) in diameter. Narrowing of the common bile duct was shown in 14 patients. Miscellaneous findings were: infiltration of extrapancreatic vein (n = 9) and artery (n = 1); mild fluid collection around pancreas (n = 2); pseudocysts (n = 3). Fourteen patients also presented one or more of the following extrapancreatic imaging findings: narrowing of the intra-hepatic bile duct or hilar duct (n = 5); thickening of gallbladder wall (n = 5); fibrosis in mesenteric (n = 2), in retroperitoneal (n = 2) and in ligamentum teres hepatis (n = 1); renal involvement (n = 3); peri-pancreatic or para-aortic lymphadenopathy (n = 10); and ulcerative colitis (n = 3). CONCLUSION: AIP display some characteristic CT and MRI imaging features: sausage-like change of the pancreas; capsule-like rims around lesions; delayed contrast enhancement in the affected pancreatic parenchyma; segment or diffuse pancreatic duct stenosis but mild upstream dilation and extrapancreatic organs involvement. CT and MRI findings combining with serological tests and pancreas biopsy can assist physicians to make accurate and timely diagnosis.

The utility of repeated computed tomography to track a foreign body penetrating the esophagus to the level of the thyroid gland.

OBJECTIVE: Foreign body (FB) ingestion is a common problem in otolaryngology. One uncommon complication of FB ingestion is penetration to the level of the thyroid gland. To our knowledge, only 21 such cases have been reported in the literature. Here, we report a case of an esophageal FB penetrating to the level of the right thyroid gland. CASE REPORT: The patient was a 38-year-old woman in whom an esophageal FB penetrated to the level of the right thyroid gland. We traced the path to the thyroid gland using repeated computed tomography (CT) scans and demonstrated the importance of multiplanar reconstruction in locating the FB and formulating a precise surgical plan. CONCLUSIONS: To our knowledge, this is the first report of repeat CT scans being used to demonstrate the migratory route, over time, of a FB penetrating through the esophagus to the level of the thyroid gland. Our results suggest that multiplanar reconstruction may play a key role in the precise diagnosis of a FB at the level of the thyroid gland and may help surgeons choose the best approach for removal.

Poor outcome of comprehensive therapy in a case of laryngeal synovial sarcoma.

BACKGROUND: Synovial sarcoma is common in the extremities. Our search revealed only 17 cases of synovial sarcoma of the larynx in the English-language literature. CASE REPORT: We report an additional case of a 37-year-old man with primary laryngeal synovial sarcoma who underwent positron emission tomography/computed tomography (PET/CT) following the treatment. Although the patient received comprehensive therapy including surgery, radiotherapy, repeated chemotherapies, and targeted therapies, he had an unfavourable outcome and died of distant metastases. CONCLUSIONS: In synovial sarcoma of the larynx, PET/CT can detect recurrence and metastasis. PET/CT can also predict the treatment effect in patients with synovial sarcoma.

[Value of 18F-FDG-PET/CT in diagnosis of classic fever of unknown origin].

OBJECTIVE: To evaluate the application of (18)F-FDG PET/CT in diagnosis of classic fever of unknown origin. METHODS: A total of 27 consecutive patients with classic fever of unknown origin (FUO) (19 men, 8 women; aged 24-82 y) underwent (18)F-FDG PET/CT scans. The images were interpreted by visual inspection and semiquantitative analysis(standardized uptake value, SUV). Final diagnosis was based on histopathology or clinical follow-up. RESULTS: The cause of FUO was confirmed by followed investigations in 21 of 27 cases after PET/CT scan, including 10 cases of infection, 4 of noninfectious inflammation, 4 of malignancies and 3 of miscellaneous disorders; and remaining 6 cases were still confirmed FUO. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 100.0 %, 83.3%, 83.3%, 100.0% and 96.3%, respectively. CONCLUSION: For patients with fever of unknown origin, (18)F-FDG-PET/CT can be a sensitive, reliable imaging modality. It is suggested that (18)F-FDG-PET/CT should be considered earlier in detecting the causes of FUO, which is difficultly diagnosed by conventional modalities.

Excision of tumors in the parapharyngeal space using an endoscopically assisted transoral approach: a case series and literature review.

OBJECTIVE: Magnetic resonance imaging (MRI) provides important information regarding tumors in the parapharyngeal space (PPS), revealing their origin, whether they are benign or malignant, and their relationships with surrounding structures. METHODS: Twelve tumors in the PPS were completely excised using an endoscopically assisted transoral approach (EATA). The MRI features were analyzed. RESULTS: Ten pleomorphic adenomas confirmed on postoperative pathological examination had the parotid pedicle sign. A fat space between the tumor and parotid gland may distinguish such a tumor from a tumor arising from a minor salivary gland in the prestyloid space and a tumor arising from the deep lobe of the parotid gland. Both the jugular vein and carotid artery were displaced posteriorly in all 10 cases of pleomorphic adenomas. The principal features of the two schwannomas confirmed on postoperative pathological examination were separation of the internal carotid artery and internal jugular vein and anteromedial displacement of the internal carotid artery, suggesting that the tumors originated in the poststyloid space. In this review, 95 tumors were excised by the EATA in the English-language literature. CONCLUSIONS: MRI renders differential diagnosis possible. PPS tumors may be completely excised via an EATA guided by tumor features evident on preoperative MRI.

Collision carcinoma of squamous cell carcinoma and small cell neuroendocrine carcinoma of the larynx: A case report and review of the literature.

BACKGROUND: Collision carcinoma is rare in clinical practice, especially in the head and neck region. In this paper, we report a case of squamous cell carcinoma (SCC) and neuroendocrine carcinoma (NEC) colliding in the larynx and review 12 cases of collision carcinoma in the head and neck to further understand collision carcinoma, including its definition, diagnosis, and treatment. CASE SUMMARY: A 61-year-old man presented with a 1-year history of hoarseness. Contrast-enhanced magnetic resonance imaging of the larynx revealed that the right vocal cord had a nodule-like thickening with obvious enhancement. Laryngoscopy revealed a neoplasm on the right vocal cord, and a malignant tumor was initially considered. A frozen section of right vocal cord was performed under general anesthesia. The pathological result showed a malignant tumor in the right vocal cord. The tumor was excised with a CO2 laser (Vc type). Routine postoperative pathology showed moderately differentiated SCC with small cell NEC in the right vocal cord. No metastatic lymph nodes or distant metastases were found on postoperative positron emission tomography/computed tomography. Because of the coexistence of SCC and NEC, the patient received adjuvant chemotherapy and radiotherapy. The patient was followed for 8 mo, and no recurrence or distant metastasis was found. CONCLUSION: The treatment of collision carcinoma in the head and neck region is uncertain due to the small number of cases.

Role of fluorodeoxyglucose-PET versus fluorodeoxyglucose-PET/computed tomography in detection of unknown primary tumor: a meta-analysis of the literature.

The objectives of this study were to evaluate the diagnostic accuracy of fluorodeoxyglucose (FDG)-PET and FDG-PET/computed tomography (CT) in the detection of primary tumors in patients presenting with carcinoma of unknown primary (CUP) unidentified by conventional workup, and to compare the statistical difference between the FDG-PET and FDG-PET/CT. Twenty-eight studies (involving a total of 910 patients) published between 1990 and 2007 were reviewed. These studies evaluated the role of FDG-PET and FDG-PET/CT in the detection of unknown primary tumors after physical examination and conventional workup failed to detect a primary tumor. Systematic methods were used to identify, select, and evaluate the methodological quality of the studies as well as to summarize the overall findings of sensitivity, specificity, and detection capacity of the primary tumor. The overall sensitivity and specificity of FDG-PET in detecting unknown primary tumors were 0.78 [95% confidence interval (CI): 0.72-0.84)] and 0.79 (95% CI: 0.74-0.83), respectively. Furthermore, FDG-PET detected 28.54% of tumors that were not apparent after CUP failed to be detected by conventional workup. Data were collected on the locations of primary tumors detected by FDG-PET in 17 studies and detected by FDG-PET/CT in seven studies. Tumors from the base of the tongue accounted for 20.7% (six of 29) of all false-positive FDG-PET scans, corresponding to a false-positive rate of 28.6% (six of 29), much higher than tumors from the others. FDG-PET exhibited a lower sensitivity with respect to the tumors at the base of the tongue and tonsils, which was 68.2 and 76.7%, respectively. In the eight studies with 430 patients diagnosed with CUP by FDG-PET/CT, 31.4% (n=135) of primary tumors were detected. The pooled sensitivity and specificity were 0.81 (95% CI: 0.74-0.87) and 0.83 (95% CI: 0.78-0.87), respectively. FDG-PET and FDG-PET/CT can detect primary tumors that went undetected by physical examination and conventional workup. FDG-PET exhibited lower sensitivity with respect to the tumors at the base of the tongue and the tonsils.

Palatine tonsil schwannoma: correlation between clinicopathology and computed tomography features.

We describe the case of a 37-year old male who presented with a schwannoma in his right palatine tonsil. The tumour and tonsil were surgically removed transorally. Tonsillar schwannomas are slow growing, and the main symptoms were a foreign body feeling in the throat, dysphagia and snoring. The presence of a round, well-defined mass lesion with heterogeneous density on computed tomography (CT) may aid in differentiation from other tonsillar tumours. The CT findings in the reported case were different to those of schwannomas in other locations; the particular CT manifestations of tonsillar schwannomas seem to relate to the various pathological changes seen within the tumour.

The diagnostic role of diffusion-weighted magnetic resonance imaging in hypopharyngeal carcinoma.

The aim of the present study was to assess the role of diffusion-weighted magnetic resonance imaging (DWI) and apparent diffusion coefficient (ADC) values in hypopharyngeal carcinoma. A total of 40 hypopharyngeal carcinoma tissues and 15 benign lesion tissues were retrospectively analyzed. DWI, and T1- and T2-weighted magnetic resonance imaging (MRI) was performed. The sensitivity, specificity and accuracy of conventional MRI were 97.5, 66.7, and 89.1%, respectively. The mean ADC value [diffusion sensitive factor (b)=1,000× sec/mm2) for hypopharyngeal carcinomas was (1.0285±0.0328)×10-3 mm2/sec, which was significantly lower than the mean ADC value for benign lesions [(1.5333±0.1061)×10-3 mm2/sec; P<0.001]. Receiver operating characteristic (ROC) curve analysis revealed that the area under the curve (AUC) was 0.921 while the optimal threshold for the cut-off point of the ADC was 1.075×10-3 mm2/sec. The mean ADC value of the metastatic nodes was (0.9184±0.0538)×10-3 mm2/sec, lower than the mean value for the benign nodes [(1.2538±0.1145)×10-3 mm2/sec; P=0.005]. Two groups were created according to the mean of the ADC value of hypopharyngeal carcinomas [≤(1.0285±0.0328)×10-3 mm2/sec vs. >(1.0285±0.0328)×10-3 mm2/sec]. The 2-year survival rates of the two groups were 55.6 and 100.0%, respectively (P=0.024). ADC values may aid in distinguishing hypopharyngeal carcinomas from benign lesions and differentiating metastatic lymph nodes of hypopharyngeal squamous cell carcinomas from reactive cervical lymph nodes. In conclusion, mean ADC values may be useful prognostic factors in univariate analysis of hypopharyngeal carcinoma.

[Study of paroxysmal kinesigenic dyskinesia with fMRI].

OBJECTIVE: To detect the differences in subcortical structures between patients with paroxysmal kinesigenic dyskinesia (PKD) and normal subjects during movement preparation and execution. METHODS: The PKD patients performed a movement task, in which a CUE signal (preparation) indicated the movement sequence prior to the appearance of an imperative GO signal (execution). Event-related functional magnetic resonance imaging (fMRI) and 3dDeconvolve program of AFNI were used to estimate the hemodynamic response function and to generate activation maps. RESULT: During movement preparation, the activated brain areas in PKD patients were less than those of normal subject, and there was no activation in basal ganglia in PKD patients. During execution, the activation was also less in PKD patients except in bilateral M1. CONCLUSION: During intermission, abnormalities of the brain still exist in PKD patients when during preparing or performing movement. The movement circuit in the brain displays an unusual state. The attack may be caused by reducing of inhibition in brain areas.

Rapid progression of glioblastoma multiforme: A case report.

Glioblastoma multiforme (GBM) tumors are intracranial lesions with varying shapes that grow rapidly. GBM tumors most commonly present as solitary lesions and multiple lesions are rare. The aim of the present case report was to investigate the imaging features of glioblastoma multiforme (GBM). In this study, the case of a 60-year-old patient who was hospitalized due to seizures is presented. Magnetic resonance imaging (MRI) revealed multiple lesions, heterogeneous in size, with peritumoral edema and ring-shaped enhancement. The lesions grew rapidly within 10 days of hospitalization and were initially misdiagnosed as either infections or intracranial metastatic tumors as a result of imaging examinations. The patient was subsequently administered mannitol, diazepam, Tegretol and ceftriaxone. After treatment, the patient recovered and regained full consciousness. However, MRI examination 23 days after hospitalization revealed that the multiple lesions in the left temporal and left occipital lobes had increased in size. Therefore, resection of the tumor in the left temporal occipital lobe was performed. Histopathological examination identified GBM (grade IV) in the left temporal and parietal lobes. The patient succumbed to the disease 7 months after surgery due to GBM recurrence. The findings of the present case indicate that GBM may progress rapidly with a doubling time of 10 days and multiple cystic alterations. Furthermore, if diagnosis of GBM is unclear, early biopsy is recommended.

Evaluation of selective hepatic angiography and embolization in patients with massive hemobilia.

BACKGROUND: Massive hemobilia is a rare but potentially life-threatening cause of upper gastrointestinal hemorrhage. Transarterial embolization is considered the first line of intervention to stop the bleeding for most causes of hemobilia. This study was conducted to evaluate selective hepatic angiography and embolization in the diagnosis and treatment of patients with massive hemobilia. METHODS: The clinical data of 16 patients with massive hemobilia were analyzed retrospectively. These patients underwent emergency celiac and selective right or left hepatic artery angiography and treated by embolization using Gelfoam particles and/or coils. RESULTS: Hepatic artery angiography revealed hepatic artery pseudoaneurysms in 6 patients, cystic artery pseudoaneurysms in 2, diffuse hemorrhage of hepatic artery branches in 5, and right hepatic artery-bile duct fistulae in 3. The patients were diagnosed rapidly by angiography and treated successfully by embolization of the hepatic artery branch proximal to the bleeding point, and hemorrhage was stopped immediately. Two patients were embolized the second time for rebleeding. Neither recurrence of bleeding nor serious complication was found during the follow-up for 3 months to 2 years. The other 2 patients whose hemorrhage failed to be controlled died several days later. CONCLUSION: Being safe, reliable and minimally invasive, selective hepatic artery angiography and embolization are effective in the diagnosis and treatment of massive hemobilia.

[Clinical value of three-dimensional dynamic contrast-enhanced MR angiography in diagnosis of angiostenosis after liver transplantation].

OBJECTIVE: To evaluate the clinical application of three-dimensional dynamic contrast-enhanced MR angiography (3D DCE MRA) in diagnosis of angiostenosis after liver transplantation. METHODS: Twenty recipients of liver transplantation underwent 3D DCE MRA examination. The blood vessel rating grades were accessed and the relative diameter of vascular anastomosis was measured; and the results were compared with those of US or DSA examination. RESULTS: Satisfactory angiography images were obtained in all cases by 3D DCE MRA, including 11 cases with normal and mild stenosis, 5 with moderate and 4 with severe stenosis in hepatic artery. Except one case in which 3D DCE MRA showed severe stenosis but DSA showed moderate stenosis, the results of MRA were all consistent with those of US or/and DSA in the stenosis degree of the portal vein, hepatic vein and the postcava. CONCLUSION: 3D DCE MRA is an effective technique to evaluate the degree of angiostenosis after liver transplantation.

MRS study on lentiform nucleus in idiopathic Parkinson's disease with unilateral symptoms.

OBJECTIVE: To investigate changes in magnetic resonance spectroscopy (MRS) of lentiform nucleus during the early stage of Parkinson's disease. METHODS: Twenty-five patients with idiopathic Parkinson disease with unilateral symptoms (IPDUS) and 25 healthy volunteers were enrolled in this study. MRS of the lentiform nucleus in each patient was taken and then concentrations of N-acetylaspartate (NAA), Creatine (Cr) and Choline (Cho) were calculated. RESULTS: Compared to that in the control, NAA/ (Cho+Cr) was significantly lower in the lentiform nucleus contralateral to symptoms and even that in the ipsilateral side in IPDUS patients (all P<0.05); while there was no difference between the two sides in the healthy volunteer (P>0.05). The ratio of NAA/(Cho+Cr) ipsilateral to the sympatomatic side of the patient was also lower than that of the control (P<0.05). CONCLUSIONS: There might be some changes with MRS on the lentiform nucleus during the early stage of idiopathic Parkinson's disease with unilateral symptom. MRS may be one of the reliable methods for early or even sub-clinical diagnosis.

Differentiating laryngeal carcinomas from precursor lesions by diffusion-weighted magnetic resonance imaging at 3.0 T: a preliminary study.

BACKGROUND: Diffusion-weighted magnetic resonance imaging (DWI) has been introduced in head and neck cancers. Due to limitations in the performance of laryngeal DWI, including the complex anatomical structure of the larynx leading to susceptibility effects, the value of DWI in differentiating benign from malignant laryngeal lesions has largely been ignored. We assessed whether a threshold for the apparent diffusion coefficient (ADC) was useful in differentiating preoperative laryngeal carcinomas from precursor lesions by turbo spin-echo (TSE) DWI and 3.0-T magnetic resonance. METHODS: We evaluated DWI and the ADC value in 33 pathologically proven laryngeal carcinomas and 17 precancerous lesions. RESULTS: The sensitivity, specificity, and accuracy were 81.8%, 64.7%, 76.0% by laryngostroboscopy, respectively. The sensitivity, specificity, and accuracy of conventional magnetic resonance imaging were 90.9%, 76.5%, 86.0%, respectively. Qualitative DWI analysis produced sensitivity, specificity, and accuracy values of 100.0, 88.2, and 96.0%, respectively. The ADC values were lower for patients with laryngeal carcinoma (mean 1.195±0.32×10(-3) mm(2)/s) versus those with laryngeal precancerous lesions (mean 1.780±0.32×10(-3) mm(2)/s; P<0.001). ROC analysis showed that the area under the curve was 0.956 and the optimum threshold for the ADC was 1.455×10(-3) mm(2)/s, resulting in a sensitivity of 94.1%, a specificity of 90.9%, and an accuracy of 92.9%. CONCLUSIONS: Despite some limitations, including the small number of laryngeal carcinomas included, DWI may detect changes in tumor size and shape before they are visible by laryngostroboscopy. The ADC values were lower for patients with laryngeal carcinoma than for those with laryngeal precancerous lesions. The proposed cutoff for the ADC may help distinguish laryngeal carcinomas from laryngeal precancerous lesions.

Correlation of computed tomography with pathological features in angiomatous nasal polyps.

BACKGROUND: Angiomatous nasal polyps (ANPs), also known as angiectatic polyps, have rarely been reported in the literature. ANPs are characterized by extensive vascular proliferation and ectasia. ANPs can grow rapidly and exhibit aggressive clinical behavior that could simulate malignancy preoperatively, and they are easily confused with other diseases. In the present study, we analyzed the correlation between the computed tomography (CT) findings of nasal angiomatous polyps and their pathological features. METHODS: We evaluated CT findings and pathological features of 31 surgically proven ANPs. RESULTS: The study population included 16 males and 15 females aged between 27 and 81 years (mean age, 53.5 years). On CT, the masses were heterogeneous; they had a soft tissue density and filled the maxillary and/or nasal cavities. Calcifications were found in 2 of the 31 cases. The lesions showed a clear boundary (15/31). The low-density shading on CT was related to the inflammatory, necrotic, and cystic changes, and the high-density shading on CT was related to hemorrhagic areas of the mass. On contrast-enhanced CT, the center of the lesions was non-enhanced with peripheral intensification due to occlusion or compression of feeder vessels of the polyp center, and the inflammatory cells and neovascularization around the edge of the mass. The most common site of maxillary wall erosion was the medial wall (21/31), followed by the posterior lateral wall (3/31), upper wall (2/31), and septum (3/31). Of these, the nasal cavity and/or maxillary sinus were enlarged in 28 cases. These findings were associated with the chronic progress of nasal angiomatous changes. CONCLUSIONS: CT of ANPs may demonstrate benign bone changes associated with the lesions and may also reflect the fact that ANPs do not invade peripheral soft tissue. CT demonstrated these lesions consistently and provided information useful for surgical planning.

Etiology analysis and computed tomography imaging of a tonsillar inflammatory myofibroblastic tumor: report of an immunocompetent patient and brief review.

OBJECTIVES: The etiology of Inflammatory myofibroblastic tumor(IMT) is contentious. In this study, we used computed tomography (CT) to examine tonsillar IMT and further analyzed the etiology of this entity. METHODOLOGY: We presented CT features of left tonsillar IMT and reviewed the English-language literature published between 1984 and 2011. RESULTS: To our knowledge, there are only six published cases of tonsillar IMT including the present case. Two patients were asymptomatic at initial presentation. Two patients were taking immunosuppressants, and one was pregnant and in an immunomodulated state. CT of our patient revealed a 2.6 × 1.8 cm irregular soft tissue mass between the left tonsil and the base of the tongue. It did not invade surrounding structures and was not enhanced on contrast-enhanced imaging. CONCLUSIONS: Tonsillar IMT may be a benign tumor. We suggest that preoperative recognition of tonsillar IMT by CT may be important to avoid unnecessary expanded surgery.

Computed tomography and pathological findings of five nasal neurilemmomas.

OBJECTIVES: Neurilemmomas are benign tumors deriving from Schwann cells of the nerve sheath. They occur in all parts of the body. The highest incidence of neurilemmoma is in the head and neck region (38-45%), but involvement of the nose and paranasal sinus is quite rare, with only sporadic cases having been reported in the world literature. Fewer than 4% of these tumors involve the nasal cavity and paranasal sinuses. We describe the clinical, pathologic, and computed tomography (CT) features of five nasal neurilemmomas. METHODOLOGY: CT features of five patients with nasal schwannoma proved by operation and pathology were investigated. RESULTS: Schwannomas tend to be solitary and are usually well-circumscribed tumors with an oval, round or fusiform shape in the unilateral nasal cavity. The lesions usually have a mottled central lucency with peripheral intensification on contrast-enhanced CT scans. The heterogeneous appearance is related to areas of increased vascularity with adjacent non-enhancing cystic or necrotic regions. CONCLUSIONS: Schwannoma should be considered in the differential of unusual nasal masses. Certain clinical and CT patterns may be of use in the differential diagnosis.