Imaging features of meningeal inflammatory myofibroblastic tumor.

BACKGROUND AND PURPOSE: Meningeal inflammatory myofibroblastic tumor (IMT) has been rarely reported, and its prognosis is still unclear. Our purpose was to describe the imaging features of patients with meningeal IMT and their results on follow-up studies. MATERIALS AND METHODS: Twenty-four MR images in 10 consecutive patients with pathologically proved meningeal IMTs were retrospectively evaluated, focusing on the lesion distribution, signal intensity (SI), and contrast-enhancement pattern with a review of the clinical records. RESULTS: Eight patients with intracranial IMT showed localized (n = 4) or diffuse (n = 4) dural thickening, a single mass (n = 5) or 2 (n = 2) dural-based masses with surrounding edema, dural venous sinus thrombosis (n = 5), and leptomeningeal involvement (n = 5). Extracranial involvement of the mastoid (n = 2) and orbit (n = 2) was also associated. Each of the 2 patients with intraspinal IMT showed a dural-based mass and a segmental dural thickening, respectively. All of the thickened dura showed low SI on T2-weighted images, iso-SI on T1-weighted images, and diffuse contrast enhancement. Variable recurrences with dural-based masses, mastoid involvement, or nasolacrimal duct involvement were observed in all 4 patients with diffuse intracranial IMT, but not in the others. CONCLUSIONS: Localized or diffuse dural thickening of T2 low SI and diffuse contrast enhancement combined with dural-based masses are a common MR imaging finding of meningeal intracranial IMT. Adjacent leptomeningeal involvement and dural venous sinus thrombosis are frequently associated. The diffuse type has a tendency toward recurrence.

Sinonasal inverted papilloma: value of convoluted cerebriform pattern on MR imaging.

BACKGROUND AND PURPOSE: A convoluted cerebriform pattern (CCP) has been reported as a valuable MR imaging feature of inverted papilloma (IP). The purpose of this study was to validate the usefulness of CCP for distinguishing IP from various malignant sinonasal tumors in a relatively large number of patients. MATERIALS AND METHODS: We retrospectively reviewed MR images of 30 patients with IP and 128 patients with various malignant sinonasal tumors proved on histologic examination and compared the prevalence of a CCP between the 2 groups. In 8 patients with IP concomitant with squamous cell carcinoma, we also tried to find the MR features to help suggest coexistent malignancy. RESULTS: A CCP was demonstrated in all 30 (100%) of the IPs and 17 (13%) of the 128 malignant sinonasal tumors on MR imaging. There was a significant statistical difference in the prevalence of a CCP between IP and malignant sinonasal tumors with the overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy 100%, 87%, 64%, 100%, and 89%, respectively. Of 8 IPs concomitant with squamous cell carcinoma, a focal loss of a CCP was demonstrated in 4 tumors, 3 of which also showed aggressive bone destruction with extrasinonasal extension on MR images. CONCLUSION: Although a CCP is a reliable MR imaging feature of sinonasal IPs, it can also be seen in various malignant sinonasal tumors. A focal loss of a CCP might be a clue to the diagnosis of IPs concomitant with malignancy.

Sinonasal organized hematoma: CT and MR imaging findings.

BACKGROUND AND PURPOSE: Sinonasal organized hematoma (OH) is an uncommon, nonneoplastic benign condition that can be locally aggressive. The purpose of this work was to characterize the CT and MR imaging findings of sinonasal OH. MATERIALS AND METHODS: CT (n = 11) and MR (n = 10) images of 12 patients (9 men and 3 women; mean age, 41 years; range, 12-76 years) with pathologically proved sinonasal OH were retrospectively reviewed. Particular attention was put on the location, shape, size, extent, internal architecture, and enhancement pattern of the lesion and associated sinus wall change. RESULTS: The lesions were seen as an expansile (n = 9) or nonexpansile (n = 3) mass, ranging in size from 2.2 to 6.0 cm (mean, 4.2 cm), primarily involving the maxillary sinus (n = 11) or nasal cavity (n = 1) unilaterally. The ipsilateral nasal cavity was also involved in 9 of 11 maxillary sinus lesions. Smooth sinus wall erosion other than the medial maxillary sinus wall was noted in 8 lesions. The internal architecture was best displayed on T2-weighted MR images on which all of the lesions were seen as a mixture of marked heterogeneous hypointensity and isointensity, surrounded by a hypointense peripheral rim, reflecting histologic heterogeneity of the lesion composed of hemorrhage, fibrosis, and neovascularization. Marked irregular nodular, papillary, or frondlike enhancement at the areas of neovascularization was also a typical finding seen in all of the lesions. CONCLUSION: An expansile soft tissue mass, smooth sinus wall erosion, marked heterogeneous signal intensity with a hypointense peripheral rim on T2-weighted MR images, and marked irregular nodular, papillary, or frondlike enhancement are characteristic CT and MR imaging findings of sinonasal OH.

Solitary fibrous tumor of the orbit: CT and MR imaging findings.

BACKGROUND AND PURPOSE: Solitary fibrous tumor (SFT) is a rare spindle-cell neoplasm originating from mesenchymal fibroblast-like cells. The purpose of this study was to describe the CT and MR imaging features of SFTs in the orbit. MATERIALS AND METHODS: We retrospectively reviewed CT and MR images in 6 patients (2 men and 4 women), aged 18 to 51 years, with SFT proved on histologic examination located in and around the orbit. All patients underwent CT (including dual-phase CT in 3), and MR imaging was obtained in 3. We evaluated the imaging findings with emphasis on the location, size, margin, internal architecture, and pattern of enhancement of the lesion. RESULTS: All 6 lesions were found as a solitary, well-defined mass, ranging in size from 18 to 30 mm (mean, 24 mm). Three were located in the postseptal orbit, 2 in the lacrimal sac, and 1 on the lower eyelid. Compared with the cerebral cortex, all 3 lesions examined by MR imaging showed homogeneous isointense signal intensity on T1-weighted images and heterogeneous mixed isointense and hyperintense signal intensity on T2-weighted images. On visual inspection, all 6 lesions showed marked homogeneous (n = 4) or heterogeneous (n = 2) enhancement on postcontrast CT and MR images. In 3 patients examined with dual-phase CT, all lesions demonstrated rapid enhancement with early washout of contrast material. CONCLUSION: SFT might be included in the differential diagnosis of soft tissue masses in the orbit, if one sees a markedly enhancing mass showing the similar characteristics to those of the internal carotid artery on postcontrast CT or MR images.

Recurrence of squamous cell carcinoma of the oesophagus after curative surgery: rates and patterns on imaging studies correlated with tumour location and pathological stage.

Many factors have been related to recurrence after resection of squamous cell carcinoma of the oesophagus. These include age, gender, location and local stage of tumours, cell differentiation, lymph node metastasis and vascular involvement. The recurrence rates of squamous cell carcinoma after curative surgery are high (34-79%). Tumour recurrence is categorized as locoregional or distant. Lymph node recurrence and haematogenous metastasis to solid organs (commonly to the lung) are the usual patterns of recurrence. Awareness of recurrence patterns, particularly on imaging studies, is essential for the diagnosis of recurrent tumours on follow-up examinations.

Allelopathic effects ofPinus densiflora on undergrowth of red pine forest.

Correlation between the distributional frequency of undergrowth species of red pine forest and their germination and growth effected by pine extracts and leachates was found. It was made clear by germination and growth tests that pine toxic substances inhibit the germination and growth of low frequency species more than high frequency species in a red pine forest and that these substances are contained in descending concentration in fresh and fallen leaves, roots, pine forest soil, and pine rain. The concentration of pine toxic substances in extracts or leachates was affected by extracting or leaching within a given period of time, requiring a few hours for extracts or a few days for leachates. The amount of dry weight inhibition of the undergrowth treated by pine leachates was expressed as a growth inhibition index (GII) for the comparison of tolerance in various species. GII is a relative value (%) of the test groups against the control and it is an exponential function of the amount of pine toxic substances affecting the dry weight of the undergrowth. The substances were analyzed by paper and gas chromatography. Benzoic acid and 11 phenolic acids were identifed by gas chromatography. Benzoic acid was considered to be a key factor of allelopathy in the red pine forest.