Transsphenoidal meningocele: an anatomical study using human fetuses including report of a case.

An asymptomatic transsphenoidal meningoencephalocele was discovered incidentally by fiber laryngoscopic examination in a 62-year-old man suffering from hoarseness due to dysplasia of the vocal cord epithelium. To provide a better understanding of the pathogenesis of this anomaly, we performed histologic observations of paraffin-embedded specimens of 42 human fetal heads at 12-16 weeks of gestation. At these stages, ossification had started in the clivus but the sphenoid sinus was not developed. In contrast to the very low incidence of the intra- or trans-sphenoidal remnant of Rathke's pouch after birth, we found (1) the typical mid-line cleft of the sphenoid body in two specimens (2/42 or 4.8 %) and (2) a duct-like, sellar inferior protrusion ending in the sphenoid body in 12 specimens (12/42 or 28.6 %). The cyst-like structure in the protrusion (two specimens) seemed to be composed of obstructed veins. The intra- and trans-sphenoidal anomalies were observed more frequently in specimens without ossification of the sphenoid body than in those with ossification. However, irrespective of ossification, a cyst-like remnant of the most upper part of Rathke's pouch was always seen between the anterior and posterior lobes of the developing pituitary gland. In addition, the bursa pharyngea was seen in four specimens and we confirmed that the notochord was attached to the bursa in each case. The consistent remnant of the intrasellar Rathke's pouch appeared to explain the high incidence of Rathke's cleft cyst in adults. The relatively high incidence of intrasphenoidal anomalies in fetuses (14/42) suggested that the intra- or trans-sphenoidal remnant of Rathke's pouch was physiologically closed by ossification of the sphenoid body.

A rare expression of neural crest disorders: an intrasphenoidal development of the anterior pituitary gland.

Congenital abnormalities of the pituitary gland are rare and may be associated with midline cranial, orbital, and facial anomalies and with hormonal insufficiency. Here we report a case of asymptomatic, abnormal migration of the adenohypophysis. The normally developed adenohypophysis was located in the sphenoid bone and developed on the intersphenoidal septum, extending from the superior pharyngeal wall to the floor of the sella turcica (craniopharyngeal canal). The abnormal migration of the pituitary gland was isolated without hormonal deficit, brain, or facial developmental anomalies.

Diagnosis and management of the opacified sphenoid sinus.

The growing number of surgical procedures at the base of the skull makes a clear understanding of sphenoid disease and its anatomic relationships important for the modern otolaryngologist. We present five cases demonstrating the spectrum of sphenoid sinus disease, its systemic as well as local complications, and its surgical management. Pertinent anatomic and embryologic relations are reviewed and their diagnostic evaluation is discussed. Pitfalls in the diagnosis and management of these diseases are reviewed noting possible complications and significant danger points. The necessity for cooperation among the otolaryngologist, neurosurgeon, and ophthalmologist in the management of these entities is also demonstrated.

[Developmental studies on the palatine bone in the human skull. With special references to the development of its nasal surface].

For the purpose of these studies 83 cases of fetus skulls and 4 cases of adult skulls were used and the following results were obtained; The palatine bone was found to ossify in a fetus between the middle of the second month and that of the third month. The pyramidal process and conchal crest were first observed in a 9.0 cm fetus. The orbital process, sphenoidal process, sphenopalatine notch and nasal crest were first found in a 16.0 cm fetus. The ethmoidal crest was first found in a 20.0 cm fetus. The posterior nasal spine was first found in a 33.0 cm fetus. The anterior part of the palatal surface of the horizontal plate was found to cover the posterior part of the nasal surface of the palatine process of the maxilla so as to form two layers one above the other. However, the covered surface gradually reduced in size finally to make the transverse palatine suture between the maxilla and the palatine bone in the adult. The transverse length of the horizontal plate was almost equal to its antero-posterior length up until the fifth month fetus, while the former was constantly longer than the latter in the fetus older than the sixth month. The perpendicular plate was constantly longer than the horizontal plate in the fetus older than the fourth month. The metrical comparison between the fetus and the adult revealed that the most well-developing part of the palate bone was the height of the perpendicular plate, which developed 10.9 times longer than that of the fourth month fetus. The rest of the part developed 4.5-5.5 times longer than that of the fourth month fetus.

Agenesis of sphenoid sinuses.

A 22-year-old female patient presented to our hospital complaining of a headache. Evaluation with magnetic resonance imaging (MRI) demonstrated the absence of sphenoid sinus. Agenesis of sphenoid sinus is a rare entity; it usually occurs with syndromes. A case of sphenoid sinus agenesis without any anomaly or syndrome is reported.

Formation and enlargement of the paranasal sinuses in normal and cleft lip and palate human fetuses.

OBJECTIVE: Comparisons of paranasal sinus morphology between humans with and without cleft lip and palate (CLP) have yielded conflicting opinions regarding size differences. Although postnatal samples have been investigated, no studies have compared paranasal sinus volumes between cleft and noncleft human fetuses. METHOD: The nasal cavities of 20 'normal' and 9 CLP human fetuses (8-21 weeks' postmenstrual age) were examined to assess prenatal volumetric changes of the maxillary sinuses, anterior and posterior ethmoidal air cells, and sphenoidal sinuses. Lengths and volumes of right and left maxillary and sphenoidal sinuses were calculated from histologically prepared sections using a computer reconstruction technique, and regression equations were generated to assess the enlargement rates. RESULTS: All paranasal sinuses were found among both normal and CLP specimens in the same locations and in similar age ranges. However, greater shape asymmetry was noted for all sinuses in CLP compared to normal specimens. In the normal sample, results indicated significant (p < .05) correlations between right or left maxillary sinus length (R2 = 0.49, 0.54) and volume (R2 = 0.67, 0.68), and increasing postmenstrual age, but no significant (p > .05) correlations were observed for right or left sphenoidal sinus length or volumes and postmenstrual age. Maxillary sinus length changes were best described by second-order polynomial regression equations, and volume changes were best described by logarithmic equations. When individual right or left sinuses of CLP specimens were compared to the mean of the normal sample, one maxillary sinus was significantly (p < .05) larger, and 9 maxillary sinuses were not significantly (p > .05) different. Sphenoidal sinus lengths and volumes of CLP specimens were within the same range compared to these dimensions for the normal sample. CONCLUSION: Results on normal specimens indicate that maxillary sinuses exhibit second-trimester length and volume increases, whereas sphenoidal sinuses are more variable. This study suggests a similar timing of sinus formation in normal and CLP fetuses, but shape asymmetries are frequently detected among CLP specimens. In particular, the sphenoidal sinuses may be altered in shape and size by adjacent, hypertrophic cartilaginous structures in CLP fetuses. These results indicate that the maxillary sinuses of CLP fetuses are not deficient in size compared to noncleft fetuses.

Pharyngeal pituitary: development, malformation, and tumorigenesis.

The development of the pharyngeal pituitary (PhP) in the fetal period was morphologically and, for the first time, immunohistochemically examined. PhP, found in every individual, begins its hormone production at the 17-18th week of gestation, that is, 4-8 weeks later than that of sellar pituitary (SP). Only 1 of 25 examined fetuses without any stigmata of developmental anomalies showed a residual pituitary fragment in the craniopharyngeal canal (craniopharyngeal pituitary, CPhP). An adult case of a rare clivus pituitary adenoma that we examined is demonstrated in discussing its relationship to PhP. Extracranial ectopic pituitary adenomas in the literature describe an exclusively sphenoid sinus/nasopharyngeal/clivus location of the tumor. Their location corresponded exactly with that of PhP, so that the origin of the tumors can be reasonably speculated as PhP, although another origin, e.g., CPhP, can not be excluded. A variety of malformations of PhP, although very rare, have been described for the fist time during the systemic examination of 16 fetuses with different cranioneural malformations, such as agenesis, unseparated PhP from SP (pharyngosellar pituitary), fragmentation, and residual pituitary tissue in the open craniopharyngeal canal. However, developmental anomaly of PhP was not specifically associated with cranioneural malformations except in cases of chromosomal aberrations. The hormone production in PhP in malformation cases tended to be retarded. Absence of SP was recorded in 50% of anencephalics in the literature; however, PhP was identified in all anencephalics in our series, independent of the existence of SP. This supports the opinion that agenesis of SP in anencephalics seems to be false information.