Hemangioma of the nasal vault: MR and CT features

Six patients with a history of epistaxis (five patients) or nasal obstruction (one patient) were found to have a capillary hemangioma of the nasal vault that involved one or more nasal turbinates. Four patients underwent computed tomographic (CT) examination; two of these also underwent magnetic resonance (MR) imaging. Four others underwent only MR imaging. At CT and MR, all of the lesions were well circumscribed and intensely enhancing, with contralateral deviation of the nasal septum. Remodeling of the surrounding bone was present in three patients. On T1-weighted MR images, the masses were intermediate in signal intensity. Varying degrees of T2 shortening were shown on T2-weighted MR images, with an appearance that suggested the presence of blood products surrounding an inner matrix of higher-signal-intensity tumor. Intense enhancement at CT and MR assisted differentiation of tumor from retained sinonasal secretions. In two patients, external carotid arteriography revealed small foci of pooling contrast material; in one of these patients, arteriovenous shunting was also present. Pathologic examination in all patients demonstrated capillary hemangiomas with varying degrees of fibrosis and hemosiderin deposition.     

The CT findings of acute thyroiditis and acute suppurative thyroiditis

Although acute thyroiditis often has a distinctive clinical presentation, this relatively uncommon entity can occasionally be confused with other inflammatory processes. In general, the earlier the diagnosis of acute thyroiditis is established, the lower is the frequency and severity of its attendant complications. Computed tomography (CT) is an extremely useful modality in establishing the diagnosis early because it can evaluate iodine content of the thyroid gland and provides more accurate mapping than ultrasound and nuclear medicine techniques. Three patients with acute thyroiditis--two with suppuration--are presented and the CT findings and clinical aspects of this disease are reviewed.     

Olfactory Schwann cells are derived from precursor cells in the olfactory epithelium

In this morphological and immunohistochemical study we show that olfactory schwann cells (OSC) are derived from precursor cells residing in the olfactory epithelium. During development, they migrate out of the epithelium and extend processes to ensheath the olfactory axons. Olfactory mucosa from E14 rat embryos and juvenile rats were treated with trypsin-pancreatin to remove the underlying connective tissue. The epithelial explant was then maintained for two days in culture, during which cells migrated out from the explant. Among them were spindly bipolar cells which were identified as OSC by their positive immunoreaction for glial fibrillary acidic protein, ultrastructure, and association with growing axons. Axonal growth was significantly more profuse in the embryonic explants, in which the polarity of the OSC was oriented parallel with the axons. Ultrastructural observations showed that ensheathment of the bundles of axons resembled those in vivo.     

Neural cell adhesion molecules are present in the fetal human primary olfactory pathway.

Olfactory tissues from human fetuses (17.5-28 weeks of gestation) were stained by immunofluorescence for neural cell adhesion molecules (N-CAMs). Staining for N-CAMs was most prominent in the olfactory nerve bundles in the lamina propria, while in the olfactory epithelium, it was present on the olfactory receptor neurons and globose basal cells. The basal cells proper and supporting cells lacked N-CAMs. In the olfactory bulb, only the olfactory nerve and glomerular layers showed moderate labeling for N-CAMs. Western blot analysis showed that the N-CAMs of the fetal human primary olfactory pathway consisted of three molecular isoforms, N-CAM180, N-CAM140 and N-CAM120.     

Inflammatory pseudotumor of the maxillary sinus in a 15-year-old boy.

Inflammatory pseudotumor is a benign neoplasm composed of fibroblasts, histiocytes, and inflammatory cells. Its occurrence in the paranasal sinuses is rare. We report a case of a 15-year-old boy with a maxillary sinus inflammatory pseudotumor that simulated an aggressive neoplasm on CT scan.