The magnetic resonance characteristics of sinonasal rhabdomyosarcoma in adults: analysis of 27 cases and comparison with pathological subtypes.

BACKGROUND: Sinonasal rhabdomyosarcoma (RMS) in adults is extremely rare, and early diagnosis and treatment are crucial to improve the patient's prognosis. The purpose of this study was to evaluate the magnetic resonance imaging (MRI) findings of sinonasal RMS in adults and analyze the correlations between the imaging features and pathological subtypes. METHODS: We reviewed 27 patients with pathologically proven RMS of the nasal cavity and paranasal sinuses, including embryonal RMS (ERMS) in 14 patients, alveolar RMS (ARMS) in seven patients, and mixed-type RMS in six patients. Conventional MRI was performed in all 27 patients, and high-resolution diffusion-weighted imaging was conducted in 25 patients. The tumor location, size, morphological features, signal intensity, texture, contrast enhancement characteristics, lymph node metastases, apparent diffusion coefficients (ADCs), and involvement of local soft tissues were independently assessed by two authors. RESULTS: On MR imaging, sinonasal RMS appeared isointense on T1-weighted imaging in 21 cases (77.8%) and heterogeneously hyperintense on T2-weighted imaging in 18 patients (66.7%). After enhancement, the tumors were heterogeneously enhanced in 24 cases (88.9%). Botryoid enhancement with multiple small rings resembling bunches of grapes was found in 15 cases (55.6%). Mucosal invasion of the maxillary sinus was identified in 51.9% patients. Skull and orbit involvement were found in 55.6% and 81.5% patients, respectively. Lymph node metastasis was seen in 18 cases (66.7%). There were significant differences in botryoid enhancement (P = 0.044) and skull involvement (P = 0.044) among different histological subtypes. The mean ADC value of RMS was 0.73 ± 0.082 × 10-3 mm2/s, and there was no significant difference among different histological subtypes. CONCLUSIONS: Some characteristic MRI findings such as botryoid enhancement in the ethmoid sinus, involvement of the orbit and skull, and a lower ADC value can provide important clues for preoperative diagnosis of sinonasal RMS in adults. Further, botryoid enhancement was more common in ERMS, while skull involvement was more common in ARMS.

Middle Ear Teratoma: Clinical and Imaging Features.

BACKGROUND: Teratoma is a true neoplasm composed of a number of different types of tissue derived from the three germinal layers but rarely occurs in the middle ear (ME). The features of middle ear teratomas (MET) have not been well described. OBJECTIVE: The objective of this study is to explore the clinical and imaging features of MET, and report 2 rare cases of MET with ear malformation that have never been reported. MATERIALS AND METHODS: The clinical, CT and MRI data of 8 patients with a pathological diagnosis of MET were collected and retrospectively mined, and 14 patients with MET reported in previous literature were also reviewed. RESULTS: ① Female, left ear predominance in MET, and the most common symptoms were otorrhea and hearing loss. ② On CT and MRI, the MET presented as an irregular soft tissue mass that was heterogeneous, with fatty tissue and involved multiple sites, and the ET and tympanum were correspondingly expanded and locally destroyed. ③ Mictotia with MET in two patients was presented, which was the first report. CONCLUSION: MET has female sex and left ear predominance. CT and MRI can be used to diagnose MET and display its extent and its relationship to the carotid canal in detail. Complete surgical excision is the definitive treatment.

Role of magnetic resonance diffusion-weighted imaging in differentiating lacrimal masses.

PURPOSE: To evaluate the role of magnetic resonance (MR) diffusion-weighted imaging (DWI) in discriminating lacrimal masses, including neoplastic and nonneoplastic entities. MATERIALS AND METHODS: Forty-four patients with lacrimal masses underwent conventional MRI and DWI. The apparent diffusion coefficient (ADC) values of each mass and the ipsilateral temporal lobe were measured and the ratios of the lesion to temporal lobe ADC were calculated. RESULTS: Pleomorphic adenomas had significantly higher ADC values (1.37 ± 0.22 × 10(-3) mm(2) /sec) and ADC ratios (1.85 ± 0.34) than malignant tumors (1.03 ± 0.19 × 10(-3) mm(2) /sec, 1.37 ± 0.27) (P < 0.001), inflammatory pseudotumors (0.9 ± 0.08 × 10(-3) mm(2) /sec, 1.19 ± 0.07) (P < 0.01), reactive lymphoid hyperplasias (RLHs) (0.6 ± 0.06 × 10(-3) mm(2) /sec, 0.79 ± 0.07) (P < 0.001), and lymphomas (0.55 ± 0.06 × 10(-3) mm(2) /sec, 0.74 ± 0.08) (P < 0.001). RLHs and lymphomas had significantly lower ADC values and ADC ratios than malignant tumors (P < 0.05) and inflammatory pseudotumors (P < 0.05). An ADC value of less than 1.14 × 10(-3) mm(2) /sec and an ADC ratio of less than 1.6 were optimal for differentiating malignant tumors from benign tumors (sensitivity: 80 and 90%, specificity: 100 and 88.9%, respectively). An ADC value of less than 0.76 × 10(-3) mm(2) /sec and an ADC ratio of less than 1.0 were optimal for distinguishing lymphoproliferative disorders from inflammatory pseudotumors (sensitivity: 100%, specificity: 100% for both). CONCLUSION: DWI can help differentiate lacrimal masses and provides a potential clinical tool for noninvasive tissue characterization.

[Imaging diagnosis of masses in temporal bone associated with pulsatile tinnitus].

OBJECTIVE: To improve the imaging diagnosis accuracy on masses of temporal bone associated with pulsatile tinnitus. METHODS: The CT and MRI features of masses in temporal bone associated with pulsatile tinnitus in 32 cases, confirmed by pathology, were retrospectively analyzed. RESULTS: They were grouped into two according to the jugular bulb involved or not. In the group involving the jugular bulb, there were 5 cases with glomus jugular, 2 cases of them presented the feature of "salt-pepper". There were 5 cases with middle ear carcinoma, which presented the masses in the tympanic cavity and antrum, extended to the external auditory canal and eroded the eustachian tube and jugular bulb. There were 3 cases with endolymphatic sac tumors, which presented multiple bony spicules on CT images and high signal on T1-weighted images. There was 1 case with metastatic tumor, which extensively eroded temporal and occipital bone, involved the jugular bulb, presented intermediate signal on T1-weighted images and intermediate or high signal on T2-weighted images, moderately enhanced following contrast administration. In the group not involving the jugular bulb, there were 15 cases with tympanic glomus, without ossicles and tympanic erosion, 7 cases of them limited to the promontory, 7 cases of them filled the tympanic cavity and antrum and 5 cases extended deep into the external auditory canals, 1 case extended to the mastoid, 12 cases intensely enhanced with gadolinium. There were 2 cases with cholesterol granulomas of the middle ear, which presented the masses in the tympanic cavity and antrum and high T1-weighted and T2-weighted signal. There was 1 case with facial nerve hemangioma, which presented the enlargement and mass of the geniculate fossa involving the tympanic segment of facial nerve with the erosion and displacement of ossicles. On MR images, the mass was intensely enhanced after contrast administration. CONCLUSION: Among the masses of temporal bone associated with pulsatile tinnitus, the paragangliomas are the most common and easy to be diagnosed by their imaging features. While the other masses of temporal bone are uncommon, they could also be diagnosed accurately by clinical and imaging characteristics.

Labyrinthine sequestrum: four case studies.

Labyrinthine sequestrum, a rare form of labyrinthitis, is highly distinct from the more commonly encountered labyrinthitis ossificans based on its unique clinical, radiologic, and histologic characteristics. The study included 4 such patients who had undergone clinical and laboratory investigations, computed tomography (CT), and magnetic resonance imaging (MRI) assessments followed by surgical procedures and pathological evaluation. Their major symptoms were otorrhea, otalgia, tinnitus, and profound hearing loss. Imaging studies showed an osteolytic soft mass with calcified debris in the inner ear, and the bony labyrinth was eroded partly or completely by granulation mass, with loss of bony morphology. Further pathological examination was coincident with inflammatory granulation tissue with some calcification or osseous tissue. The disease process is attributed to chronic osteomyelitis due to the presence of osteonecrosis. Prompt CT and MRI examinations and optimal therapeutic management facilitate definitive diagnosis and protect against fatal complications.

3D image of the middle ear ossicles: three protocols of post-processing based on multislice computed tomography.

The aim of this study was to examine and assess the comparative values of HRCT-based multiplanar reformation (MPR), volume rendering (VR) and virtual endoscope built on three-dimensional shaded-surface display (SSD-based CTVE) for evaluations of the ossicular chain. The normal pure tone audiograms, type-A tympanogram, and normal HRCT characteristics of 32 human ears of 18 patients were reviewed, whose ossicular chains were reconstructed with the three aforementioned protocols and assessed via the 3-point scoring system. The HRCT-based protocols could demonstrate a 3D image of the ossicular chain, except that of the footplate on the SSD-based CTVE. On the qualitative assessment, the efficacy of the MPR and VR, which were both superior to the SSD-based CTVE (P < 0.05), presented no statistical significance among the major and/or hyperdense structures (P > 0.05). As regards the lateral process of the malleus, VR was found to be significantly superior to the MPR and SSD-based CTVE (P < 0.05), both of which, however, showed no significant comparative differences (P > 0.05). Moreover, the three protocols in terms of efficacy were comparatively different in their representations of the anterior crus and footplates of the stapes, respectively (P < 0.05). On the MPR images, not all the images of the lenticular process were ideal; 20 of 32 cases were detected, but not defined. VR could be the more valuable protocol for the 3D reconstruction of the ossicular chain and ought to be more employed in future, especially for the education.