Relationship between the development of diaphragma sellae and the morphology of the sella turcica and its content

Summary The impaired formation of the diaphragma sellae may lead to the development of the empty-sella syndrome. This structure, when fully formed, is a protective barrier against the pulsating action that the cerebrospinal fluid exerts on the sellar content. There are anatomical features which support this belief, but they also suggest that the development of the diaphragma sellae is a factor which determines the morphology of the sella turcica and its contents. Those human specimens which do not have diaphragma sellae or in which it is only partially developed, are characterized by a smaller hypophysis, always located at the inferior and/or posterior half of the sella, with a larger sellar volume and frequently greater fragility of its bony walls. These findings, although rare (5% of the cases), are indirect signs of the important role which the diaphragma sellae plays in the sellar region.

---

Rapports entre la formation du diaphragme sellaire et la morphologie de la selle turcique et de son contenu

Résumé Le développement incomplet du diaphragme sellaire peut être à l'origine d'un syndrome de la selle turcique vide. Lorsque ce diaphragme est bien formée, il constitue une barrière efficace, protégeant le contenu de la selle turcique de la pression pulsatile du liquide cérébro-spinal. Des études anatomiques semblent corroborer ces données et suggèrent même que le développement du diaphragme sellaire conditionne la morphologie de la selle turcique et son contenu. C'est ainsi que l'on peut observer chez certaines personnes dont le diaphragme sellaire est absent ou partiel, l'existence d'une petite glande pituitaire qui est toujours plaquée à la partie inférieure et/ou postérieure de la selle turcique ; de surcroit, le volume de la selle est augmenté et ses parois osseuses sont plus fragiles qu'à l'accoutumée. Tous ces faits, bien que rares (5% des cas), établissent de façon indirecte le rôle important que joue le diaphragme sellaire sur la région pituitaire.

     

Anatomical bases for the transphenoidal approach to the pituitary gland

Summary The anatomical and surgical problems of the transphenoidal approach to the pituitary gland are described in relation to 116 autopsy studies and more than 300 surgical operations.The variations in bony structure and softer parts were studied at each operation.

---

Bases anatomiques de l'abord transphéno ïdal de l'hypophyse

Résumé D'aprés 116 études autopsiques et plus de 300 interventions chirurgicales, les auteurs envisagent les problèmes, anatomiques et chirurgicaux, que pose le cheminement transphénoïdal vers l'hypophyse.Les variations des structures osseuses et des parties molles sont étudiées au cours de chaque temps opératoire.

     

Postnatal structure of the sella turcica in Down syndrome

The purpose of this study was to analyze the shape of the sella turcica in a group of patients with Down syndrome and compare the findings with those made earlier in human fetuses with Down syndrome. Profile radiographs from 78 patients (age 4 months to 50 3/12 years) were analyzed. A tracing was made of each sella turcica, and the shape was compared with that of a normal sella, including the normal growth pattern from childhood to adulthood. Sella turcica structure could be classified into three morphological types, defined as: type I, almost normal appearance; type II, deviations in the anterior wall; and type III, deviations in the floor of the sella turcica. Compared with previously registered prenatal structural deviations in the sella turcica, it can be concluded that the postnatal radiographic material reflects the prenatal findings, because type I, both prenatally and postnatally, is by far the most common, whereas the remaining types are uncommon, both prenatally and postnatally. The study confirms the relevance of prenatal investigations for postnatal diagnostics as previously documented in sella turcica analyses of prenatal and postnatal myelomeningocele cases. Am. J. Med. Genet. 87:183–188, 1999. © 1999 Wiley-Liss, Inc.     

A reappraisal of the hypophysial region of the floor of the sella turcica

While studying the detailed anatomy of the cranial sella turcica, an additional fossa in its floor, which has not previously been described, was noted. A survey for this fossa, therefore, was conducted on 205 adult crania from the Raymond A. Dart Collection of Human Skeletons, University of the Witwatersrand. To confirm the survey observations, the sella turcica region of 10 adult cadavers was also dissected. A larger anterior depression and a smaller posterior concave fossa, often extending on to the anterior surface of the dorsum sellae, were evident in the hypophysial region and occurred in 21.5% of crania and in six of the 10 dissected specimens. An anterior depression alone or a posterior fossa alone occurred in 2.4% and in 72% of the crania, respectively, indicating that the posterior fossa occurs most commonly in this series. The more commonly occurring presence of a posterior fossa abutting on to the anterior surface of the dorsum sellae is described for the first time.     

Pituitary choristoma composed of corticotrophs and adrenocortical cells in the sella turcica

A pituitary tumour composed of well-differentiated corticotrophs and adrenocortical cells is reported. Sections of the tumour revealed a mixture of small round cells with amphophilic or basophilic periodic acid-Schiff (PAS)-positive cytoplasm and large spherical and oval cells with abundant, granular, partly vacuolated PAS-negative cytoplasm. The small cells contained type 1 cytokeratin-positive microfilaments, numerous 250–500 nm endocrine-type secretory granules immunoreactive for adenocorticotropic hormone (ACTH) and -lipotropin. The large cells possessed ample cytoplasm filled with abundant vesicular smooth endoplasmic reticulum, numerous mitochondria possessing tubulovesicular cristae and frequent dense bodies. They lacked the features of pituitary endocrine cells or folliculostellate cells and were found to contain a panel of steroidogenic dehydrogenases and hydroxylases. The tumour was classified as a choristoma, in which two distinct cells types, corticotrophs and adrenocortical cells, were mixed. We suggest that, under continued ACTH stimulation, uncommitted stem cells may differentiate into adrenocortical cells. Alternatively, the presence of adrenocortical cells may be the result of heterotopia.     

Infratentorial giant cell ependymoma: a rare variant of ependymoma

We describe a giant cell ependymoma occurring in a 50-year-old man. The mass was located in the posterior aspect of the foramen magnum, extending from the cerebellar tonsil to the upper cervical spine. The tumor was a highly cellular neoplasm showing biphasic histology. Diffuse sheets of non-cohesive atypical giant cells, having eccentrically located single or multiple nuclei and plump eosinophilic cytoplasm, partly infiltrated the desmoplastic inflammatory stroma. Parts of perivascular pseudorosette-forming or pseudopapillary areas were composed of atypically elongated cells, which looked like conventional anaplastic ependymoma. There was a transitional area between two patterns. Numerous mitoses and focal necrosis were observed. Immunohistochemically, the tumor cells were immunoreactive for glial fibrillary acidic protein, vimentin, S-100 protein, and CD99. None of the tumor cells showed immunoreactivity for epithelial membrane antigen except for the intracytoplasmic lumen of a few vacuolated cells. Ultrastructurally, tumor cells were ependymal in nature; we noted cytoplasmic intermediate filaments and intercellular microrosettes with microvilli, cilia, and long zonula adherens. The features of this tumor, e.g. its superficial location, mixed giant cells, perivascular pseudorosettes or papillaries, complicated its differentiation from rhabdoid/papillary meningioma. However, immunohistochemistry and electron microscopy confirmed the diagnosis of ependymoma. The giant cell variant should be included in the subclassification of the ependymoma.     

Adult variant of atypical teratoid/rhabdoid tumor: Immunohistochemical and ultrastructural confirmation of a rare tumor in the sella tursica

Atypical teratoid/rhabdoid tumor (AT/RT) is a distinctive neoplasm of young children characterized by diverse histology and fatal course. Adult presentation is rare. We describe the diagnostic problems associated with an AT/RT arising in the sellar region in a 46-year-old female.     

Suprasellar giant cell ependymoma: a rare neoplasm in a unique location

Ependymomas are glial tumors that usually present in the posterior fossa in children and in the spinal cord in adults. Giant cell ependymoma, a rare ependymal subtype only recently recognized as a diagnostic entity in the last decade, demonstrates pleomorphic giant cells admixed with features of typical ependymoma. Although only 8 giant cell ependymomas have been reported to date, none have been reported in the suprasellar space. Moreover, as these neoplasms demonstrate a high incidence of anaplastic grade, recognition of this ependymal subtype is paramount. We describe the presentation and pertinent radiologic, histologic, immunologic, and ultrastructural findings in conjunction with relevant clinical implications of the first reported case of a suprasellar giant cell ependymoma occurring in a 34-year-old female 7 years after an initial diagnosis of a medullary ependymoma with rare atypical giant cells, a potential tumor seeding culprit.     

Anaplastic Ependymoma of the Spinal Cord in Childhood A Case Report

We report a 6-year-old girl with anaplastic ependymoma probably originating in the region of the conus medullaris and probably spreading retrogradely to the region of the interventricular foramen (Monro) through the cere-brospinal fluid (CSF). Since ependymoma of the spinal cord rarely occurs in children, and retrograde spreading is extremely rare, the histological features and mechanism of metastasis of the tumor are discussed.     

The differential diagnosis of lesions involving the sella turcica

The sella turcica and the surrounding area contain several different tissues varying in morphology and cytogenesis. Thus, it is not surprising that a large number of diverse lesions may arise in the sellar region. The most frequent abnormalities are the pituitary adenomas, which based on histology, immunocytochemistry, and transmission electron microscopy can be classified into several distinct entities. Pituitary adenomas originate in and consist of adenohypophyseal cells. They are usually slowly growing benign epithelial tumors, which may be associated with increased hormone secretion or may be endocrinologically nonfunctioning. Pituitary carcinomas also arise in adenohypophyseal cells. They are rare and can be diagnosed only when cerebrospinal and/or systemic metastases are documented. To illustrate the diversity, practical importance, and diagnostic difficulties, four cases were selected for presentation: lymphocytic hypophysitis, thyrotroph hyperplasia, growth hormone-producing pituitary adenoma with neuronal transformation, and composite tumor consisting of adenomatous periodic acid Schiff-positive as well as adrenocorticotropic hormone-immunoreactive adenohypophyseal cells and adrenocortical cells. The first two cases are important from a practical point of view because the proper diagnosis can easily be missed, and appropriate interpretation of the findings is essential to prognosis and treatment. The latter two cases are odd, unusual entities; their histogenesis is unresolved. Study of these and many other cases convinced us that careful and detailed morphologic investigation of lesions involving the sella turcica is of fundamental significance. Histology, immunocytochemistry, transmission electron microscopy, and, in some cases, molecular methods are essential to reach a correct diagnosis and to draw conclusions on histogenesis, growth potential, biologic behavior, prognosis, and therapeutic responsiveness.     

Ultrastructure,immunohistochemistry and hormone release of pituitary adenomas in relation to prolactin production

Summary Fifteen cases of pituitary adenoma, 14 of which were associated with hyperprolactinemia, were studied by observation and granule morphometry of electron micrographs, immunohistochemistry and sequential observation of in vitro release with regard to hormone production, storage and secretion. Adenoma cells of 6 cases with marked elevation of plasma prolactin were sparsely granulated, showed characteristic ultrastrucures including the presence of small secretory granules, well developed Golgi and rough membranes, misplaced exocytosis, and positive or negative immunostaining for prolactin. These adenomas also showed vigorous release of the hormone into the circulation and/or culture medium. In vitro studies showed that negative immunostaining of adenoma cells did not preclude the production and secretion of the hormone. One densely granulated adenoma containing cells with numerous lactotroph type granules showed moderate release of prolactin into the circulation. In an acromegalic case associated with both high plasma growth hormone and prolactin, some cells were shown by immunohistochemistry to store both hormones. There were 4 adenomas which could not be shown to produce, store and secrete prolactin by any method available.Abbreviations Used in this Paper ACTH adrenocorticotropic hormone - -MSH -melanocyte stimulating hormone - hGH human growth hormone - hPRL human prolactin - LH luteinizing hormone - FSH follicle stimulating hormone - TSH thyroid stimulating hormone - TRH Thyrotropin-releasing hormone This work was supported in part by Grants-in-Aid for Cancer Research (No. 50-14) and for Specific Diseases (Disorder of Hypothalamic and Pituitary System) from the Ministry of Health and Welfare, and for Cancer Research (No. 401034) from the Ministry of Education, Science and Culture, Japan     

Atypical presentations of solitary fibrous tumors of the central nervous system: an analysis of unusual clinicopathological and outcome patterns in three new cases with a review of the literature

Central nervous system (CNS) solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms recognized less than a decade ago. Approximately 60 cases of SFT have been reported in the central nervous system. We describe three atypical SFTs of the CNS, two intracranial and one within the spine. One intracranial SFT arose from the sella turcica and expanded into the suprasellar areas. It relapsed twice during the 3 years following partial resection, and the MiB1 labeling index steadily increased without obvious malignant transformation. The second SFT arose from the confluence of the sinuses, widely invaded the lateral sinus and adjacent bones, had a low MiB1 index and has not recurred after 5 years. The intraspinal tumor occurred at T5–T7 in a patient with multiple café-au-lait spots, was predominantly myxoid and developed a second similar lesion at S3–S5 14 years later. The MiB1 index was lower in the second tumor. Immunohistochemistry confirmed that all were SFTs. These atypical presentations gave us an opportunity to provide further information about the natural histological course of CNS SFTs.     

垂体促甲状腺素腺瘤的临床病理分析

目的 研究垂体促甲状腺素(TSH)腺瘤的临床及病理学特点。方法 利用光镜、电镜观察和免疫组织化学链霉素抗生物素蛋白一过氧化物酶法(SP法),结合临床资料对7例垂体TSH腺瘤进行临床病理分析。结果 7例患者均有甲状腺功能亢进的临床表现,血浆FT3、FT4、T3、T4均增高,血浆TSH不被抑制。蝶鞍MRI检查均为垂体大腺瘤或巨大腺瘤(直径2～5cm),光镜下显示5例为嫌色细胞性腺瘤,1例为弱嗜酸和嫌色细胞性腺瘤,1例为嗜酸细胞性腺瘤。免疫组织化学染色7例TSH强阳性,1例合并泌乳素阳性,2例合并生长激素阳性,3例合并散在生长激素和泌乳素阳性,Ki-67标记7例阳性率为0～0．4％,p53标记7例均为阴性。结论 7例垂体TSH腺瘤虽然都为大腺瘤和巨大腺瘤,1例侵犯额叶底部和第三脑室,但它们的增殖指数均在正常范围,肿瘤的复发与肿瘤侵犯周围组织不能彻底切除有关。     

Expression,purification, and characterization of a novel laccase from Setosphaeria turcica in Eschericha coli

Laccases are multicopper oxidases (E.C. 1.10.3.2) that catalyze the oxidation of many phenolic compounds. In this study, a novel laccase, Stlac4, from Setosphaeria turcica was cloned and expressed in Escherichia coli by insertion into the pET‐30a expression plasmid. The recombinant laccase was purified and visualized on SDS–PAGE as a single band with an apparent molecular weight of 71.5 KDa, and confirmed by Western blot. The maximum activity of the purified laccase was 127.78 U · mg^?1, the optimum temperature and pH value were 60 °C and 4.0 respectively, measured by oxidation of 2,2′‐Azinobis‐(3‐ethylbenzthiazoline‐6‐sulphonate) (ABTS). Purified laccase activity under different metal ions and an inhibitor were tested, revealing that laccase activity increased by approximately 434.8% with Fe³⁺, and 217.4% with Cu²⁺ at 10 mmol · L^?1 concentrations, Mn²⁺ increased the laccase activity only at 5 mmol · L^?1, while Na⁺ increased activity at 1 mmol · L^?1 but inhibited activity at 5 and 10 mmol · L^?1. SDS increased laccase activity at 1 mmol · L^?1, and inhibited activity at 5 and 10 mmol · L^?1.     

Myofibrosarcoma of the Upper Jawbones: A Clinicopathologic and Ultrastructural Study of Two Cases

Two problematic spindle cell sarcomas involving upper jawbones in two adult male patients have been studied by histology, immunohistochemistry, and transmission electron microscopy, and respectively graded as low-grade malignancy and high-grade malignancy. While any single methodological study did not allow confident classification of them into one or other of the classical categories of spindle cell sarcomas (fibrosarcoma versus leiomyosarcoma), the overall contribution from all three methodologiesultimately allowed them to be categorized as sarcomas with myofibroblastic differentiation. Histologically, both tumors had morphological features of an amalgama between neoplastic fibroblasts and smooth muscle cells. Immunohistochemically, both tumors expressed reactivity only for muscle specific actin and alpha smooth muscle actin, in addition to vimentin. Ultrastructurally, both tumors, while showing fibroblast-like cytoplasmic features, had a spurious and imperfectly organized cell surface defying convincing classification into any of specific categories (i.e., both appeared in terms of ultrastructure as poorly differentiated sarcoma, the former with low level of smooth muscle differentiation and possibly the presence of some fibronexus component, the latter with no smooth muscle differentiation but with possible evidence of very rare fibronectin fibril). Therefore, on balance, the most tenable diagnosis seemed to us that of a myofibrosarcoma in both cases. This work is presented considering the fact that myofibrosarcoma currently represents a topical theme of debate, and that this is the first report in medical literature concerning with myofibrosarcomas of the head and neck area in adults.     

Ultrastructural examination of the regeneration of the rat adenohypophysis after partial hypophysectomy

Summary Male Wistar rats were partially hypophysectomized and sacrificed at intervals of from 2 days to 1 year following the operation. The resected material was examined under the light microscope and the residual pituitary under the light and electron microscope. Neither regeneration nor an anatomical restoration of the adenohypophysis occurred even one year after partial hypophysectomy. An increased number of small chromophobe stem cells and juvenile chromophil cells were found in the residual pituitary. The amount of mitoses were not significantly increased.The ACTH, FSH and prolactin producing cells demonstrated electron microscopically distinct changes which were interpreted as signs of intensified activity. This can be seen as a functional regeneration to maintain vital pituitary function for the organism.Supported by the Sonderforschungsbereich 34 (Endocrinology) of the Deutsche Forschungsgemeinschaft     

The ultrastructure of the pituitary and the adrenal gland of three newborn marsupials (Dasyurus hallucatus, Trichosurus vulpecula and Isoodon macrourus)

Summary The ultrastructure of the pituitary glands of the newborn northern native cat, brushtail possum and the northern brown bandicoot and the adrenal glands of the former two marsupials were examined to determine whether these endocrine glands were functional at birth.The anterior pituitary of all three species was well vascularised and many cells contained electron-dense, membrane bound granules. The adrenal glands were composed of two distinct cell populations. One group of cells possessed dark staining granules, normally observed in catecholamine-secreting cells, and the second group contained large amounts of smooth endoplasmic reticulum and mitochondria with tubulovesicular cristae, indicative of steroid hormone secreting cells.The ultrastructure of the cells of the fetal pituitary and adrenal of all three species would suggest that these glands are functional at birth and, as with many eutherians, the marsupial pituitary and adrenal gland may play an important role in determining the length of gestation.