Search

Objective: To delineate a possible role of protective function by Ostmann's fatty tissue (OF) in the lateral region to Eustachian tube (ET)., Study Design: Morphometric and histopathological examination on human temporal bones., Methods: OF in the region lateral to the cartilaginous portion of the ET between the ET lumen and the tensor veli palatini muscle (TVP) was studied histopathologically and morphometrically by analyzing a series of vertically cut histologic sections for the ET structures. Sections were obtained from 25 individuals with age ranging from 33 gestational weeks to 38 years at the time of their death., Results: In fetus and neonates, the region lateral to ET was filled with mesenchyme. OF appeared first in this region at 2-3 weeks postnatally, and increased in volume with development of the ET. In the cases of older children and adults (Group-B), the ratio of the volume of OF in the region to that of ET lumen (OF/L) was significantly higher in the posterior half than in the anterior half of the cartilaginous portion of ET. However, in the cases of infants and younger children (Group-A), there was no significant difference in the ratio between the two regions. In the posterior half of the cartilaginous portion of ET, OF/L was significantly higher in Group-B than in Group-A, while in the anterior half, there was no significant difference in the ratio between two age groups (Group-A and B)., Conclusions: In Group-B, the dominant OF in the area of the posterior half of the cartilaginous region, which includes the narrowest portion of ET, may be responsible for restoring the ET lumen back to its closed static condition after active tubal opening by contraction of TVP. This is thought to be important for protection of the middle ear. On the other hand, in Group-A, poor OF near the narrowest portion of ET may cause insufficient restoration of the ET lumen and increased risk of developing otitis media (OM).

In order to delineate the possible role of connective tissue (CT) in the region lateral to the eustachian tube (ET) between the ET lumen and the tensor veli palatini muscle (TVPM), we studied the postnatal changes in the CT in histologic sections of human ET. In fetuses and neonates, the lateral region was filled with mesenchyme. Loose collagenous CT appeared first at 2 weeks of age, and in subjects older than 4 years of age, the collagen formed dense, meshlike structures attaching to both the subepithelial CT layer of the ET and the tendonlike membrane of the TVPM. Along the long axis of the ET, those attachments were distributed mainly in the region at the posterior part of the cartilaginous portion of the ET. Attachments to the subepithelial CT layer of the ET were distributed mainly in the upper half of the region. The dense, meshlike collagenous CT might help the ET to be opened by drawing the lateral wall of the ET lumen through inferolateral movement of the tendonlike membrane of the TVPM when the TVPM contracts. It may work to open mainly the parts that include the narrowest portion of the ET, and also the upper aspect of the ET lumen. Incomplete development of this structure in infants may be one of the factors associated with dysfunction in ET opening.

Objective: To delineate a possible difference in the function of the eustachian tube (ET) between infants and adults., Study Design: Morphometric and histopathological examination on the human temporal bones., Methods: The secretory glands in the ET were studied in serial histological sections through the cartilaginous portion of the human ET obtained from 32 individuals whose ages ranged from 1 day to 19 years. Of these, 26 were normal control cases and 6 were cases with otitis media (OM)., Results: In both normal and OM groups, the distribution of the glands was predominantly in the medial side of the cartilaginous portion of the ET, and the volume of the ET glands was directly related to both the volume of the ET lumen and the patients' age. In normal cases, the relative proportion of the three types of acinar cells (mucous, serous, and mixed) varied among the different age groups. The cases in patients under 1 month of age had more mucous glands and fewer serous glands. In cases of the 1-month-old to 7-year-old age group, the three ET gland cell types came to be approximately equal. Relative proportion of the serous glands continuously increased with aging, and in cases of patients older than 7 years of age, serous glands were predominant over the other two components., Conclusion: It is assumed that the greater proportion of mucous glands and insufficient serous glands by 7 years of age reflects immature development, which may be one of the associated factors contributing to recurrent OM among infants.

This study characterized phenotypic anomalies of the eustachian tube (ET) and its associated structures in individuals with various chromosomal aberrations (trisomies 13, 18, 21, and 22 and inversion of chromosome 1). The morphological characteristics of the ET and its accessory structures from 10 temporal bone-ET specimens, obtained from 10 individuals with chromosomal aberrations who ranged from the 26th gestational week to 1 year in age, were compared with the same structures from 21 age-matched control subjects without anomalies. The subjects with chromosomal aberrations had a significantly smaller volume of the lateral lamina (LL) of the ET cartilage, a reduced attachment of the tensor veli palatini muscle (TVPM), and, in some cases, a reduced volume of the lumen of the cartilaginous ET. The volume of the medial lamina (ML) of the ET cartilage was normal at birth, but smaller in specimens more than 2 months of age; this finding suggests that the prenatal development was normal, but that the postnatal growth was retarded. The subjects with chromosomal aberrations also displayed a smaller ratio of the volume of the LL to that of the ML (LL/ML ratio). Our results suggest that individuals with various chromosomal aberrations have rather similar anomalies of the ET and its associated structures. We speculate that these anomalies might be closely related to ET dysfunction in these patients.

Two temporal bone-eustachian tube (ET) specimens; one from a 1-day-old female newborn with Townes Syndrome (Case 1) and the other from a 15-year-old female with oral-facial-digital syndrome (Case 2) were studied histopathologically and morphometrically. Both specimens had anomalies of the ET and its associated structures as compared with eight age-matched control cases without anomaly (six cases for Case 1 and two cases for Case 2, respectively). Case 1 had a weak attachment of the tensor veli palatini muscle (TVPM) to a poorly developed lateral lamina (LL) of the ET cartilage, a large voluminous medial lamina (ML) of the ET cartilage, a small voluminous ET lumen with a few ridges of mucosal folds, poorly developed ET glands and a poorly developed levator veli palatini muscle (LVPM). Case 2 had a short and longitudinally elongated ET lumen that was insufficiently covered with a poorly developed ML and LL and an aberrant course of the LVPM. Both cases were accompanied by a mild inner ear anomaly (slightly shortened cochlea). We discuss the implications of the observed anomalies with regard to functional and clinical issues. In particular, we speculate that these ET anomalies may closely be related to potential ET dysfunction with high susceptibility to otitis media.

Six temporal bone-eustachian tube (ET) specimens with cholesterol granuloma (CG), obtained from 6 children 6 months to 15 years of age, were studied histopathologically to obtain further information about the pathogenesis of CG. We observed CG in the mastoid air cells in 5 ears, the mastoid antrum in 1 ear, the aditus ad antrum in 2 ears, and the epitympanum in 1 ear. All 6 cases exhibited a large amount of remaining mesenchyme that was in continuity with the hematopoietic bone marrow in the locations in which CG was present. All cases demonstrated otitis media with effusion and inflammation of the ET. Apparent morphological abnormalities of the ET and its associated structures, including hypoplastic ET cartilage and an abnormal tensor veli palatini muscle, were noted in 3 of the 6 cases. Furthermore, the posterior cartilaginous portion of the ET that includes its narrowest portion was completely filled with effusion in 2 of the 3 cases with the ET anomaly. The findings obtained were compared with data from age-matched control cases. Our results suggest that the source of erythrocytes in the remaining mesenchyme is the hematopoietic bone marrow. The pathogenesis of CG in children is likely promoted by ET dysfunction resulting in failure of ventilation of the middle ear.